Sampling and Analysis of Nanomaterials in the Environment: a State-Of-The-Science Review

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Sampling and Analysis of Nanomaterials in the Environment: A State-of-the-Science Review

Final Report

R E S E A R C H A N D D E V E L O P M E N T

EPA/600/R-08/098 September 2008 www.epa.gov

Sampling and Analysis of Nanomaterials in the Environment: A State-of-the-Science Review

Final Report

Prepared for

U.S. Environmental Protection Agency Office of Research and Development National Exposure Research Laboratory Environmental Sciences Division 944 E. Harmon Ave. Las Vegas, NV 89119

Prepared by

Eastern Research Group, Inc. 10200 Alliance Road, Suite 190 Cincinnati, OH 45242

Scientific, Technical, Research, Engineering, and Modeling Support (STREAMS)

Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. Mention of trade names and commercial products does not constitute endorsement or recommendation for use.

U.S. Environmental Protection Agency Office of Research and Development Washington, DC 20460 3263cmb08

Notice

The U.S. Environmental Protection Agency (U.S. EPA), through its Office of Research and Development (ORD), funded and managed the research described here. It has been subjected to the Agency’s peer and administrative review and has been approved for publication as an EPA document.

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Table of Contents

Executive Summary...... 1

List of Acronyms...... 2

1.0 Introduction and Scope of Review ...... 3 2.0 Information Search Strategy...... 4 2.1 Dialog® Search Strategy and Results...... 4 2.1.1 Dialog® Search Parameters...... 5 2.1.2 Dialog® Search Procedure and Results...... 5 2.2 Targeted Search of Sources ...... 9 2.2.1 Nano-specific Journals...... 9 2.2.2 Conference Proceedings...... 12 2.2.3 Databases of Nanotechnology Research...... 13 2.2.4 Grant Databases ...... 13 2.3 List of Contacted Researchers ...... 14 2.4 Results of Literature Search and Potential Future Reviews...... 15 3.0 Background...... 23 3.1 Overview of Nanomaterials ...... 23 3.1.1 Natural Nanomaterials ...... 23 3.1.2 Anthropogenic Nanomaterials ...... 24 3.2 Overview of Environmental Transport ...... 27 3.2.1 Surface Water Transport...... 27 3.2.2 Soil Transport...... 29 3.2.3 Groundwater Transport...... 30 4.0 Sampling Techniques ...... 31 4.1 Sampling Techniques Suited for Surface Waters ...... 32 4.2 Sampling Techniques Suited for Sediments ...... 32 4.3 Sampling Techniques Suited for Soil ...... 33 4.4 Sampling Techniques Suited for Groundwater...... 34 4.5 Comparison of Sampling Techniques...... 34 5.0 Analytical Techniques...... 34 5.1 Analytical Techniques for Size Fractionation...... 36 5.2 Analytical Techniques for Size Distribution...... 39 5.3 Analytical Techniques for Surface Area...... 42 5.4 Analytical Techniques for Direct Visualization ...... 43 5.5 Analytical Techniques for Phase and Structure...... 44 5.6 Analytical Techniques for Chemical Analysis ...... 46 5.7 Comparison of Analytical Techniques...... 51 6.0 Differentiation of Anthropogenic Nanomaterials...... 55 7.0 Summary...... 55

Table of Contents (continued)

8.0 References ...... 57

Appendices

Appendix A Dialog® Search Output

Executive Summary

This state-of-the-science review was undertaken to identify and assess currently available sampling and analysis methods to identify and quantify the occurrence of nanomaterials in the environment. The environmental and human health risks associated with nanomaterials are largely unknown, and methods needed to monitor the environmental occurrence of nanomaterials are very limited or nonexistent. Because this research is current and ongoing, much of the applicable information is found in gray literature (e.g., conference proceeding, communications with research scientists and other experts).

The approach to this review included three separate strategies:

• Collection of available published literature using Dialog®; • Review of information from targeted sources, such as nano-specific journals, conference proceedings, grants databases, and research databases; and • Contacts with industry and academic experts.

This report summarizes the key characteristics that must be considered when collecting and analyzing samples in various environmental media. Based on results of the literature review, and personal communication with researchers, typical analytical methods and techniques that are currently used for nanomaterials are identified and briefly discussed.

The review also identifies several sources that provided information on analytical techniques and equipment for nanomaterials. However, little information was obtained for sampling techniques that are specific for analysis of nanomaterials. Information obtained indicated that nanomaterial- specific sampling techniques have not yet been developed. Another area for which the search results provided little information is for differentiating anthropogenic (man-made) nanomaterials from natural nanomaterials. A number of potential sources that may provide additional information upon a more in-depth review were identified. As this report provides a current state- of-the-science review of active research topics at the time of writing, this report may require modifications as additional research is conducted.

LIST OF ACRONYMS

Acronym Definition AAS Atomic Absorption Spectrometry AEM Analytical Electron Microscopy AES Atomic Emission Spectrometry AFM Atomic Force Microscopy BET Brunauer-Emmett-Teller method CBED Convergent Beam Electron Diffraction CCD Charged Coupled Device CE Capillary Electrophoresis DLS Dynamic Light Scattering EDS Energy Dispersive Spectroscopy EDX Energy-Dispersive X-ray Spectroscopy EELS Electron Energy Loss Spectroscopy EFTEM Energy-Filtered Transmission Electron Microscopy ESEM Environmental Scanning Electron Microscopy ETEM Environmental Transmission Electron Microscopy FFF Field-Flow Fractionation FLD Fluorescence Detector FlFFF Flow Field-Flow Fractionation GF Graphite Furnace HAADF High-Angle Annular Dark Field HPLC High-Performance Liquid Chromatography HR High Resolution ICP Inductively-Coupled Plasma LIBD Laser-Induced Breakdown Detection LC Liquid Chromatography MALLS Multi-Angle Laser Light Scattering MS Mass Spectrometry NMR Nuclear Magnetic Resonance RTM Resonant Tunneling Model SAED Selected-Area Electron Diffraction SAXS Small-Angle X-ray Scattering SEC Size Exclusion Chromatography SEM Scanning Electron Microscopy SIMS Secondary Ion Mass Spectrometry SPM Scanning Probe Microscopy STEM Scanning Transmission Electron Microscopy STM Scanning Tunneling Microscopy TEM Transmission Electron Microscopy TFF Tangential-Flow (cross-flow) Ultrafiltration UV Ultraviolet radiation XAS X-ray Absorption Spectroscopy XEDS X-ray Energy-Dispersive Spectroscopy

XPS X-ray Photoelectron Spectroscopy XRD X-ray Diffraction WAXS Wide-Angle X-ray Scattering

1.0 INTRODUCTION AND SCOPE OF REVIEW

The rapidly advancing field of nanotechnology offers potential benefits to almost all industries and products. According to the Woodrow Wilson International Center for Scholars’ Project on Emerging Nanotechnology’s Nanotechnology Consumer Product Inventory, nanomaterials are currently being used in over 500 consumer products. However, the environmental and human health risks associated with these materials are largely unknown. Before the environmental and general population risk of these materials can be measured or monitored, methods will be needed to collect, separate, detect, identify, and quantify the occurrence of nanomaterials in the environment over time. The rate of product development has outpaced the rate of methods development, and, unfortunately, the methods needed to monitor the environmental occurrence of nanomaterials are very limited or nonexistent. Only limited research has been conducted, in part due to the immense challenges of sampling nanomaterials in the environment (e.g., distinguishing between naturally-occurring nanoparticles and engineered nanoparticles). While EPA’s Office of Research and Development (ORD) may eventually sponsor research to develop remote, in situ, and continuous monitoring devices to detect engineered nanomaterials at very low concentrations, the purpose of this initial effort is to identify and assess currently-available sampling and analysis methods. This report focuses on soil, sediment, and groundwater environmental sampling. A companion research effort is focusing on air sampling and analytical techniques.

Due to the limited data available and the rapid advancements that are being made, a traditional literature search (i.e., using an abstract database to search peer-reviewed journals) is not expected to effectively capture the cutting-edge information on environmental sampling and analysis methods for nanomaterials, particularly those under development and those that have not been fully peer-reviewed. Because this research is current and ongoing, much of the applicable information is found in gray literature (e.g., conference proceeding, communications with research scientists and other experts). Additionally, many of the techniques for environmental sampling and analysis of nanomaterials may need to be adapted from trace sampling methods and methods used in quality assurance or characterization of manufactured nanomaterials; therefore, peripheral literature has also been identified and reviewed. Section 2.0 presents the technical approach that was used to conduct the information search for this report.

As this report provides a current state-of-the-science review of active research topics at the time of writing, this report may require modifications as additional research is conducted.

2.0 INFORMATION SEARCH STRATEGY

A detailed information search to support EPA’s review of sampling and analysis procedures for detecting and monitoring nanomaterials in complex environmental matrices was conducted. The approach to this search included three separate, but parallel, strategies described in the following subsections:

y Section 2.1 describes the collection of available published literature using Dialog® (Search Strategy #1);

y Section 2.2 describes the review of information from targeted sources, such as nano-specific journals, conference proceedings, grants databases, and research databases (Search Strategy #2); and

y Section 2.3 describes contacts with industry and academic experts (Search Strategy #3).

The approach generally included the following steps:

1. Conduct an initial review focused on targeted sources;

2. Evaluate information collected during initial review and identify topic areas that require additional information; and

3. Review additional sources to identify articles, presentations, or research that could provide the needed information.

Initial efforts focused on reviewing a targeted list of journal articles under Search Strategy #2 and contacting industry experts under Search Strategy #3. Additional resources were also identified using the Dialog® search results, a list of nano-specific journals, conference proceedings, grants databases, and research databases.

2.1 Dialog® Search Strategy and Results

The Dialog® search produced two lists of titles of potentially-relevant articles:

y Fifty-eight titles pertaining to characterization and sampling to detect nanomaterials in the environment (Appendix A-1); and

y Sixty-one titles pertaining to the use of nanomaterials for environmental remediation (Appendix A-2).

This subsection describes the parameters that were specified for the Dialog® search, the search procedure and results, and next steps.

2.1.1 Dialog® Search Parameters

The parameters that were specified for the DIALOG search include keywords, publication date, languages, and the list of databases included in the search.

Keywords: Keywords were searched in the “title,” “abstract,” and “descriptor” fields.

y Primary Keyword: “nano*”

This was identified as a keyword, assuming it would capture the following words of interest: nanomaterial, nanoparticle, nanoscale.

y Secondary Keywords:

− “soil” or “air” or “water” or “sediment” or “environment*” or “ground*” or “expos*”

− “analy*” or “sampl*” or “remediat*” or “contamina*” or “characteriz*” or “anthropogenic*” or “manufactur*” or “fate” or “transport” or “separat*” or “detect*” or “monitor*”

Words of interest these secondary keywords were expected to encompass include: samples, sampling, analysis, analytical, soil, air, water, sediment, remediation, contaminants, contamination, anthropogenic, environment, environmental, characterize, characterization, ground, groundwater, manufactured, manufacturing, fate, transport, separate, separation, detect, detection, monitor, monitoring, exposure, expose.

Publication Dates: The Dialog® search included all articles published in the year 2000 and later.

Language: Only articles published in English were evaluated.

Databases: Thirty databases were included in the search (see Table 2-1 for the list). These were identified by evaluating the Dialog® subject guide in “Science - Energy & Environment” and “Science - Engineering & Technology.”

2.1.2 Dialog® Search Procedure and Results

Figure 2-1 shows a decision-making flowchart for the Dialog® literature search. This flowchart describes the search procedure and the results of each step:

1. Dialog® was run using the specified parameters described in the previous section. The Dialog® output produced approximately 585 unique records.

2. The search was then modified by removing the keywords “remediat*,” “air,” and “manufactur*.” However, the Dialog® output continued to produce more than 400 records.

3. It was determined that the list of 585 records could be reviewed manually within a reasonable timeframe; therefore, a list of titles to identify those pertaining to characterization and sampling for nanomaterials in the environment was prepared. This initial review identified a list of 58 potentially-relevant titles.

4. Abstracts and citations for the 58 potentially-relevant titles (see Table A-1 of Appendix A) were obtained. Based on information provided in the abstract, unrelated articles and articles of interest were identified. This review identified 14 articles of interest (identified in Table A-1), which were obtained and evaluated for this report. Articles that are cited in this report are presented in Table 2-6 at the end of this section.

5. In addition, it was determined that a list of titles pertaining to the use of nanomaterials for environmental remediation may be useful (if not for this project, then potentially for future efforts). The use of nanomaterials for environmental remediation may be of interest to EPA because it is a mechanism by which nanomaterials enter the environment. Table A-2 of Appendix A lists 61 titles that were identified as potentially pertaining to the use of nanomaterials for environmental remediation.

Table 2-1 lists databases that were included in the Dialog® search and the number of hits per database for the initial search.

Run DIALOG® and view number of records

Do the specified search parameters produce a No Modify search reasonable number of parameters records (<200 records)? Yes: Print list of titles.

Do the majority of the titles No seem relevant? Yes: Print list of citations and abstracts. Identify articles of interest. Obtain full text of Is the full text of the article No available on DIALOG® and article by alternate less than $10? means (library, etc.)

Retrieve article from DIALOG®

Figure 2-1. DIALOG® Literature Search Flow Chart

Table 2-1. List of Databases Included for DIALOG® Search and Results

Number of Number of Hits Hits Pertaining to Pertaining to Database Characterization Environmental Number Database Name and Sampling Remediation 6 NTIS - National Technical Information Service 0 0 9 Business & Industry™ 0 0 19 Chemical Industry Notes (CIN) 2 0 31 World Surface Coatings Abstracts™ 1 0 32 METADEX® 0 0 34 SciSearch® - a Cited Reference Science Database - 1990 28 36 35 Dissertation Abstracts Online 5 8 36 MetalBase 0 0 40 Enviroline® 0 3 41 Pollution Abstracts 2 1 57 Electronics and Communications Abstracts 0 0 60 ANTE: Abstracts in New Technologies and Engineering 0 0 64 Environmental Engineering Abstracts 0 0 65 Inside Conferences 8 6 73 EMBASE® (1974-present) 4 0 76 Environmental Sciences 3 1 95 TEME - Technology and Management 1 0 99 Wilson Applied Science & Technology Abstracts 0 0 103 Energy Science and Technology 1 2 110 WasteInfo 0 0 245 WATERNET™ 1 0 293 Engineered Materials Abstracts® 0 1 315 Chemical Engineering and Biotechnology Abstracts 0 1 317 Chemical Safety Newsbase 2 1 322 Polymer Online 0 0 323 RAPRA: Rubber and Plastics 0 0 335 Ceramic Abstracts/World Ceramics Abstracts 0 0 369 New Scientist 0 0 370 Science 0 0 636 Gale Group Newsletter Database 0 1 Total 58 61 For more information on databases, see http://library.dialog.com/bluesheets/.

Appendix A-3 lists approximately 470 titles that were not selected for further analysis based on their titles and expected content. Examples of common keywords and phrases that were found in the unrelated titles include the following:

"nanogram," "nanometer," "nanomolar," "nanofiltration," "nanofilm detectors," "nanofiber filters," "nano composite membranes," "nanoemulsion," "growth/preparation/synthesis and characterization of nanomaterials," and "application of nanomaterials in environmental detection."

2.2 Targeted Search of Sources

This subsection describes the review of targeted sources (Search Strategy #2), which includes four groups of targeted sources:

y Nano-specific journals; y Conference proceedings; y Databases of nanotechnology research; and y Grant databases.

2.2.1 Nano-specific Journals

As a first step, 24 journal articles were acquired and reviewed that were recommended by industry and academia experts as good sources of information on sampling and analytical techniques for detecting and quantifying nanomaterials in the environment. Additional articles were added to this list from personal contacts with industry experts (described in Section 2.3) and from the Dialog® literature search (described in Section 2.1).

Table 2-6, at the end of this section, presents the entire list of articles reviewed for this report and notes the general topics covered by each.

Table 2-2 presents a preliminary list of targeted journals for this review. Articles reviewed for this report include 4 of the 16 targeted journals. The remaining 12 journals may provide a starting point for future research efforts.

Table 2-2. Preliminary List of Journals to Review for Search Strategy #2

Nano-Specific Journals Environmental Pollution* Nanorisk Newsletter Nanotechnology NanoNow Journal of Nano Research Journal of Particle and Fiber Nanotoxicology Nanobiotechnology Toxicology Journal of Environmental Journal of Nanoparticle Journal of Environmental International Journal of Monitoring* Research* Engineering Nanoscience (IJN) Environmental Nano Letters (American Journal of Nanoscience and Fullerenes, Nanotubes Monitoring and Chemical Society)* Nanotechnology and Carbon Assessment Nanostructures *Journal was included in literature review.

Table 2-3 lists the top 20 nanoscience and nanotechnology journals and the top 20 environmental sciences journals ranked by their 2006 impact factors. The impact factor is the ratio of the number of times journal articles published in the previous two years were cited during a particular year to the total number of citable items that the journal published in the two previous years; for example:

A = the number of times articles published in 2004 and 2005 were cited during 2006

B = the number of citable items published by the journal in 2004 and 2005

Impact Factor = A/B

The impact factor provides a measure of the importance of a journal to its field. This literature search has identified articles in the following journals listed in Table 2-3:

y Nano Letters; y Journal of Nanoparticle Research; y Environmental Science and Technology; and y Environmental Pollution.

Future research could focus search efforts on other journals with high impact factors.

Table 2-3. List of Top Nanotechnology and Environmental Sciences Journals by Impact Factor

Total Impact Journal Title ISSN Citations Factor Top Nanoscience and Nanotechnology Journals Nano Letters 1530-6984 19,403 9.960 Small 1613-6810 1,240 6.024 Lab Chip 1473-0197 2,879 5.821 Biosensors Bioelectronics 0956-5663 7,198 4.132 Nanotechnology 0957-4484 6,798 3.037 Micropor. Mesopor. Mat. 1387-1811 6,264 2.796 Microfluid nanofluid 1613-4982 117 2.615 IEEE T. Nanobiosci. 1536-1241 316 2.592 Biomedical Microdevices 1387-2176 620 2.551 J. Micromech. Microeng. 0960-1317 3,839 2.321 Journal of Nanoscience and Nanotechnology 1533-4880 1,755 2.194 Scripta Materiala 1359-6462 8,571 2.161 J. Nanopart. Res. 1388-0764 870 2.156 Current Nanoscience 1573-4137 60 2.080 IEEE T. Nanotechnol. 1536-125X 713 1.909 Journal of Vacuum Science and Technology B 1071-1023 10,633 1.597 Material Science and Engineering, A Structural Materials 0921-5093 18,437 1.490 Microelectornic Engineering 0167-9317 3,817 1.398 Journal of Microlithography, Microfabrication, and Microsystems 1537-1646 304 1.243 Physical E. 1386-9477 2,854 1.084 Top Environmental Science Journals Environmental Health Perspectives 0091-6765 14,434 5.861 Frontiers in Ecology and the Environment 1540-9295 900 4.842 Global Change Biology 1354-1013 5,729 4.339 Environmental Science and Technology 0013-936X 44,915 4.040 Global Biogeochemical Cycles 0886-6236 5,597 3.796 Conservation Biology 0888-8892 11,192 3.762 Annual Review of Environment and Resources 1543-5938 190 3.080 Remote Sensing of Environment 0034-4257 8,817 3.064 J. Paleolimnol 0921-2728 1,925 3.016 J. Aerosol Science 0021-8502 4,040 2.952 J. Aerosol Science and Technology 0278-6826 3,112 2.905 Conservation Biology 0006-3207 8,759 2.854 Critical Reviews in Environmental Science and Technology 1064-3389 733 2.769 Environmental Pollution 0269-7491 8,569 2.769 Environmental and Molecular Mutagenesis 0893-6692 2,351 2.653 Applied Catalysis A: General 0926-860X 15,023 2.630 Atmospheric Environment 1352-2310 19,210 2.630 Environment International 0160-4120 2,762 2.626 Reviews of Environmental Contamination and Toxicology 0179-5953 701 2.619 International Journal of Hydrogen Energy 0360-3199 3,790 2.612

2.2.2 Conference Proceedings

Table 2-4 presents a preliminary list of conferences to review for the targeted search. The DIALOG® search identified three additional conferences that may be sources of applicable papers/presentations:

y The 4th International Surface Engineering Congress & Exhibition, St. Paul, MN (August 2005);

y Institut fur Festkorperforschung (Institute of Solid State Research) IFF, Germany (March 2002);

y NSTI Nanotech, the Nanotechnology conference and trade show, Anaheim, CA (May 2007);

y The 7th International Symposium on Nanocomposites and Nanoporus materials (ISNAM7), Gyeongju, Korea (February 2006); and

y BioMEMS and nanotechnology, Perth, Australia (December 2003).

Table 2-4. Preliminary List of Conferences to Review for Search Strategy #2

Nano-Specific Conferences International Symposium on Nanotechnology in Experimental Analysis of Nano and Engineering Environmental Protection and Pollution. Hong Kong. Materials and Structures ICEM 13. Alexandroupolis, June 18 - 21, 2006 Greece. July 01 - 06, 2007 "Nanotechnology and Health: Evidence and Impact," Nanoparticles for European Industry II. London, UK. Ann Arbor, MI. October 25 - 26, 2007 October 24 - 25 2007 11th International Conference Detection Technologies Material Characterization of Nanoscale Materials Peer 2007. San Diego, CA. November 01 - 02, 2007 Consultation. U.S. September 6-7, 2007 3rd International Symposium on Nanotechnology, International Conference on Nanotechnology Occupational and Environmental Health. Taipei, Occupational and Environmental Health & Safety: Taiwan, August 29 - September 1, 2007 Research to Practice. December 03 - 08, 2006 Pollution Prevention through Nanotechnology, U.S. Nanotechnology - Products and Processes for September 25-26, 2007 Environmental Benefit. London, UK, May 15-16, 2007 Safer Nano 2006. Beaverton, Ore. March 06 - 07, 2006 Nanoforum 2007. Milan, Italy, September 18 - 19 2007 TMS 2007 Symposium: Towards Functional 3rd International Conference on Humanoid, Nanomaterials – Synthesis, Characterization, and Nanotechnology, Information Technology, Applications. Orlando, FL. February 25 - March 1, 2007 Communication and Control, Environment, and Management. Manila. March 15 - 18, 2007 Aerosol and Particle Measurement Short Course. Nanotechnology and Toxicology in Environment and Minneapolis, MN. August 20 - 22, 2007 Health. Leipzig, Germany. March 27, 2007 OECD Working Party on Manufactured Nanomaterials. Technology, Characterization and Fabrication at the Berlin, Germany. April 25 - 27, 2007 Nanoscale. Atlanta, GA. July 24 - 25, 2007

This state-of-the-science review does not include information from the above list of conferences. Conferences listed in Table 2-4 could provide a starting point for future research.

2.2.3 Databases of Nanotechnology Research

The following publicly-available databases listing nanotechnology environmental and human health research were identified:

y International Council on Nanotechnology (ICON)’s Environmental Health and Safety Database (http://icon.rice.edu/research.cfm);

y Project on Emerging Nanotechnologies’s Inventory of Current Nanotechnology Health and Environmental Implications Research (http://www.nanotechproject.com/index.php);

y National Institute for Occupational Safety and Health (NIOSH)’s Nanoparticle Information Library (NIL) (http://www2a.cdc.gov/niosh-nil/index.asp); and

y Institute of Occupational Health’s (UK) SAFENANO Publication Database Search (http://www.safenano.org/AdvancedSearch.aspx).

This literature review does not include information from the above list of nanoresearch databases. These databases could provide a starting point for future research.

2.2.4 Grant Databases

The following is a list of potentially-relevant research projects funded by EPA’s Science to Achieve Results (STAR) Grants in 2008:

y University of Delaware, Newark, DE. - Develop an understanding of the fate of manmade nanoparticles released into subsurface environments. Project will evaluate mobility of nanomaterials in soil and groundwater in a laboratory setting using batch experiments. Testing methods include dynamic light scattering and confical microscopy experiments. Goal is to evaluate current conceptual models. Contacts: Yan Jin and John Xiao.

y University of Michigan, Ann Arbor, MI - Provide fundamental information about the movement, fate and bioavailability of manmade, carbon nanotubes under different environmental conditions.

y Purdue University, West Lafayette, IN - Investigate how manmade nanomaterials change or transform under certain environmental conditions.

y Arizona State University, AZ - Evaluate biological treatment for removal of nanomaterials in wastewater treatment plants. The project will examine the fate of nanomaterials in wastewater treatment and drinking water treatment plants. The ASU researchers hope that this work will lead to methods for quantifying nanomaterials in water matrices and biosolids. Contact: Paul Westerhoff, Professor (Civil and Environmental Engineering). Paul Westerhoff was contacted under Search Strategy #3 (see Section 2.3).

Additional contacts may be identified from the above list of STAR grants for future research efforts (see Section 2.3). The following additional grant sources were also identified and may be reviewed to identify ongoing research in the field of sampling and analytical procedures for detecting nanomaterials:

y EPA’s National Center for Environmental Research (NCER) Nanotechnology Research Project (complete list available at http://es.epa.gov/ncer/nano/research/index.html); and

y National Nanotechnology Institute (NNI) Research Centers (http://www.nano.gov/html/centers/nnicenters.html).

2.3 List of Contacted Researchers

Table 2-5 lists the contacted researchers.

Table 2-5. List of Researchers Contacted

Last Name First Name Title/Office/Department Organization

Denison Richard Senior Scientist Environmental Defense

Special Assistant to the National Institute for Murashov Vladimir Director Occupational Safety and Health

Professor, NanoBioEarth, Hochella Michael Department of Geoscience Virginia Tech Englert Brian Carl Environmental Scientist EPA Office of Water

Professor, Department of Penn R. Lee Chemistry University of Minnesota Director of Molecular Environmental Technology, Materials and Process Simulation Center, Diallo Mamadou S. Beckman Institute Caltech Environmental Molecular Pacific Northwest National Baer Don Science Laboratory Laboratory

Professor, Department of Erickson Larry E. Chemical Engineering Kansas State University

Turco Ron ANE Project Coordinator Purdue University Professor, Department of Civil and Environmental Westerhoff Paul Engineering Arizona State University

2.4 Results of Literature Search and Potential Future Reviews

As a result of the information search strategy described in this section, the following information was obtained and evaluated for inclusion in this report:

y More than 500 titles identified by Dialog®; and y Approximately 60 published articles.

Table 2-6 presents the articles that were selected and reviewed in detail for this report and the general topic areas covered by each article. This list of articles includes articles that were identified by Dialog® and articles that were identified by the search of targeted literature sources and personal contacts. As shown in the table, little to no information was found for sediment, soil, and groundwater sampling and for differentiating

anthropogenic nanomaterials from natural nanomaterials. As a state-of-the-science review, this document is a “living” document and may benefit from additional research. Additional areas for future work include:

• Research additional currently-identified journal articles; • Research identified journals for additional articles; • Research identified conference proceedings; • Contact additional researchers; and • Focus areas of research on those in which the current review did not find substantial information.

Table 2-6. Articles Reviewed for Literature Search

Overview Transport Sampling Analysis Soil Soil Other Natural Natural Sediment Structure Structure Engineered Groundwater Groundwater Groundwater Surface Water Surface Water Surface Water Differentiation of of Differentiation Size Fractionation Chemical Analysis Direct Visualization Direct Visualization Mineral Phase/Internal Mineral Phase/Internal Anthropogenic Nanomaterials Nanomaterials Anthropogenic Article Citation Area Size Distribution/Surface Baer, D.R. et al. Characterization Challenges for Nanomaterials. Surface and Interface Analysis. 2008, 40: 529-537 X X X X Baalousha, M.; et al. Size-Based Speciation of Natural Colloidal Particles by Flow Field Flow Fractionation, Inductively Coupled Plasma-Mass Spectrometry, and Transmission Electron Microscopy/X-ray Energy Dispersive Spectroscopy: Colloids- Trace Element Interaction. Environmental Science & Technology 2006, 40, 2156-2162. X X X X X X Benoit, G.; Rozan, T. F. The influence of size distribution on the particle concentration effect and trace metal partitioning in rivers. Geochimica et Cosmochimica Acta 1999, 63, 113-127. X X X X X Bundshuh et al. Quantification of Aquatic Nano Particles after Different Steps of Bodensee Water Purification with Laser- induced Breakdown Detection (LIBD). Acta hydrochimica et hydrobiologica 2001, 29 (1), 7-15. X X Table 2-6. (Continued)

Overview Transport Sampling Analysis Soil Soil Other Natural Natural Sediment Structure Structure Engineered Groundwater Groundwater Groundwater Surface Water Surface Water Surface Water Differentiation of of Differentiation Size Fractionation Chemical Analysis Direct Visualization Direct Visualization Mineral Phase/Internal Mineral Phase/Internal Anthropogenic Nanomaterials Nanomaterials Anthropogenic Article Citation Area Size Distribution/Surface Burleson, D. J. et al. On the characterization of environmental nanoparticles. Journal of Environmental Science and Health Part A - Toxic/Hazardous Substances & Environmental Engineering 2004, 39 (10), 2707-2753. X X X X X X Chen, Zhou et al.. Quantification of C60 Fullerene Concentrations in Water. Environmental Toxicology and Chemistry. 2008, DOI: 10.1897/07-560.1 X X X Eggleston, C. Met al. The structure of hematite ([alpha]-Fe2O3) (001) surfaces in aqueous media: scanning tunneling microscopy and resonant tunneling calculations of coexisting O and Fe terminations. Geochimica et Cosmochimica Acta 2003, 67 (5), 985-1000. X X X X Essington, M. E. Soil and Water Chemistry: An Integrative Approach; CRC Press: Boca Raton, FL, 2004. X Fortner, J. D. et al. C60 in Water: Nanocrystal Formation and Microbial Response. Environmental Science & Technology 2005, 39 (11), 4307-4316. X X X X X Gilbert, B.et al. Stable cluster formation in aqueous suspensions of iron oxyhydroxide nanoparticles. Journal of Colloid and Interface Science 2007, 313, 152-159. X X X X X X Gimbert, L. J.et al. Partitioning and stability of engineered ZnO nanoparticles in soil suspensions using flow field-flow X X X X X

18 Table 2-6. (Continued)

Herrmann, A. M.e al.. Nano-scale secondary ion mass spectrometry - A new analytical tool in biogeochemistry and soil ecology: A review article. Soil Biology & Biochemistry 2007, 39 (8), 1835-1850. X Heymann, D.et al. Determination of C60 and C70 fullerenes in geologic materials by high-performance liquid chromatography. Journal of Chromatography A 1995, 689 (1), 157-163. X X X Hochella, M. F.; Madden, A. S. Earth's nano-compartment for toxic metals. Elements 2005, 1 (4), 199-203. X X Hwang, W. et al. Separation of Nanoparticles in Different Sizes and Compositions by Capillary Electrophoresis. Bulletin of the Korean Chemical Society 2003, 24 (5), 684-686. X Lead, J. R.et al. Trace metal sorption by natural particles and coarse colloids. Geochimica et Cosmochimica Acta 1999, 63, 1661-1670. X X X X X Li, X. Q. et al. Zero-valent iron nanoparticles for abatement of environmental pollutants: Materials and engineering aspects. Critical Reviews in Solid State and Materials Sciences 2006, 31 (4), 111-122. X X

19 Table 2-6. (Continued)

Overview Transport Sampling Analysis Soil Soil Other Natural Natural Sediment Structure Structure Engineered Groundwater Groundwater Groundwater Surface Water Surface Water Surface Water Differentiation of of Differentiation Size Fractionation Chemical Analysis Direct Visualization Direct Visualization Mineral Phase/Internal Mineral Phase/Internal Anthropogenic Nanomaterials Nanomaterials Anthropogenic Article Citation Area Size Distribution/Surface Lienemann, C. et al. Optimal preparation of water samples for the examination of colloidal material by transmission electron microscopy. Aquatic Microbial Ecology 1998, 14, 205-213. X X X X Lyven, B. et al.Competition between iron- and carbon-based colloidal carriers for trace metals in a freshwater assessed using flow field-flow fractionation coupled to ICPMS. Geochimica et Cosmochimica Acta 2003, 67, 3791-3802. X X X X X Madden, A. S.; Hochella, M. F. A test of geochemical reactivity as a function of mineral size: Manganese oxidation promoted by hematite nanoparticles. Geochimica et Cosmochimica Acta 2005, 69, 389-398. X X X X X Novak, J. P. et al. Purification of Molecularly Bridged Metal Nanoparticle Arrays by Centrifugation and Size Exclusion Chromatography. Analytical Chemistry 2001, 73 (23), 5758-5761. X Novikov, A. et al. Colloid Transport of Plutonium in the Far- Field of the Mayak Production Association, Russia. Science 2006, 314, 638-641. X X X X X X Saleh, N. et al. Adsorbed Triblock Copolymers Deliver Reactive Iron Nanoparticles to the Oil/Water Interface. Nano Letters 2005, 5 (12), 2489-2494. X X

20 Table 2-6. (Continued)

Overview Transport Sampling Analysis Soil Soil Other Natural Natural Sediment Structure Structure Engineered Groundwater Groundwater Groundwater Surface Water Surface Water Surface Water Differentiation of of Differentiation Size Fractionation Chemical Analysis Direct Visualization Direct Visualization Mineral Phase/Internal Mineral Phase/Internal Anthropogenic Nanomaterials Nanomaterials Anthropogenic Article Citation Area Size Distribution/Surface Stolpe, B et al. High resolution ICPMS as an on-line detector for flow field-flow fractionation; multi-element determination of colloidal size distributions in a natural water sample. Analytica Chimica Acta 2005, 535, 109-121. X X X X Tarassov, M. et al. Chemical composition and vibrational spectra of tungsten-bearing goethite and hematite from western rhodopes, Bulgaria. European Journal of Mineralogy 2002, 14, 977-986. X USEPA U.S. Environmental Protection Agency Nanotechnology White Paper;EPA 100/B-071/100; EPA Science Policy Council: Feb 1, 07. X Waychunas, G. et al. Nanoparticulate oxide minerals in soils and sediments: unique properties and contaminant scavenging mechanisms. Journal of Nanoparticle Research 2005, 7, 409-433. X X X X X Wigginton, N. S.; Haus, K. L.; Hochella, M. F. Aquatic environmental nanoparticles. Journal of Environmental Monitoring 2007, 9 (12), 1306-1316. X X X X X X Yuan, G. Environmental Nanomaterials: Occurrence, Syntheses, Characterization, Health Effect, and Potential Applications. Journal of Environmental Science and Health Part A - Toxic/Hazardous Substances & Environmental Engineering 2004, A39 (10), 2545-2548. X X

21 Table 2-6. (Continued)

3.0 BACKGROUND

This section describes natural and anthropogenic nanomaterials that may be present in the environment and the factors that affect their transport in various environmental media including surface water, groundwater, and soil. An analysis of nanomaterials in air is outside the scope or this review.

3.1 Overview of Nanomaterials

The U.S. National Nanotechnology Initiative defines nanomaterials as materials that measure 1 to 100 nanometers in at least one dimension. Nanomaterials exist naturally in the environment and also are intentionally and unintentionally produced from human activities. Section 3.1.1 presents an overview of the nanomaterials that may exist naturally in the environment, and Section 3.1.2 describes anthropogenic nanomaterials, both intentional and incidental, that are commonly produced.

3.1.1 Natural Nanomaterials

Several types of nanomaterials exist naturally and are produced by natural events such as chemical and physical weathering of rocks and minerals, combustion, volcanic eruptions, biomineralization, and precipitation reactions.1 For example, volcanic ash soils contain a nanodimensional aluminosilicate mineral, called imogolite, that has a hollow tubular particle morphology2. Natural inorganic nanoparticles, found in soils and geologic systems, can have atmospheric, geogenic or biogenic origin.3 Table 3-1 presents examples of naturally occurring nanomaterials and the mechanism of formation, and Table 3-2 lists minerals discussed in this report.

Table 3-1. Examples of Formation Processes for Natural Nanomaterials

Formation Process Type of Nanomaterial Examples Carbon-Containing Nanomaterials Biogenic Organic colloids Humic, Fulvic acids Organisms Viruses Geogenic Soot Fullerenes Atmospheric Aerosols Organic acids Pyrogenic Soot Carbon nanotubes, fullerenes Inorganic Nanomaterials Biogenic Oxides Magnetite Metals Silver, Gold Geogenic Oxides Iron oxide Clays Allophane Atmospheric Aerosols Sea salt Source: Nowack et al.3

Table 3-2. List of Minerals Used in Journal Articles Referenced in this Report4

Mineral Name Molecular Formula Description

Hematite α-Fe2O3 Iron oxide Goethite α-FeOOH Iron oxyhydroxide Ferrihydrite Fe5HO8•4H2O Iron hydrous oxide

3.1.2 Anthropogenic Nanomaterials

Anthropogenic nanomaterials are nanomaterials that are produced from human activity. They include both intentionally and unintentionally produced nanomaterials. Examples of unintentionally produced nanomaterials include diesel engine exhaust products and combustion process byproducts. The remainder of this subsection describes intentionally produced nanomaterials, including their applications and manufacturing processes.

Nanotechnology entails manipulating matter through chemical and/or physical processes to create materials with specific properties for use in particular applications. Size-dependant properties, such as catalytic, electrochemical, melting, magnetic, and optical properties, change when materials are reduced to the nanoscale. These unique characteristics make nanomaterials highly valuable for applications in commercial, medical, military, and environmental sectors.5

Nanomaterials in their unprocessed form are not marketable to consumers. The nanotechnology value chain is often described with three levels of nano-based products:

1. Nanomaterials: The first level includes the unprocessed nanomaterials, which serve as the building blocks for other products.

2. Nanointermediates: The second level includes intermediate products, called “nanointermediates” that incorporate nanomaterials or that have been designed with nanoscale features. Examples of nanointermediates include coatings, fabrics, catalysts, and computer chips.

3. Nano-enabled products: The third level includes nano-enabled products, which are finished goods that use nanomaterials or nanointermediates. Examples of nano-enabled products include clothing, sporting goods, pharmaceuticals, and medical devices.

As described previously, nanomaterials are materials that are nano-sized in at least one dimension. One-dimensional nanomaterials include thin films and surfaces and coatings, two-dimensional nanomaterials include nanotubes, nanowires, and nanofibers, and three-dimensional nanomaterials include fullerenes, quantum dots, and dendrimers.

3.1.2.1 Manufacturing Processes

Manufacturing processes to produce nanomaterials fall into one of two major categories:

y “Bottom-up” processes – These processes build nanoscale materials from individual atoms or molecules; and

y “Top-down” processes – These processes create nanoscale materials from their macro counterparts.

The bottom-up process, also called “molecular nanotechnology,” uses forces of nature to assemble nanomaterials atom by atom or molecule by molecule. The process can use chemical synthesis, self-assembly, or positional assembly. In general, bottom-up processes are less expensive than top-down processes.

The top-down process starts with a bulk material, and uses micro- or nano- lithography and etching to cut the bulk material into nanoscale structures. Processes include photolithography, electron beam lithography, and dip-pen lithography. The top- down processes are the dominant and most well-established manufacturing methods.

3.1.2.2 Nanomaterial Examples and Applications

Nanomaterial products are often characterized into four major categories:

y Carbon-based materials including carbon nanotubes and fullerenes;

y Metal-based materials including quantum dots, nanogold, nanosilver, and metal oxides;

y Dendrimers; and

y Composites.

Below is a more detailed description of these categories.

Carbon-based nanomaterials

Carbon-based nanomaterials include cylindrical shaped carbon nanotubes and spherical fullerenes. Carbon nanotubes are essentially graphite sheets that are rolled up into a tubular form. Nanotubes may be single-walled or multi-walled. An important property of carbon nanotubes is their high strength-to-weight ratio; carbon nanotubes are 100 times the strength of steel at a fraction of the weight. Carbon nanotubes also have unique electrical properties that allow them to be used for displays. Other applications of carbon nanotubes include computer chips, nanotools, and energy applications. For

example, carbon nanotubes can be attached to the tips of atomic force microscopes (AFM). Research shows that this practice can enhance the resolution for AFM and prevent damage to the sample surface and probe. In addition, carbon nanotubes may be used as safe hydrogen storage for hydrogen fuel cells.

Fullerenes are spherical cages of carbon atoms. One of the most well known is a fullerene composed of 60 carbon atoms, known as C60 fullerene or “buckyball”. Fullerenes have applications in drug delivery and in medical imaging as a contrast agent for MRIs. In addition, fullerenes have enhanced antioxidant properties that make them useful for antiaging cosmetics and pharmaceuticals. Similar to carbon nanotubes, fullerenes have unique electrical properties that can be used for power supplies, data storage devices, and solar cells. Researchers have also considered using fullerenes for hydrogen storage for hydrogen fuel cells.

Metal-based nanomaterials

Quantum dots are an example of metal-based nanomaterials. Quantum dots are closely packed semiconductor crystals composed of hundreds of thousands of atoms. These nanomaterials have unique optical properties that allow them to be used in applications such as biomedical imaging. Quantum dots adsorb light energy, which causes the energy levels of the electrons in the crystal structure to increase and release energy in the form of light. Unique to fluorescent light, quantum dots can emit light at different wavelengths depending on the size of the particle.

Materials for manufacturing quantum dots include semiconductors such as cadmium selenide, cadmium sulfide, cadmium telluride, lead sulfide, and lead telluride; metals such as gold, silver, nickel, and cobalt; and hybrid structures. The two primary manufacturing methods for quantum dots include a lithographic process that uses pressure to break down a thin semiconductor film into dots and a colloidal synthesis process. Quantum dots manufactured using the lithographic process have applications in telecommunications, logic circuits, and quantum computing. In the colloidal synthesis process, materials are dissolved in a polymer solvent. Chemical reaction causes the quantum dots to precipitate from solution. Manufacturers can control the size of the quantum dots by varying the reaction time. Quantum dots manufactured using the colloidal synthesis process can be used for biological and optics applications, such as light emitting diodes (LEDs) and tunable lasers.

Dendrimers

Dendrimers are three-dimensional nano-sized polymers composed of an inner core and branched units. Manufacturers use two methods to produce dendrimers:

y Divergent approach: This approach begins with the inner core and builds outward.

y Convergent approach: This approach begins with the outer branches and assembles them around the core.

Several modifications can be made to the dendrimer structure to alter its properties for specific applications. Modifications include filling the inner voids, modifying the dendrimer core, and modifying the dendrimer surface. Surface modifications can alter the particle’s charge and solubility, its ability to react with or bind to target entities, and its ability to pass through cell boundaries. The primary application of dendrimers is in drug delivery. However, because of their spherical shape, viscosity characteristics, and catalytic properties, dendrimers also have applications in coatings, additives, and inks.

Composites

Composites combine nanomaterials (such as nano clays) with other nanoparticles or bulk-type materials. Nanocomposites can enhance mechanical, thermal, barrier, and flame retardant properties for a wide range of products including auto parts and packaging materials.

3.2 Overview of Environmental Transport

The transport of nanoparticles in the environment requires extensive additional research because the transport mechanisms can depend on the environmental media, various environmental parameters, and various nanoparticle parameters. Nanoparticle parameters to consider can include particle size and charge, chemical or elemental composition, and surface modifications. Environmental media parameters to consider can include pH, ionic strength, flow rate, composition, and presence of naturally occurring (such as dissolved organic carbon) as well as anthropogenic contaminants and their interaction with nanoparticles. The following subsections summarize information collected that describes the transport of nanoparticles in surface water, soil, and groundwater. Each subsection identifies additional questions that are not addressed by the information reviewed to date.

3.2.1 Surface Water Transport

The colloidal stability and extent of aggregation of nanoparticles in water will greatly impact the transport potential of the nanoparticles. The colloidal stability can be a function of the pH and ionic strength of the water and the particular nanoparticle of interest.

With water samples, the dissolved fraction of the water has typically been operationally defined using filters. These operational definitions would define any material that can pass through the filter (e.g., a 0.2-μm filter (particles less than 200 nm)

or a 0.45-μm filter (particles less than 450 nm)) as the dissolved fraction, and material that does not pass through as the particulate fraction. However, the growing research on nanoparticles has shown that this notion will not always hold true3,6,7. The definition of a colloid as dispersed particles in the size range of 1 nm to 1 μm3,8 and suspended particles as particles greater than 1 μm in size can help demonstrate the role of nanoparticles in aquatic chemistry 8. Observations of colloidal material in aquatic systems demonstrate how nanoparticles may exist as nondissolved particles in water, thereby completely changing their transport potential.

Chemical and physical alterations can be applied to nanomaterials to increase their water solubility. For example, derivatization of hydrophobic C60 fullerenes with hydrophilic functional groups increases the solubility of the C60 nanomaterials. Sonicating C60 in organic solvents and water can form stable aqueous suspensions of fullerene aggregates denoted as nC60. C60 also has applications in personal care products 9 that contain organic ligands. These ligands can affect the aquatic transport of C60 .

Molecular solubility alone does not necessarily determine the water-based 10 availability of a nanomaterial. Fortner et al. show that C60 may form negatively charged water-stable colloidal aggregates with diameters from 50 to 500 nm. These colloids can have concentrations up to 100 mg/L (100 ppm), which is approximately 11 orders of 10 magnitude greater than the estimated molecular solubility of C60. Fortner et al. produce these aqueous colloidal suspensions by first producing a saturated solution of C60 in tetrahydrofuran (THF). The authors then add water to the THF solution under mixing and then evaporate the THF to form the aqueous C60 colloidal suspension. The authors note that adding an organic solvent, such as toluene, to the aqueous suspension results in low partitioning of nano-C60 from the water phase to the organic phase. However, the addition of an oxidant drives the nano-C60 to partition from the water phase to the organic phase. Therefore, the process of forming the aqueous suspension changes the properties 10 of the C60. Fortner et al. note that the water-stable nano-C60 aggregates are crystalline in nature, and the aggregates’ particle sizes are functions of mixing rate, pH, and ionic strength. The authors observe that lower mixing rates increase the particle size. Higher pH values produce smaller particles, while lower pH values produce larger particles. Higher ionic-strength solutions give rise to larger particles, and ionic strengths similar to that of seawater (~0.7 I) can cause particles to precipitate. On the other hand, lower ionic strengths, such as those similar to groundwater (~0.01 I), can lead to stable particles that can remain at concentrations of up to 100 ppm for at least 15 weeks. The researchers acknowledge that these fundamental laboratory experiments do not exactly predict what will occur if C60 is released into seawater or groundwater, as these experiments do not account for additional materials present in natural systems, such as proteins, humic acids, organic matter, and soils. This research does demonstrate, however, that important water properties can affect the extent of particle aggregation and lead to stable colloids or unstable precipitates, which can alter the transport of a nanomaterial.

Researchers at Arizona State University (ASU)11 are currently studying the fate of nanomaterials in wastewater treatment plants. The researchers have sampled at eight wastewater treatment plants and performed simulations of sequence batch reactors in a

laboratory setting to determine the portion of nanomaterials that partition to biomass. Unpublished findings of this research show that the partitioning of nanomaterials from water to biosolids ranges from 50 to 90 percent. ASU expects to publish its findings in May 200811.

Additional Questions

How do materials present in the natural environment, such as proteins, humic acids, organic matter, charged clay particles, and soils, impact the transport of nanomaterials in groundwater and seawater?

3.2.2 Soil Transport

Understanding the transport of nanoparticles in soil requires knowledge of the nanoparticles’ partitioning between the solid (soil) and liquid (water) phases. In general, the tendency for substances to partition from water to soil or sediment depends upon the hydrophobic characteristics of the substance and the properties of the solid media to which it will adsorb. In addition, partitioning can occur via covalent and ionic bond formation as well as through electrostatic adsorption. Surfactants, which are commonly used with engineered nanoparticles to aid in dispersions, might also affect the partitioning; therefore, the presence of a surfactant should be noted in a study to help fully inform the reader. For example, natural organic carbon (NOC) can act as a natural surfactant and researchers have found some evidence that NOC coatings can help stabilize some aqueous nanomaterial dispersions.

Gimbert et al.7 studied the partitioning of engineered ZnO nanoparticles in aqueous soil suspensions in the presence of sodium dodecyl sulfate (SDS) surfactant. The authors used SDS to ensure the ZnO nanoparticles dispersed in an aqueous solution as bare ZnO nanoparticles resisted dispersion in water. The authors first produced aqueous dispersions of ZnO in the presence of SDS and then used this dispersion to spike soil samples to target a final concentration of 1.2 percent mass Zn in soil. This high concentration of Zn (as ZnO) in soil was required to simulate a significant environmental exposure. They then incubated the soil samples at 60 percent moisture for 0, 7, and 14 days before analysis. The authors found that this ZnO dispersion quickly equilibrated between the solid and liquid phases and remained relatively stable for the 14-day period. The authors found little dissolution or increase in solid-phase partitioning during the 14- day period, indicating that the ZnO nanoparticles would persist in the environment. It should be noted that these results occurred in the presence of a surfactant.

12 Wang et al. studied the retention of nano-C60 aggregates in water-saturated porous media. The authors produce aqueous suspensions of C60 according to the methods discussed in Fortner at al.10 and summarized in Section 3.2.1 above: the authors begin with a saturated THF solution of C60, add water under mixing, and then remove the THF 12 to form the aqueous suspensions of nano-C60. Wang et al. study the retention of the nano-C60 aggregates in columns packed with either glass beads or Ottawa sand. The authors conduct the retention experiments with aqueous C60 suspensions prepared in

deionized water containing 1.0 mM CaCl2 buffered to a pH value of seven with 0.065 mM NaHCO3 and also with C60 suspensions prepared in deionized water alone. The authors find that, when using C60 suspensions with CaCl2 and NaHCO3 (ζ-potential of approximately -23.9 mV and ionic strength of approximately 3 mM), the glass beads retained from eight to 49 percent of the introduced mass of nano-C60, while the Ottawa sand retained up to 77 percent of the introduced mass of nano-C60. Additionally, the authors note that the retention of C60 was irreversible as the introduction of nano-C60-free deionized water did not elute the retained mass from the column. The Ottawa sand column had uniform nano-C60 retention, while the glass bead column had a nano-C60 retention that decreased with distance from the column inlet. This trend suggests that the nano-C60 retention in the Ottawa sand approached a limiting capacity. The authors note that using aqueous C60 suspensions prepared in deionized water alone (z-potential of approximately -64 mV and ionic strength of zero mM) showed no retention in either column packing. This observation demonstrates the importance of electrostatic interactions on the transport and retention of nano-C60 aggregates in both glass beads and Ottawa sand.

Additional Questions

Question 1: How readily do nanomaterials partition from liquid to solid phases in the absence of a surfactant or added surface functionality?

Question 2: How do soil properties affect transport of nanoparticles?

3.2.3 Groundwater Transport

The transport potential of nanoparticles in subsurface environments can depend upon several parameters, such as particle size, solution pH, ionic strength, soil composition, and groundwater flow velocity13. Groundwater typically has a higher ionic strength than rainfall but may have lower ionic strength than marine and many freshwater bodies. Higher ionic strengths can reduce the electrostatic repulsion among nanoparticles and increase aggregation. However, research has shown that surface modifications of nanoparticles can greatly alter their transport potential in environmental media. For example, many researchers are designing supports for zero-valent iron nanoparticles for the purpose of groundwater remediation. These supports create negatively charged and hydrophilic surfaces to aid electrostatic repulsion among nanoparticles and aquifer materials and reduce nanoparticle aggregation and aquifer material filtration13.

Saleh et al.14 design a zero-valent iron nanoparticle core with a protective, nonreactive magnetite shell (Fe3O4) to help remediate trichloroethylene from groundwater. They find that these nanoparticles rapidly flocculate and settle from solution in water. The authors show that modifying the nanoparticle with a novel triblock copolymer increases the electrophoretic mobility and suspension stability of the nanoparticle. The hydrophilic block of the triblock copolymer promotes electrostatic

repulsion from negatively charged surfaces (such as Fe and Mn oxides and natural organic matter) that naturally occur in near-neutral pH subsurfaces. Additionally, the triblock copolymer drives the adsorption of the nanoparticle to the nonaqueous phase liquid-water (NAPL-water) interface. This example shows how surface modifications of nanoparticles can greatly alter their transport potential in environmental media.

Additional Questions

Question 1: How readily do bare nanomaterials partition from liquid to solid phases in the absence of a surfactant or added surface functionality?

Question 2: How effective are aquifer materials at filtering bare nanomaterials in the absence of an added surface functionality?

4.0 SAMPLING TECHNIQUES

This section describes five research projects that involved collecting environmental samples for analysis of nanomaterials, including:

y One water sampling project; y Three sediment sampling projects; and y One soil sampling project.

Based on the information obtained, sampling techniques for nanomaterials in environmental media currently do not differ from established techniques for sampling environmental media.

Some issues regarding sampling remain whether one is sampling for nanomaterials or larger-sized materials. Sample representation is always a concern when sampling environmental media. One research scientist interviewed for this report stated that one should approach the issue of sample representation by visually inspecting a location for heterogeneity within the media. One should scale down the inspection from large to small spatial scales to identify areas of heterogeneity where sampling may be important15.

Another important concern with sampling is the risk of contamination. Although contamination is a concern for all types of sampling, nanomaterials may be more sensitive to contamination as they are likely to be present in very small quantities within the environmental media15.

One should also consider sample preservation and holding time as research shows that the structure and reactivity of nanomaterials can be time-dependant and change when exposed to different environments. Researchers of the Pacific Northwest National

Laboratory observe that the reactivity of nanomaterials in aqueous solutions changes dramatically over the course of one day16. Baer et al.17 describe two case studies that demonstrate the effects of time and environment on nanomaterials. In one study, the authors demonstrate the influence of particle environments on the nanoparticle chemistry by measuring differences in UV-visible transmission results for ceria nanoparticles before and after adding an oxidizing agent to the aqueous solution. In the second study, the authors demonstrate the time-dependent properties of iron nanoparticles by examining iron nanoparticles using transmission electron microscopy (TEM) before and after exposing the nanoparticles to deionized water for 24 hours. After 24 hours of exposure to deionized water, the oxide shell of the nanoparticle had thickened and was more porous and less ordered.17

Researchers acknowledge that a need exists for nanomaterial-specific sampling techniques. However, to date, developing sampling techniques has not been a high priority for nanomaterials research projects. Current priorities include determining how nanomaterials behave in the environment, identifying constituents of environmental concern, and developing analytical techniques11.

4.1 Sampling Techniques Suited for Surface Waters

One project was identified that involved sampling wastewater for nanomaterials. As described in Section 3.2.1, researchers at ASU and the United States Geologic Survey (USGS) collected samples at eight wastewater treatment facilities in August 2007. Sampling points included the final effluent from treatment and biosolids. The researchers analyzed the samples for fullerenes (C60) and micro-sized titanium dioxide (TiO2). The researchers hope that the approaches used for detecting micro-sized titanium dioxide can later be developed for nano-sizes. For analysis of fullerenes, aqueous samples underwent a solid-phase extraction, were concentrated into methanol, and were analyzed using liquid chromatography coupled with mass spectrometry (LC-MS). The biosolid samples were extracted into toluene, concentrated, and analyzed using LC-MS. The detection limit for fullerenes analysis was 500 ng/L. The extraction methods for aqueous and biosolids samples were validated using matrix spikes. For analysis of titanium dioxide, researchers used digression methods to show that TiO2 was present and used SEM to identify the microparticles11.

The researchers noted that the samplers in this work did not use any special protocols that were specific for nanomaterials. Developing sampling techniques is still in the early stages and was not the main focus of the project. Researchers are currently evaluating the need for certain protocols, such as “clean hands” sampling, and future sampling activities may implement these protocols11.

4.2 Sampling Techniques Suited for Sediments

Three projects were identified that involved sampling sediments for nanomaterials. These projects did not use sampling techniques or protocols that were

developed specifically for nanomaterials. The following discussion summarizes the sample collection and preparation techniques described for the three sediment sampling projects.

Hochella et al.18 demonstrate sampling riverbanks and riverbeds for further analysis of naturally occurring nanomaterials. The authors obtain samples by digging into the side of a riverbank and collecting riverbed mud from beneath a layer of sediment under the shallow stream edge.

To prepare samples for TEM analysis, the authors perform the following steps. They first air dry their sediment samples before storage. They then lightly grind the dry samples to make them more friable, which reduces the larger grain sizes and disperses the sample. The authors then use multiple stages of dry sieves at a cut-off size of 65 μm and then wet sieve in ethanol at 25 μm. They perform a final light grinding before preparing the TEM ultramicrotomed thin sections.

Hochella et al.19 sample bed sediment from the entrance of a mine for further analysis of natural nanoscale particles. The authors obtain the bed sediment from a small water channel and a small, shallow pond near the entrances of two mines. The authors sieve the wet sediment samples with 63-μm sieves using ambient water to prevent chemical changes from occurring. The authors note that sieving in this case helps to remove detrital material and allows for a uniform comparison between studies. The authors bottle and ice pack the samples for transport to the laboratory, where they centrifuge and dry the sediment samples. They gently mash the sediment samples to separate clots and note the importance of avoiding high-temperature drying to prevent mineralogical changes.

Heymann et al.20 obtain samples of geologic materials from the Cretaceous- Tertiary (K-T) boundary in New Zealand for further analysis of fullerenes. The authors crush and powder the samples and demineralize a portion of their samples using HCl and HF treatments. They then slurry the prepared solid samples with toluene and sonicate for several hours to extract fullerenes from the solid materials. The authors recover the toluene extraction for analysis of fullerenes.

4.3 Sampling Techniques Suited for Soil

One project was identified that involves the sampling soil for nanomaterials. Gimbert et al.7 obtain topsoil samples, which they air dry and sieve to 2 mm for performing nanomaterial transport studies. The authors did not describe any sampling techniques that were applied specifically for nanomaterials.

Additional Questions

Information found to date has been limited in this area. Additional research should be conducted in this area.

4.4 Sampling Techniques Suited for Groundwater

Information found to date has been limited in this area. Additional research should be conducted in this area.

4.5 Comparison of Sampling Techniques

Information regarding techniques for sampling nanomaterials found to date has been limited. The current literature search has not revealed well-defined sampling techniques specific to nanomaterials with outlined advantages and disadvantages. Additional research should be conducted in this area.

5.0 ANALYTICAL TECHNIQUES

This section identifies analytical techniques suited for characterizing naturally occurring nanomaterials and anthropogenic nanomaterials in natural media. Wigginton et al.21 identify the following characterization parameters applicable to characterizing nanomaterials in natural media:

• Size distribution; • Surface area; • Direct visualization; • Phase and structure; and • Chemical composition.

No single analytical technique provides information to address all five characterization parameters. Therefore, it is necessary to use combinations of analytical techniques to characterize nanomaterials. Additionally, nanomaterials in natural media may require size-fractionation techniques to separate the nanoparticles from larger particles. This section presents analytical techniques suited for fractionating and characterizing the five parameters of nanomaterials in natural media.

The ASTM Committee E-42 on Surface Analysis guides users of surface analytical instruments to produce more reliable results. The scope of the committee is to review and coordinate development of standards for all methods of surface analysis by photon, electron, and ion emissions or reflection methods, such as x-ray spectroscopy and secondary ion mass spectrometry (SIMS). A member of the ASTM Committee E-42 on Surface Analysis emphasizes the importance of proper sample handling and use of analytical instruments for analyzing nanomaterials. Because analytical instrumentation for characterizing nanomaterials are highly sensitive, a greater potential for error exists16.

Burleson et al.1 provide a technical review and description of many of the analytical techniques listed in Section 5.0. Section 5.7 includes general descriptions and

comparisons of many of the analytical techniques listed below. Below are brief descriptions of the major analytical techniques presented in this section.

Transmission Electron Microscopy (TEM)

TEM utilizes an electron beam to probe a sample and images the electrons that pass through the sample. TEM can provide a high-resolution direct image of the nanoparticles, typically greater than 0.1 nm of spatial resolution. Many TEMs can be operated in scanning transmission electron microscopy (STEM) mode1.

Scanning Electron Microscopy (SEM)

Energy-Dispersive Spectroscopy (EDS)

Electron Energy Loss Spectroscopy (EELS)

EELS measures primary signals from scattered electrons produced during TEM or STEM imaging for detecting and quantifying elements present in the sample1.

Atomic Force Microscopy (AFM)

AFM, a type of scanning probe microscopy (SPM), measures the forces between a sharp tip and a sample to determine topographic images at a spatial resolution of approximately 0.1 nm and provides electrical and mechanical properties of the sample1.

Scanning Tunneling Microscopy (STM)

STM, a type of scanning probe microscopy (SPM), measures a tunneling current between a conductive tip and a conductive or semiconductive sample to determine topographic images at a spatial resolution of approximately 0.1 nm and is sensitive to the chemical identity of surface atoms and molecules1.

X-ray Diffraction (XRD)

XRD measures the diffraction of X-ray beams to identify crystalline phases. XRD can measure structural properties of crystalline phases and probe atomic arrangements of amorphous phases1.

Dynamic Light Scattering (DLS)

DLS shines a light source on a suspension of particles and uses a photoelectric detector to measure the intensity of the scattered light. The constant Brownian motion of the particles causes time-dependant fluctuations, which are directly related to the diffusion coefficients of the particles. The diffusion coefficients allow the estimation of the hydrodynamic radius of the particles1.

Laser-Induced Breakdown Detection (LIBD)

LIBD uses an intense, pulsed laser beam to generate plasmas on nanoparticles. The generated plasmas emit light that is detected by the tool. The number of light emissions per number of laser pulses provides information on the concentration and sizes of particles in the sample22.

X-ray Absorption Spectroscopy (XAS)

XAS irradiates a sample with X-rays and measures the amount of X-ray energy the sample absorbs. X-ray energies that meet the electron-ejection threshold are absorbed and eject an electron. The ejected electrons are backscattered and produce interferences with the X-rays, which provide information on the average identity, number, and arrangement of the nearest neighboring atoms to the absorbing atom. This information allows researchers to identify the structure of the atoms in the sample1.

5.1 Analytical Techniques for Size Fractionation

Several fractionation techniques have the potential to separate particle samples into various nanoparticle fractions:

• Centrifugation – Centrifugation is a mechanical method that separates particles in a solution based on weight by applying a centrifugal force. Heavier particles sink outwardly while lighter particles rise towards the center of the vortex.

• Ultrafiltration – Ultrafiltration is a method that separates particles in solution based on molecular weight using a membrane barrier. Lower molecular weight particles permeate through the membrane while higher molecular weight particles remain in the retentate. The separation can be achieved by either direct-flow (perpendicular to the membrane) ultrafiltration or tangential-flow (cross-flow) ultrafiltration (TFF). The

benefit of TFF is the solution flows parallel to the membrane, which prevents buildup of particles at the membrane surface.

• Field-flow fractionation (FFF) – FFF separates particles by applying a perpendicular gradient or cross flow to a sample solution that is flowing through a narrow channel. The perpendicular gradient drives particles of different sizes toward the channel wall at different velocities.

• Capillary electrophoresis (CE) – CE separates particles based on their size to charge ratios. In this method, a buffer solution carries particles through a capillary typically from the anode to the cathode. When an electric charge is applied to the sample solution, the positively charged particles are attracted to the cathode while negatively charged particles are attracted to the anode. In addition to the particle charge, the particle’s size and shape determine the frictional forces that affect the particle’s transport through the buffer solution23.

• Size exclusion chromatography (SEC) – SEC separates particles based on size using the principle that particles of different sizes elute through a stationary phase at different velocities. A typical apparatus consists of a column packed with porous polymer beads. As the sample solution passes through the column, smaller particles will enter the pores. Therefore larger particles will elute faster.

These methods can apply for both aquatic colloids3 and particles extracted from soil and sediment samples7,19. All methods require nanoparticles to be in solution. Therefore, samples must be extracted into a solvent prior to analysis.

Aquatic Colloids

A typical and widely used method for fractionating colloids is TFF3,24. Benoit and Rozan25 use TFF to fractionate colloidal particles from river water samples using hollow-fiber filters with a 3,000 molecular weight cutoff. They note that the choice of a 3,000 molecular weight cutoff is arbitrary and, hence, their “colloidal” and “truly dissolved” materials are operationally defined. Lyven et al.24 note that natural aquatic colloids may exist in a dynamic state with respect to dissolved phase and particulate phase partitioning. Therefore, it is imperative that the fractionation technique involve mild and rapid pretreatment. They, therefore, recommend FFF as an appropriate fractionation technique for aquatic colloids. They recommend flow FFF (FlFFF) for smaller colloidal particles in the size range of 1 to 50 nm. FlFFF is a type of FFF that utilizes a cross flow to provide the perpendicular gradient used in the separation24. Researchers commonly use FlFFF with on-line detectors to measure particle concentrations. These techniques are typically spectral methods such as UV absorbance detectors24,26,27, fluorescence detectors (FLD)26, and multi-angle laser light scattering (MALLS)26.

FlFFF also allows the ease of coupling an on-line detector for chemical analysis, such as ICP-MS24,26,27. Stolpe et al.27 note that FlFFF and ICP-MS match well for coupling concerning operating flow rates and liquid phases. Additionally, band broadening from ICP-MS is not a significant issue as FlFFF peaks are already comparatively broad. Stolpe et al.27 also note that preconcentrating the sample may be necessary due to low elemental concentrations in natural waters and due to the large dilution of the sample during the FlFFF run. They note that preconcentration may introduce artifacts and use an on-channel preconcentration technique for their FlFFF runs27. Both TFF and FFF necessitate pretreatment to remove larger particles to prevent steric interferences and filter overloading24,25.

Several different authors filter their samples through a 0.45-μm filter before fractionation24-27, although settling is also an option24.

Lead et al.8 demonstrate the use of flow-through centrifugation of colloidal and suspended particulates from river water samples. They achieve three nominal size fractions of greater than 1.0 μm, 0.5 to 1.0 μm, and 0.05 to 0.5 μm. Their nominal size fractions are based on Stoke’s law and assume a particle density of 2.5 g/cm3. They note that these fractions represent lower limits due to organic matter entrained in the fractions and from applying Stoke’s law to generally nonspherical particles.

Lienemann et al.28 describe a method for using ultracentrifugation to deposit aquatic colloidal particles directly onto TEM grids for further analysis.

Soils and Sediments

Hochella et al.19 demonstrate the use of centrifugation to remove interstitial water from wet sediment samples. After centrifugation, they pour off the supernatant liquid leaving the solid sediment behind.

Gimbert et al.7 demonstrate a method of fractionating the sub-1.0-μm fraction of soil suspensions spiked with engineered ZnO nanoparticles using FlFFF. They couple FlFFF with a UV absorbance detector to characterize the particles and obtain fractograms. They find FlFFF to be successful in measuring the particle size distributions of the 180-nm nominally sized ZnO nanoparticles.

Engineered Nanoparticle Systems

Additional techniques used to separate engineered nanoparticles within an engineered system may prove applicable to separating nanoparticles within environmental media.

Hwang et al.23 use capillary electrophoresis (CE) to separate mixtures of gold and polystyrene nanoparticles of varying sizes. The authors first demonstrate the application of CE in separating gold nanoparticles of varying sizes and then in separating polystyrene nanoparticles of varying sizes. Lastly, the authors demonstrate the application of CE in

separating a mixture of gold and polystyrene nanoparticles of equal size. The authors use a UV-visible light absorbance detector to detect the separated particles and plot electropherograms. The electropherograms show the successful separation of the nanoparticles, and the authors note the potential application of CE to mixtures of other nanoparticles.

Novak et al.29 demonstrate using centrifugation and size exclusion chromatography to purify molecularly bridged gold nanoparticle arrays. The authors wish to separate dimers and trimers of the molecularly-bridged gold nanoparticles.

The authors note that centrifugation has the following drawbacks: 1) the nanoparticles may aggregate upon concentration, and 2) the nanoparticles may become unstable if combined with high ionic strength or nonaqueous solvents. The authors overcome aggregation by replacing one of the bridging ligands with another that would not cause particle aggregation. The authors perform stepwise g-force density centrifugation and collect highly viscous slurries of their modified molecularly-bridged gold nanoparticles29.

Novak et al.29 note that SEC has similar drawbacks as centrifugation. Additionally, SEC may also lead to the irreversible adsorption of the analytes to the stationary phase. The authors overcome this additional drawback by using an aqueous mobile phase containing sodium dodecyl sulfate (SDS) buffer. The authors couple SEC with a UV-visible light absorbance detector to detect the nanoparticles as a function of their column retention time and develop chromatograms. The authors note a high resolution of separation when separating pure gold nanoparticles of varying sizes but lower resolutions of separation when separating the dimer and trimer molecularly-bridged gold nanoparticles. The authors conclude that centrifugation is simpler and less expensive than SEC, but SEC has the potential for postcolumn analysis of optical and electrochemical properties of the analyzed nanoparticles.

5.2 Analytical Techniques for Size Distribution

Several analytical techniques are suitable for measuring size distribution of nanoparticles. The microscopy methods discussed in this section either use point count techniques that measure the sizes of individual particles or bulk analyses that measure the average and range of particle sizes in a sample, and include the following:

• Transmission Electron Microscopy (TEM) – TEM measures the size of individual particles by producing a high resolution (0.1 nm) two- dimensional image of the nanomaterial.

• Scanning Electron Microscopy (SEM) – SEM measures the size of individual particles by producing a topographical three-dimension image of the nanomaterial at resolutions ranging from 1 nm to 1 μm.

• Scanning Probe Microscopy (SPM) – SPM techniques determine the size of individual particles and include atomic force microscopy (AFM), which measures forces between a sharp tip and a sample to determine the topography of the sample, and scanning tunneling microscopy (STM), which measures a tunneling current between a conductive tip and a conductive or semiconductive sample to determine the topography of the sample.

• Dynamic Light Scattering (DLS) – DLS is a bulk analysis that measures the average particle size of dispersions or suspensions.

• Laser-Induced Breakdown Detection (LIBD) – LIBD is a bulk analysis that measures the average particle size and concentration of particles in the sample.

• Small- and Wide-Angle X-ray Scattering (SAXS/WAXS) – SAXS/WAXS is a bulk analysis that determines particle sizes and populations.

TEM

Many works cited in this report use TEM or a variation of it to obtain size distributions of nanoparticles along with shape and dimensional information10,18,19,30-33. Variations of TEM can include high-resolution (HR) TEM32,33 and cryogenic (cryo) TEM10.

Madden and Hochella30 and Madden et al.31 use TEM images, along with AFM images, to determine diameters and heights of synthesized hematite nanoparticles. The authors assign the nanoparticles by diameter into histogram bins with each bin assigned an average height. This method obtains a size distribution suitable for calculating surface area. See Section 5.3 for additional discussion.

Hochella et al.19 use TEM-EDS and EFTEM-EELS to characterize sediment samples. The authors are able to characterize 85-90 percent by volume of the TEM sections as containing ferrihydrite particles between 10 and 100 nm in diameter. The authors note that EFTEM-EELS obtains spatially resolved elemental distributions better than TEM-EDS.

SEM

SEM images may also be used to measure nanoparticle size distributions7,8,18,19. Lead et al.8 demonstrate the use of SEM to verify the discrete size fractionation of aquatic nanoparticles from centrifugation. The authors note that most particles sampled are less than 1 μm in size with some particles as large as 10 μm or 100 μm in at least one dimension.

Hochella et al.19 use SEM in conjunction with TEM to gain an additional perspective on the sediment samples. The authors note that SEM does not capture the complex nature of the particles as well as TEM.

SPM

Madden and Hochella30 and Madden et al.31 use AFM images, along with TEM images, to determine diameters and heights of synthesized hematite nanoparticles. The authors assign the nanoparticles by diameter into histogram bins with each bin assigned an average height. This method obtains a size distribution suitable for calculating surface area. See Section 5.3 for additional discussion.

Eggleston et al.34 use STM images of hematite nanoparticles in both air and aqueous media to obtain dimensional measurements. They additionally use the resonant tunneling model (RTM) to help interpret the STM images. They find RTM to qualitatively agree with many features of the STM images.

DLS

Waychunas et al.32, Gilbert et al.33, Fortner et al.10, and Zhang et al.35 demonstrate the use of dynamic light scattering (DLS) to measure average size distributions of 32,33 10 nanoparticle dispersions and suspensions of iron oxyhydroxide , C60 fullerene , and CdTe quantum dots35. Further, Gilbert et al.33 use DLS to measure average size distributions as a function of pH, and Waychunas et al.32 use DLS to measure average size distributions as function of suspension aging. Both of these works use DLS to help characterize nanoparticle aggregation and understand the factors that can lead to aggregation.

LIBD

Bundschuh et al.22 demonstrate the use of LIBD to quantify colloids in the effluents of various treatment stages in a drinking water treatment plant. LIBD is a sensitive analytical tool capable of quantifying low concentrations (< 1 μg/L) nanoparticles smaller than 100nm. The method uses an intense, pulsed laser beam to generate plasmas on colloidal particles. The generation of plasmas is called a “breakdown event.” The plasmas generated by the breakdown event emit light or generate shock waves that are detected by the tool. In general, solids require less energy to break down than liquids or gases. LIBD is based on the difference in breakdown thresholds of liquid and solid matter. The laser beam energy is set to exceed the solid breakdown threshold but not the liquid threshold. The number of breakdown events per number of laser pulses depends on the concentration and size of the particle.

A charged coupled device (CCD) camera detects the light emissions of single plasmas to determine the particle size. Detection of optical spatially resolved plasma light emissions results in a spatial distribution of breakdown events within the focal volume. Spatial distribution depends on the particle size. The authors compare the

distribution to the distribution width of reference particles to determine the mean particle diameter. They then calculate the mean particle diameter and breakdown probability22.

SAXS/WAXS

Waychunas et al.32 demonstrate the use of small- and wide-angle X-ray scattering (SAXS/WAXS) to determine the size distribution and population of goethite nanoparticles as a function of time. The authors make in situ measurements and note that these particular nanoparticles aggregate in solution as they age. The authors additionally use SAXS/WAXS to make ex situ measurements on samples they measured using other techniques. The authors present graphical processed SAXS results that demonstrate the aging particle size distributions over time.

Gilbert et al.33 use SAXS to study the colloidal stability of iron oxyhydroxide nanoparticles as a function of pH and ionic strength over time. The authors make in situ measurements and note slight nanoparticle aggregation after 10 weeks but no macroscopic aggregation even after four months at pH values less than 6.6. The authors note a greater extent of aggregation at pH values greater than 6.6.

5.3 Analytical Techniques for Surface Area

The average surface area of nanoparticles is a useful characterization parameter. Average surface area may be calculated in conjunction with size distribution or may be calculated directly using the Brunauer-Emmett-Teller method (BET). The BET method utilizes a gas, typically nitrogen, to adsorb to the accessible surface area of a sample. The adsorbed gas forms a monolayer of molecules or atoms along the accessible surface area. One may then measure the volume of the adsorbed monolayer of gas and, with knowledge of the size of the gas molecules or atoms and the mass of the sample, calculate the surface area per mass of the sample1.

Madden and Hochella30 and Madden et al.31 discuss methods for calculating the surface area of synthesized hematite nanoparticles using measurements from TEM and AFM and the particles’ nanocrystalline geometries. The authors use two-dimensional TEM images to determine two-dimensional length and width measurements and use AFM to determine height measurements. Madden and Hochella30 note that, in this particular work, particle diameters measured from AFM are larger than diameters measured from TEM due to tip-sample interaction, although heights measured from AFM are accurate. Therefore, they use TEM-measured diameters and AFM-measured heights. The particles are arranged by diameter into histogram bins with each bin assigned an average AFM-measured height. Knowing the nanocrystalline geometry of the particles, the authors then calculate the average surface area of the individual particles for each bin. The authors calculate the total surface area for all particles by converting the average surface area per particle to surface area per mass for each bin and calculate the weighted sum of all surface areas.

It is important to note that the above method for calculating surface area may not be applicable to nanomaterials that do not have a regular or pseudo-regular geometry or have significant porosity.

Madden and Hochella30, Madden et al.31, Waychunas et al.32, and Gilbert et al.33 use BET to directly measure the surface area of nanoparticles. Madden and Hochella30 also note that surface areas for ultrafine particles, less than 15 nm in diameter, are typically lower from BET measurements than those calculated from geometric models as described above.

5.4 Analytical Techniques for Direct Visualization

Direct visualization can produce a direct visual representation or image of individual nanoparticles from a small sample. Visualization allows one to examine geometry and shape characteristics of the observed nanoparticles. Techniques for direct visualization include:

• Electron microscopy techniques, such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM); and, • Scanning probe microscopy (SPM), such as atomic force microscopy (AFM) and scanning tunneling microscopy (STM).

Electron Microscopy

A widely used electron microscopy technique is TEM, which is an indispensable tool and is often a staple for nanomaterial researchers1,36.

A number of cited papers in this report use TEM to obtain images of individual nanoparticles10,18,19,28,30,31. Other variations of TEM include high-resolution (HR) TEM1,32,33 and scanning transmission electron microscopy (STEM)1,26. Coupling TEM with EELS can produce energy-filtered (EF) images with spatial resolutions on the order of 0.5 nm1. Hochella et al.19 find better spatially resolved information about elemental distributions from EFTEM-EELS images. Fortner et al.10 even use cryogenic (cryo) TEM, which uses a cryogenic sample holder to allow the imaging of flash-frozen samples. See Section 5.7 for a discussion and comparison of these different variations of TEM.

Additionally, HRTEM images may show morphological characteristics of nanoparticles. Waychunas et al.32 use HRTEM images to determine morphological changes of goethite nanoparticles in suspension from initial oblong shapes to rod-like shapes caused by oriented aggregation during aging. The images show rod-shaped particles with dimensions of approximately 10 x 100 nm after 33 days of aging.

A number of cited papers in this report additionally use SEM to obtain images of individual nanoparticles7,8,18,19. Lead et al.8 are even able to visually identify the presence of bacteria in their SEM images. Hochella et al.18 additionally capture

backscattered electron (BSE) images to locate grains of sediment samples containing heavy metals. Hochella et al.19 use SEM in conjunction with TEM to gain an additional perspective on the sediment samples. The authors note that SEM does not capture the complex nature of the particles as well as TEM. See Section 5.7 for a discussion and comparison of these different variations of SEM.

Scanning Probe Microscopy

A number of cited papers in this report use AFM to image individual nanoparticles30,31,34. Madden and Hochella30 and Madden et al.31 mainly use AFM to obtain heights of the sampled nanoparticles.

Additionally, Eggleston et al.34 use STM to image hematite nanoparticles in both air and aqueous media. They additionally use the resonant tunneling model (RTM) to help interpret the STM images. They find RTM to qualitatively agree with many features of the STM images.

5.5 Analytical Techniques for Phase and Structure

The structure of nanoparticles may be crystalline or amorphous. Knowledge of the structure of naturally occurring crystalline nanoparticles along with chemical information may determine the identity of the mineral phase of the nanoparticle. Techniques that provide information on nanoparticle structure include electron diffraction, X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), and Raman spectroscopy.

Electron Diffraction

When using TEM, one may measure the diffraction of electrons passing through the sample to obtain the crystal structure of crystalline materials. Hence, electron diffraction can differentiate between amorphous and crystalline materials. Additionally, information from electron diffraction and TEM images can determine size and size distribution of crystalline nanoparticles. Variations of electron diffraction include selected-area electron diffraction (SAED) and convergent beam electron diffraction (CBED)1.

Madden and Hochella30 use electron diffraction to confirm the identity of their synthesized hematite nanoparticles as judged by the mineral’s structure.

10 Fortner et al. use SAED to confirm the crystalline structure of C60 nanoparticles. The SAED diffraction patterns from a single particle show a simple hexagonal unit cell structure.

X-ray Absorption Spectroscopy

XAS irradiates a sample with X-rays and measures the amount of X-ray energy the sample absorbs. X-ray energies that meet the electron-ejection threshold are absorbed and eject an electron. The ejected electrons are backscattered and produce interferences with the X-rays, which provide information on the average identity, number, and arrangement of the nearest neighboring atoms to the absorbing atom. From this information, the structure of the atoms in the sample may be obtained1.

Waychunas et al.32 are able to use Extended X-ray Absorption Fine Structure (EXAFS) measurements to determine that their goethite nanoparticles increase in structural ordering during the aging process of their studies.

X-ray Diffraction

XRD measures the diffraction of X-ray beams to identify crystalline phases. When compared to a database of known diffraction patterns, it can quantitatively identify mineral composition. For example, Hochella et al.18 use XRD with the computer program RockJock to quantitatively determine the mineralogical composition of riverbank and riverbed samples. RockJock compares the intensities of the diffraction patterns to that of an internal standard: ZnO.

Hochella et al.19 use XRD to determine the presence of mineral phases, such as quartz and jarosite, in their acid mine drainage samples.

Madden et al.31 use XRD to confirm the structural characteristics of their synthesized nanoparticles are consistent with hematite.

Waychunas et al.32 use XRD to confirm their synthesized iron oxyhydroxide nanoparticles are initially goethite and remain as such throughout the aging process of their studies.

Gilbert et al.33 use XRD to determine that the crystal phase of their synthesized iron oxyhydroxide nanoparticles is consistent with a nanoscale and highly disordered goethite phase.

Raman Spectroscopy

Tarassov et al.37 use micro-Raman spectroscopy to study the atomic arrangement of hematite and goethite microparticles sampled from the oxidation zone of the Grantcharitza scheelite deposit in Bulgaria. The authors compare the Raman spectra of their samples against spectra from reference particles. This analysis enables the authors to determine that the local atomic structure of the sampled hematite particles deviate from reference hematite. The Raman spectra reveal that the sampled hematite has a disordered structure.

5.6 Analytical Techniques for Chemical Analysis

Chemical analytical techniques either are suitable for a bulk analysis or capable of obtaining spatial resolutions. Bulk chemical analytical techniques do not directly identify the presence of nanoparticles, nor do they provide appropriate information to characterize them. They do, however, directly identify and possibly quantify the presence of atoms, functional groups, or molecules. These chemical analytical techniques allow one to identify the atomic or molecular components of nanoparticles. Chemical analytical techniques capable of obtaining spatial resolutions can identify and spatially map elements. These chemical analytical techniques allow for greater surface characterization of the sample. This section presents information obtained on sample extraction techniques, bulk chemical analyses, and chemical analyses with spatial resolution.

An important step in bulk chemical analysis is sample extraction and preparation. Sample extraction techniques directly impact the method detection limit. Chen et al.9 evaluate three techniques for extracting nC60 fullerene from aqueous samples for HPLC/MS analysis:

y Technique 1 – Evaporation of aqueous phase followed by partitioning of dry fullerenes into toluene

y Technique 2 – Liquid-liquid extraction with addition of salts; and

y Technique 3 – Solid phase extraction (SPE) of aqueous sample using preconditioned SPE cartridges followed by toluene extraction to remove fullerenes from the cartridges.

The addition of salts for Technique 2 improved recovery of C60 compared to Technique 1. However, the authors found Technique 3 to be the most effective of the three methods in C60 extraction. The SPE method can be automated and can handle larger volumes of sample than Techniques 1 and 2, resulting in less time required for analysis, lower detection limits, and reduced potential for error. The authors conclude that SPE is applicable for extracting nanoparticles that exist in aqueous environments as discrete or aggregated forms, and can also be used for analysis of biological or soil samples. The sample extraction techniques directly impacted the method detection limit for the analysis as shown in Table 5-1.

Table 5-1. Determination of Method Detection Limit for the Measurement of Stable 9 Aqueous C60 Aggregates in Ultrapure Water

Technique MDL (μg/L) Technique 1 – Evaporation 2.78 Technique 2 – Liquid-liquid extraction 3.33 Technique 3 – Solid phase extraction 0.30

Bulk Chemical Analysis

General analytical techniques suitable for bulk chemical analysis include atomic absorption spectrometry (AAS), atomic emission spectrometry (AES), and mass spectrometry (MS). These methods are used to identify the elements present in a sample and can quantify the average elemental composition of a sample. Excitation sources include flame, graphite furnace (GF) and inductively-coupled plasma (ICP). These bulk elemental analytical techniques have several advantages: 1) they are relatively easy to perform and relatively inexpensive, 2) they have relatively good detection limits, and 3) they provide an average composition of a sample of nanoparticles. These methods also have several disadvantages: 1) they are destructive techniques (i.e. one may not recover the sample after analysis), 2) sample preparation and matrix effects can introduce major contaminants, and 3) they are limited to providing only an average composition of the sample of nanoparticles and cannot correlate chemical composition to spatial location1.

Benoit and Rozan25 demonstrate a method of extracting particulates from river water samples for elemental analysis by GFAAS. They also chelate dissolved metals for elemental analysis by GFAAS. The authors use ICP-AES for elements that were at higher concentrations. Zhang et al.35 use GFAAS to measure the cadmium concentration of water suspensions of CdTe quantum dots. The authors are able to derive the quantum dot core concentrations from the cadmium concentrations.

Baalousha et al.26, Lyven et al.24, and Stolpe et al.27 demonstrate coupling ICP- MS online with FlFFF. Stolpe et al.27 note that FlFFF and ICP-MS match well for coupling concerning operating flow rates and liquid phases. Additionally, band broadening from ICP-MS is not a significant issue as FlFFF peaks are already comparatively broad.

Stolpe et al.27 additionally note that they choose to use high-resolution ICP-MS (HR-ICP-MS) over quadrupole ICP-MS. The authors note that, when compared to quadrupole-ICP-MS, HR-ICP-MS offers a higher resolving power, higher sensitivity, and lower background noise; hence, it increases the numbers of elements capable of detection and lowers the detection limits. However, using a magnetic-sector MS design to obtain high resolution images requires a longer time to change magnetic fields; thus, scanning large mass ranges of elements may increase the time for analysis27.

Table 5-2 presents results from Lyven et al.24 demonstrating the detection limit and actual measured concentration of various elements identified in their aquatic samples using ICP-MS.

Benoit and Rozan25 and Lyven et al.24 use high temperature catalytic oxidation to quantify organic carbon. Lyven et al.24 note they could not reliably quantify the ICP-MS carbon signal.

10 13 Fortner et al. use C-NMR to analyze suspensions of nano-C60 in D2O. They 13 enrich the C60 with C at 25 percent.

20 Heymann et al. quantify the naturally occurring C60 and C70 fullerenes in various geologic samples. They demonstrate a method for using HPLC to separate C60 and C70 fullerenes from the organic material associated with the geologic samples coupled with UV-visible light absorption spectroscopy to quantify the fullerenes at their respective retention times. The authors discuss the importance of sample preparation and prior knowledge of the nanomaterials sought after. They cite that fullerenes are vulnerable to ultraviolet radiation, heating in air, and exposure to ozone and, as such, avoid strong irradiation and heating above 60oC of the samples. They note that HPLC is nondestructive, which allows the recovery of the sampled fullerenes.

Fortner et al.10 also use HPLC with UV-visible absorption spectroscopy to compare the retention time of C60 fullerenes that were recovered from an aqueous phase to an organic phase with C60 fullerenes in an organic phase that did not contact an aqueous phase initially. Chen et al.9 evaluate UV/vis spectroscopy for analyzing aqueous nC60 fullerenes. The authors established a linear relationship between UV absorbance and the concentration of nC60 in standard water samples. The authors determined that the detection limit of 0.3 mg/L was higher than expected environmental concentrations and concluded that UV spectrophotometry is not a selective or sensitive method to quantify C60 fullerene in aqueous environmental samples.

Table 5-2. ICP-MS Detection Limits and Ratio of Measured Concentration to Detection Limit from Freshwater Samples as Provided by Lyven et al.24

Ratio of Measured Isotope Detection Concentration to Element (m/z) Limit (nmol/L) Detection Limit C 12 Not Quantified 144a Mg 26 7.7 21 Al 27 11 47 Ca 44 23 91 Mn 55 0.1 31 Fe 57 14 1000 Co 59 0.02 13 Ni 60 0.2 36 Cu 65 1.5 9 Zn 66 0.9 11 Sr 88 0.005 44 Y 89 10 66 Zr 90 1 3 Mo 95 0.1 7 Sb 121 0.1 5 Ba 137 0.3 28 La 139 0.06 111 Ce 140 0.2 41 Pr 141 0.06 34 Nd 147 0.07 18 Gd 157 0.04 17 Dy 162 0.04 23 Pb 208 0.05 52 Th 232 0.03 26 U 238 0.03 18 a Estimated using 10 times the standard deviation of the baseline and the fractionated creek sample.

Chemical Analysis with Spatial Resolution

X-ray spectroscopy, commonly referred to as energy-dispersive spectroscopy (EDS), X-ray energy-dispersive spectroscopy (XEDS), or energy-dispersive X-ray spectroscopy (EDX), measures secondary signals from characteristic X-rays produced during TEM, STEM, or SEM imaging for detecting and quantifying elements present in the sample. EDS is relatively easy to use in conjunction with TEM, STEM, or SEM and can obtain a spatial resolution on the order of 0.5 nm for elemental mapping1.

Electron Energy Loss Spectroscopy (EELS) measure primary signals from scattered electrons produced during TEM or STEM imaging for detecting and

quantifying elements present in the sample. EELS has an increased energy resolution over EDS, which allows it to obtain additional information on chemical bonding, oxidation state, and average bond distances. EELS also can achieve a greater spatial resolution for elemental mapping, although the resolution is still on the order of 0.5 nm1.

Hochella et al.18 use TEM-EDS and SEM-EDS to analyze riverbank and riverbed samples. Hochella et al.19 use TEM-EDS and EFTEM-EELS to characterize acid mine drainage sediment samples. The authors note that EFTEM-EELS obtains spatially resolved elemental distributions better than TEM-EDS. The authors additionally use SEM-EDS, which obtains a poorer spatial resolution of elements than TEM-EDS and TEM-EELS. Hochella et al.19 note that TEM-EDS and EFTEM-EELS added significant details to the understanding of their acid mine drainage samples that SEM-EDS and XRD alone would not have revealed.

Baalousha et al.26 use STEM-EDS to determine surface elemental chemical maps of river colloidal particles. The authors use the surface elemental maps to verify the chemical compositions determined from FlFFF coupled with ICP-MS. The authors note their STEM-EDS results are semiquantitative.

Nanoscale secondary ion mass spectrometry (NanoSIMS) is a high-resolution microscopic technique capable of isotopic analysis. A primary ion beam, such as Cs+ or O-, is rastered across the surface of the sample causing it to sputter and eject secondary ions from the sample. The ejected secondary ions are separated by their mass-to-charge ratios for detection and isotope identification. NanoSIMS may simultaneously identify up to five to seven species, depending on the model. The raster-scanning process can map the surface isotopes and may achieve a lateral resolution of 50 nm. In addition to surface information, NanoSIMS may also provide depth information. Static NanoSIMS can provide information within the first nanometer of depth from the sample surface, while dynamic NanoSIMS may achieve depths within a few nanometers from the sample surface. Herrmann et al. note that time-of-flight secondary ion mass spectrometry (ToF- SIMS) may also provide molecular and isotopic surface information, but not while simultaneously providing high mass resolution and high spatial resolution with adequate signal transmission. NanoSIMS can provide high mass and spatial resolutions with excellent signal transmission38.

Herrmann et al.38 provide several considerations for using NanoSIMS. The analyzed sample should be dry, stable, conductive, and able to withstand the ultra-high vacuum of NanoSIMS. Soil samples should be flat and highly polished to avoid charging effects. Additionally, the use of a gold coating and an electron gun may reduce charging effects. Aqueous and in vivo samples may not be analyzed with NanoSIMS. Proper sample preparation is required. Freeze drying samples may cause ice crystal damage. Embedding the sample in an epoxy resin is a suitable sample preparation method. Sulphur embedding is also possible, although it is limited to small samples and has a short time frame of consistency. Samples should be less than 4 mm thick to avoid outgassing issues. Analyzing soil samples may prove semiquantitative and the use of standards may prove difficult. NanoSIMS has a field of view ranging from 5 to 50 μm.

Precisely aligning the sample where the NanoSIMS analysis is to occur may prove challenging due to the restricted field of view. Optical microscopy may assist in navigating the sample. Additionally, because NanoSIMS is a destructive technique, one may not further analyze the same sample.

Novikov et al.39 use NanoSIMS to analyze the elemental composition, particularly plutonium and uranium, of groundwater colloidal samples. NanoSIMS provides elemental maps of the colloidal particles.

5.7 Comparison of Analytical Techniques

This section describes the major analytical techniques presented and summarizes the advantages and disadvantages of each of the above described analytical techniques for each of the covered areas of characterization (e.g., size fractionation, size distribution). Advantages and disadvantages of the analytical techniques may include ease of use, potential resolution, and data interpretation.

Spectroscopies for Electron Microscopy

Electron Energy Loss Spectroscopy (EELS) measures primary signals from scattered electrons produced during TEM or STEM imaging for detecting and quantifying elements present in the sample. EELS has an increased energy resolution over EDS, which allows it to obtain additional information on chemical bonding, oxidation state, and average bond distances. EELS also can achieve a greater spatial resolution for elemental mapping, although the resolution is still on the order of 0.5 nm1.

Transmission Electron Microscopy (TEM)

TEM utilizes an electron beam to probe a sample and images the electrons that pass through the sample. TEM offers several advantages for characterizing nanoparticles. TEM is typically coupled with EDS or EELS for chemical analysis. TEM can provide a high-resolution direct image of the nanoparticles, typically greater than 0.1 nm of spatial resolution. TEM can also use electron diffraction, such as SAED or CBED, to distinguish between crystalline and amorphous phases. Additionally, TEM can determine the size and size distribution of crystalline nanoparticles1.

However, TEM also carries several disadvantages. Only a small fraction of nanoparticles sampled are examined, which makes it difficult to ensure that a representative sample is examined1 (10,000 images should be examined to ensure

statistical validity1). TEM produces a two-dimensional image of a three-dimensional object, which requires proper interpretation of the image. TEM operates near vacuum, which requires an ex situ analyzing environment. Sample preparation can introduce substantial artifacts, such as aggregate fragmentation, precipitation of salts, or nanoparticle aggregation1.

Hochella et al.19 note the difficulty in preparing heterogeneous precipitates, which might be sensitive to vacuum and beam exposure, while assuring an unbiased sampling of particles. The authors choose a method of embedding the samples in epoxy resin and cutting cross-sections using a diamond-knife ultramicrotome. This method allows unbiased sampling and uses encapsulation to stabilize delicate phases19.

TEM can be operated at high resolution (HRTEM), which is capable of spatial resolutions on the order of 0.1 nm. Energy-filtered TEM (EFTEM), coupled with EELS, may produce energy-filtered images with spatial resolutions on the order of 0.5 nm. Many TEMs can be operated in scanning transmission electron microscopy (STEM) mode. STEM provides superior resolution (<0.1 nm spatial resolution) and can still be coupled with EDS or EELS. It can also be coupled with high-angle annular dark field (HAADF) to produce “Z-contrast” images. A Z-contrast image directly relates image contrast with atomic weight of the imaged atoms. Environmental TEM (ETEM) allows the characterization of nanoparticles in a controlled atmosphere up to several torr of pressure. It can even allow the characterization of nanoparticles while reacting with gases to provide more of an in situ characterization1. Despite its disadvantages, TEM still remains a staple in characterizing environmental nanoparticles due to its many advantages36.

Scanning Electron Microscopy (SEM)

Like TEM, SEM also utilizes an electron beam to probe a sample. However, SEM primarily measures the secondary electrons (SE) emitted from the sample to produce topographical contrast maps. SEM does not provide the same high resolution TEM provides: its resolution is limited to approximately 1 nm to 1μm. Like TEM, SEM can also be coupled with EDS for chemical analysis. SEM requires less sample preparation than TEM, but SEM still maintains the concern for proper sample representation. Unlike TEM, SEM does provide reliable three-dimensional topographic imaging. SEM can also reduce any hydrocarbons present in the sample, which can deposit a layer of carbonaceous material on the imaged area and reduce image contrast. The high-vacuum environment can be detrimental to samples with volatile components. Inadequately coated samples can lead to charging, which can lead to image distortion, artifacts, or sudden discharges. The electron beam itself can damage or alter samples1.

SEM offers the option of capturing backscattered electron (BSE) signals and measuring their diffraction through the sample to obtain crystallographic and texture information. Additionally, BSE intensities can yield atomic number contrast maps. Environmental SEM (ESEM) allows the characterization of nanoparticles in a controlled

atmosphere in the range of 1 to 10 torr. However, ESEM can only provide a maximum spatial resolution of three to four nanometers1.

Scanning Probe Microscopy (SPM)

Atomic Force Microscopy (AFM), a type of scanning probe microscopy (SPM), measures the forces between a sharp tip and a sample to determine topographic images at a spatial resolution of approximately 0.1 nm and provide electrical and mechanical properties of the sample. Unlike electron microscopies, AFM offers in situ characterization and characterization of nonconducting samples, can characterize surfaces undergoing reaction, provides sub-nanometer spatial and vertical resolution, and possesses an inherent surface sensitivity1.

Disadvantages of AFM include a lack of direct information on chemical composition, tip limitations, potential tip and sample damage, potential displacement of nanoparticles, and data interpretation1.

Another type of SPM is scanning tunneling microscopy (STM), which measures a tunneling current between a conductive tip and a conductive or semiconductive sample. STM is capable of achieving molecular- to atomic-scale resolution. STM is also sensitive to the chemical identity of the surface atoms and molecules1.

X-ray Diffraction (XRD)

X-ray diffraction (XRD) measures the diffraction of X-ray beams to identify crystalline phases. XRD can measure structural properties of crystalline phases and probe atomic arrangements of amorphous phases. By comparison to a database of known diffraction patterns and use of a computer program such as RockJock, XRD can quantitatively identify the mineralogical composition of samples such as quartz or feldspar1,18. XRD can determine average particle size of crystalline materials below approximately 50 nm. However, XRD cannot directly identify elements present in the sample1.

The advantages of XRD include the following: it allows for quick identification of crystalline materials, it distinguishes between crystalline and amorphous materials, it produces additive patterns, it is quick and relatively inexpensive, it obtains particle size and size distribution of crystalline particles, and it can analyze samples in controlled atmosphere chambers1.

The disadvantages include the following: trace components (less than approximately one mass percent) can be difficult to detect, the technology cannot directly identify elements, XRD patterns are an average over all particles in the sample, and peak shapes can be difficult to interpret1.

Dynamic Light Scattering (DLS)

Dynamic light scattering (DLS) shines a light source on a suspension of particles and uses a photoelectric detector to measure the intensity of the scattered light. The constant Brownian motion of the particles causes time-dependant fluctuations, which are directly related to the diffusion coefficients of the particles. The diffusion coefficients allow the estimation of the hydrodynamic radius of the particles1.

DLS allows for in situ and real-time analysis of particle size and aggregation of suspensions of nanoparticles. A particle suspension with a concentration that is too high or too low or with particles with strong interparticle interactions may lead to inaccurate particle size determinations1.

Laser-Induced Breakdown Detection (LIBD)

Laser-Induced Breakdown Detection (LIBD) uses an intense, pulsed laser beam to breakdown colloidal particles and generates plasmas. The generated plasmas emit light back to the CCD camera. The CCD detects light emissions of single plasmas to determine particle size. In addition, detection of optical spatially resolved plasma light provides the spatial distribution of breakdown events within the focal volume. LIBD allows particles within a sample to be quantified. However, this method does not distinguish between or identify individual compounds. The tool can detect colloids as small as 2 nm in diameter and at concentrations as low as 1.6 ng/L.

The authors applied this technique in analyzing drinking water samples. The ability of this method to apply to environmental samples containing higher concentrations of suspended solids is not known based on information reviewed for this report. In addition, the method application is specific to analysis of colloids and assumes that particle shape is spherical. LIBD uses reference particles to determine the sizes of the sample particles. Therefore the method assumes that the particles in the sample have comparable properties, adsorption coefficients, dielectric properties, and ionization energies to the reference particles22.

X-ray Absorption Spectroscopy (XAS)

X-ray absorption spectroscopy (XAS) irradiates a sample with X-rays and measures the amount of X-ray energy the sample absorbs. X-ray energies that meet the electron-ejection threshold are absorbed and eject an electron. The ejected electrons are backscattered and produce interferences with the X-rays, which provide information on the average identity, number, and arrangement of the nearest neighboring atoms to the absorbing atom. From this information, the structure of the atoms in the sample may be obtained1.

XAS can provide detailed structural information and may be useful for semicrystalline and amorphous nanoparticles. This utility of XAS is important when compared to XRD, which is suited for primarily for crystalline nanoparticles. XAS

allows for the following advantages: in situ experimentation as high vacuum is not required, the possibility of distinguishing between surface and bulk chemical species, the identification of elements and their oxidation states, characterization of the degree of order of the particles, and determination of atomic arrangement, measurements of surface sensitivity. However, XAS has the following disadvantages: the required use of synchrotron radiation, complicated data interpretation, and an overall average of all the particles for all results1.

6.0 DIFFERENTIATION OF ANTHROPOGENIC NANOMATERIALS

A literature search to date has not revealed peer-reviewed documents concerning the differentiation of anthropogenic and natural nanomaterials. Conversations with researchers have revealed that differentiating anthropogenic and natural nanomaterials can prove difficult, especially when the anthropogenic nanomaterial is released into environmental media15. It is helpful to compare the sampled nanomaterial to a known sample of an engineered nanomaterial to look for similarities as a control. However, it is also important to note that an engineered nanomaterial may undergo changes upon entering into the environment.

Some anthropogenic nanomaterials do not occur naturally. Therefore, analyzing the composition of a sampled nanomaterial from environmental media may provide information as to the origin of the nanomaterial. For example, CdSe does not occur naturally and, if discovered in the environment, one can assume its original source is most likely anthropogenic15.

The current difficulties with differentiating anthropogenic and natural nanomaterials have led to the idea of isotopic enrichment of engineered nanomaterials for ultimate tracking purposes. Isotopic enrichment could serve as a marker that would essentially barcode engineered nanomaterials to identify them with their specific source. Researchers have indicated that currently this would prove to be economically infeasible; therefore, this technology is not being used15.

7.0 SUMMARY

The approach to this review included three separate strategies:

y Collection of available published literature using Dialog®;

y Review of information from targeted sources, such as nano- specific journals, conference proceedings, grants databases, and research databases; and

y Contacts with industry and academic experts.

The review also identifies several sources that provided information on analytical techniques and equipment for nanomaterials. However, little information was obtained for sampling techniques that are specific for analysis of nanomaterials. Information obtained indicated that nanomaterial-specific sampling techniques have not yet been developed. Another area for which the search results provided little information is for differentiating anthropogenic (man-made) nanomaterials from natural nanomaterials. A number of potential sources that may provide additional information upon a more in- depth review were identified. As this report provides a current state-of-the-science review of active research topics at the time of writing, this report may require modifications as additional research is conducted.

8.0 REFERENCES

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Purification with Laser-induced Breakdown Detection (LIBD). Acta hydrochimica et hydrobiologica 2001, 29 (1), 7-15.

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60 Appendix A

DIALOG SEARCH RESULTS

A-1: POTENTIALLY RELEVANT TITLES FOR SAMPLING AND ANALYSIS OF NANOMATERIAL

A-2: POTENTIALLY RELEVANT TITLES FOR ENVIRONMENTAL REMEDIATION USING NANOMATERIALS

A-3: IRRELEVANT TITLES Appendix A-1

POTENTIALLY RELEVANT TITLES FOR SAMPLING AND ANALYSIS OF NANOMATERIAL Table A-1. Titles Pertaining to Sampling and Characterization of Nanomaterials in the Environment

Type of Number of Database Title Date Source References Number Other Information Conference: International surface A Review of Viable Monitoring Techniques for Conference engineering congress - 1 Nanoparticle Exposure Assessments Aug-05 Proceedings unknown 65 4th (200508) Adsorption characteristics of a nanodiamond for oxoacid anions and their application to the selective 2 preconcentration of tungstate in water samples Mar-03 Article 37 34 Amphiphilic polyelectrolytes: Characterization of associative properties and self-assembled 3 nanostructures in water 2006 Article 91 34 An air quality study of nanomaterials in a 4 manufacturing setting 2007 Article unknown 35 An environmental transmission electron microscope for in situ synthesis and characterization of 5 nanomaterials Jul-05 Article 75 34 Analysis of environmental particles by atomic force microscopy, scanning and transmission electron 6* microscopy 2004 Article unknown 41 7 Analyzing air nanoparticulates 27-Feb-06 Article unknown 34 Application of high-angle annular dark field scanning transmission electron microscopy, scanning transmission electron microscopy-energy dispersive X-ray spectrometry, and energy-filtered transmission electron microscopy to the characterization of 8 nanoparticles in the environment 15-Feb-03 Article 33 34 Table A-1. (Continued)

Type of Number of Database Title Date Source References Number Other Information Conference: Institut fur Festkorperforschung; Soft matters complex materials on mesoscopic scale - Conference Winter school; 33rd 9 Birth and Fate of Nanoparticles in Water Mar-03 Proceedings unknown 65 (200203) Carbon-60 nanoparticles: Adsorption and desorption 10 of organic contaminants and transport in soil 2006 Article unknown 35 Characterization of representative ambient air ultrafine and nanoparticulate matter in the El Paso- Juarez metroplex: Morphology, chemical 11 compositions, and speciation (Texas Mexico) 2003 Article unknown 35 Colloidal transport and agglomeration in column studies for advanced run-off filtration facilities - Particle size and time resolved monitoring of 12* effluents with flow-field-flow-fractionation 2004 Article unknown 41 Concentrations of nano and related ambient air 13 pollutants at a traffic sampling site Nov-05 Article 51 34 Cytotoxicity assessment of some carbon nanotubes and related carbon nanoparticle aggregates and the implications for anthropogenic carbon nanotube 14 aggregates in the environment 1-May-05 Article unknown 73 Developmental toxicity in zebrafish (Danio rerio) embryos after exposure to manufactured nanomaterials: Buckminsterfullerene aggregates (nC 15 SUB 60) and fullerol 1-May-07 Article unknown 73 Book Title: Nano and Micro Particles in Dynamic digital image analysis: Emerging Water and Wastewater 16* technology for particle characterization 2004 Book unknown 76 Treatment Table A-1. (Continued)

Type of Number of Database Title Date Source References Number Other Information Book Title: Nano and Micro Particles in Electron-optical characterization of nano- and micro- Water and Wastewater 17* particles in raw and treated waters: An overview 2004 Book unknown 76 Treatment Environmental nanomaterials: Occurrence, syntheses, characterization, health effect, and 18* potential applications Sep-04 Article 19 34 Establishing environmentally benign manufacturing 19 protocol at the high rate nanomanufacturing center. 3-Mar-05 Article unknown 34 Evaluation of the toroid cavity detector for electrophoretic NMR: NMR diffusion, relaxation and spectroscopic studies of monolayer protected 20 water soluble gold nanoclusters 2001 Article unknown 35 Exposure and characterization of nano-structured hole arrays in tapered photonic crystal fibers using a 21 combined FIB/SEM technique 31-Oct-05 Article 21 34 Fate and Transport of Nanomaterials in Drinking 22* Water 2007 Article unknown 245 Conference: NSTI Nanotech the Nanotechnology conference and trade Fate, Transport and Toxicity of Nanomaterials in Conference show - Conference; 23 Drinking Water May-07 Proceedings unknown 65 Nanotechnology Conference: NSTI Nanotech the Nanotechnology conference and trade Forensic Environmental Analysis of Nanotechnology Conference show - Conference; 24 Regulation May-07 Proceedings unknown 65 Nanotechnology Table A-1. (Continued)

Type of Number of Database Title Date Source References Number Other Information Health and environmental impact of nanotechnology: Toxicological assessment of manufactured 25 nanoparticles Jan-04 Article 11 34 Identification and characterization of potential sources of worker exposure to carbon nanofibers 26 during polymer composite laboratory operations 2007 Article 12 34 Interferometric optical detection and tracking of very 27* small gold nanoparticles at a water-glass interface 9-Jan-06 Article 21 34 Ion beam analysis of urban aerosol micro and nanoparticles compared with environmentally related 28 children diseases in two Polish towns 30-May-05 Article 6 34 Magneto-optical investigations of nanostructured materials based on single-molecule magnets monitor 29 strong environmental effects 19-Nov-07 Article 61 34 Measurement of cluster ions and residue nanoparticles from water samples with an 30 electrospray/differential mobility analyzer Jun-06 Article 47 34 Conference: NSTI Nanotech the Nanotechnology Methods for the Prediction of Nanoparticle Fate, conference and trade Transport and Receptor Exposure in an Aqueous Conference show - Conference; 31 Environment May-07 Proceedings unknown 65 Nanotechnology Book Title: Nano and Micro Particles in Water and Wastewater 32 Monitoring floc formation and breakage 2004 Book unknown 76 Treatment Mott-Schottky and charge-transport analysis of 33 nanoporous titanium dioxide films in air 29-Mar-07 Article 40 34 Multi-criteria decision analysis and environmental 34 risk assessment for nanomaterials Aug-07 Article 24 34 Table A-1. (Continued)

Type of Number of Database Title Date Source References Number Other Information Nano-C-60 fullerene particles and naphthalene 35 adsorption-desorption and transport in soil 28-Aug-05 Article unknown 34 American Chemical Society. Division of Nano-C SUB 6 SUB 0 fullerene particles and Environmental naphthalene adsorption -desorption and Conference Chemistry Meeting - 36 transport in soil Aug-05 Proceedings unknown 65 230th Nanomaterials in water environments: Potential applications, treatments, fate and potential biological 37 consequences 28-Aug-05 Article unknown 34 Nano-scale secondary ion mass spectrometry - A new analytical tool in biogeochemistry and 38* soil ecology: A review article Aug-07 Article 139 34 39 Nanotechnology -monitoring exposure. Oct-06 Article unknown 317 National Science Foundation funds research into 40 environmental fate of nanoparticles. 1-Sep-04 Article unknown 9 Word Count: 226 On the characterization of environmental 41 nanoparticles Sep-04 Article 173 34 Optical characterization of ultrasmall, hydrogen- terminated and carboxyl-functionalized silicon 42 nanoparticles in aqueous environments 2006 Article unknown 35 Conference: Nanocomposites and nanoporus materials; ISNAM7 - International Preparation and Characterization of Environmental- Conference symposium; 7th ( 43 Friendly Epoxy Resins/Clay Nanocomposites Feb-06 Proceedings unknown 65 200602 ) Table A-1. (Continued)

Type of Number of Database Title Date Source References Number Other Information Preparation, purification, characterization, and cytotoxicity assessment of water-soluble, transition- 44 metal-free carbon nanotube aggregates 2006 Article 36 34 Principles for characterizing the potential human health effects from exposure to nanomaterials: 45 Elements of a screening strategy 6-Oct-05 Article unknown 73 Quantification of aquatic nano particles after different steps of Bodensee water purification with 46* laser-induced breakdown detection (LIBD) Jul-01 Article 24 34 Quantitative analysis of polycyclic aromatic hydrocarbons in water in the low-nanogram per litre range with two-step laser mass 47 spectrometry 2003 Article unknown 31 Issue Title: Size distribution and characterization of ultrafine Environmental 48 particles in roadside atmosphere 1-Sep-04 Article unknown 73 Nanomaterials Solid-state water-mediated transport reduction of 49 nanostructured iron oxides Feb-01 Article 20 34 The obtaining and characterization of nanocrystalline NaCl dispersions for "saline" type therapeutical environments. II. The in situ analysis of saline rooms 50 aerosols Oct-04 Article 4 34 This little nano went to market ... eventually: the industry, government, and academia first have to tackle nanotechnology's manufacturing design, 51 safety, and environmental issues. 29-Jun-06 Article unknown 9 Word Count: 1235 Time gated detection of europium nanoparticles in a 52 microchannel based environmental immunoassay 2004 Article unknown 95 Table A-1. (Continued)

Type of Number of Database Title Date Source References Number Other Information Conference: Time-gated detection of europium nanoparticles in a BioMEMS and microchannel-based environmental immunoassay Conference nanotechnology - 53* (5275-47) Dec-03 Proceedings unknown 65 Conference ( 200312 ) Title: RBS characterization of nanometric ZrN/TiN and ZrNC/TiNC multilayers used as reflectors for X- 54 ray water window 1-Jul-05 Article unknown 103 Ultrafine nanoparticles--inhalation exposure, 55 characterization and assessment. 2007 Article unknown 317 Use of NMR spectroscopy in the synthesis and characterization of air- and water-stable silicon 56* nanoparticles from porous silicon 31-May-05 Article 36 34 Water solubilization, determination of the number of different types of single-wall carbon nanotubes and their partial separation with respect to diameters by 57* complexation with eta-cyclodextrin 2003 Article 26 34 Water-soluble GdF3 and GdF3/LaF3 nanoparticles- physical characterization and NMR relaxation 58* properties 16-May-06 Article 34 34 *Article identified as “article of interest” and evaluated for inclusion in report. Appendix A-2

POTENTIALLY RELEVANT TITLES FOR ENVIRONMENTAL REMEDIATION USING NANOMATERIALS

Table A-2. Titles Pertaining to the Use of Nanomaterials for Environmental Remediation

Number of Type of Keyword Database Title Date Source References Number Other Information Conference: Fine, ultrafine and 6-D Reactive Nanoparticles as Destructive Adsorbents: nano particles, new technologies, from Environmental Remediation to Military Conference emerging applications and new 1 Decontamination Oct-00 Proceedings unknown 65 markets - Conference ( 200010 ) Application of Iron Nanoparticles for Groundwater 2 Remediation Spring 06 Article unknown 40 BLOCK COPOLYMER SURFACE MODIFIERS TO ENABLE NEW GROUNDWATER REMEDIATION TECHNOLOGIES BASED ON NANOSCALE ZERO 3 VALENT IRON PARTICLES 2007 Article unknown 293 Conference: Experimental and Characterization of Environmental Degradation Conference applied mechanics - Annual 4 Mechanisms in Epoxy -clay Nanocomposites Jun-06 Proceedings unknown 65 conference ( 200606 ) 5 Contaminants removal from water using nanoparticles 2006 Article unknown 35 Decomposition of toxic environmental contaminants by 6 recyclable catalytic, superparamagnetic nanoparticles 9-May-07 Article 49 34 Dendritic nanoparticles: Synthesis, characterization and 7 environmental applications Mar-03 Article unknown 34 Discussion of nano-scale iron for dehalogenation by Evan K. Nyer and David B. Vance (2001), Ground Water Monitoring & Remediation, v. 21, no. 2, pages 41- 8 54 Jan-02 Article 6 34 Electrochemically Fabircated Zero-Valent Iron, Iron- Nickel, and Iron-Palladium Nanowires for 9 Environmental Remediation Applications 2007 Article unknown 40 Encapsulation of multi-Walled carbon nanotubes (MWCNTs) in Ba super(2+)-alginate to form coated micro-beads and their application to the preconcentration/elimination of dibenzo-p-dioxin, 10 dibenzofuran, and biphenyl from contaminated water 2004 Article unknown 76 Table A-2. (Continued)

Number of Type of Keyword Database Title Date Source References Number Other Information Encapsulation of multi-walled carbon nanotubes (MWCNTs) in Ba2+-alginate to form coated micro- beads and their application to the preconcentration/elimination of dibenzo-p-dioxin, 11 dibenzofuran, and biphenyl from contaminated water 2004 Article 13 34 12 Engineered polymeric nanoparticles for soil remediation 1-Mar-04 Article 38 34 Engineering palladium-on-gold bimetallic nanoparticles 13 as groundwater remediation catalysts 2006 Article unknown 35 Environmental catalysis using nano-sized bimetallic 14 particles: Selenium remediation 2005 Article unknown 35 Fate, transport, and environmental availability of copper(II) applied in catfish aquaculture ponds and enhanced immobilization of soil-bound lead using a new 15 class of stabilized iron phosphate nanoparticles 2007 Article unknown 35 Green synthesis of carbon-supported nanoscale iron 16 particles for in situ environmental remediation 26-Mar-06 Article unknown 34 17 GROUNDWATER: Nanoparticles Clean Contaminants. Oct-03 Article unknown 636 Word Count: 652 Conference: Water Environment Federation WEFTEC 06 - 79th: ANNUAL TECHNICAL H.E.N.C.I. Technology and the Advent of High-Flowrate Conference EXHIBITION AND 18 Cost- Effective Nanocatalytic Groundwater Remediation Oct-06 Proceedings unknown 65 CONFERENCE ( 200610 ) Injection of nanocrystalline titanium dioxide into porous media for uranium contaminated groundwater 19 remediation 2007 Article unknown 35 Inorganic nanoparticles synthesized from biological 20 precursors for environmental remediation 2005 Article unknown 35 Iron-iron oxide core shell nanoparticles for contaminant 21 underground water treatment May-05 Article 3 34 Membrane-based bimetallic nanoparticles for environmental remediation: Synthesis and reactive 22 properties Dec-05 Article 28 34 Table A-2. (Continued)

Number of Type of Keyword Database Title Date Source References Number Other Information Mesoporous nanocrystalline magnesium oxide for 23 environmental remediation 1-Nov-07 Article 36 34 Conference: ASAE/CSAE, ASAE/CSAE 2004 annual Conference international meeting - Annual 24 Modeling of Soil Remediation by Nanoscale Particles Aug-04 Proceedings unknown 65 international meeting ( 200408 ) Nanobiotechnology for enzymatic remediation and soil 25 carbon sequestration. 13-Mar-05 Article unknown 34 Nano-biotechnology in using enzymes for environmental 26 remediation Mar-03 Article unknown 34 Nanocomposite permeable reactive barriers: "Green" 27 nanotech for environmental remediation 26-Mar-06 Article unknown 34 28 Nanomaterials for environmental remediation 28-Aug-05 Article unknown 34 Nanoparticle and nanoporous carbon adsorbents for 29 removal of trace organic contaminants from water Oct-05 Article 32 34 Nanoscale iron particles for environmental remediation : 30 An overview Aug-03 Article 20 34 31 Nanoscience opportunities in environmental remediation Aug-03 Article 68 34 Nanostructured materials for environmental remediation 32 of organic contaminants in water Sep-04 Article 153 34 Nanostructures in environmental pollution detection, 33 monitoring, and remediation Jan-07 Article 42 34 Nanotechnology and Groundwater Remediation: A Step 34 Forward in Technology Understanding Spring 06 Article unknown 40 35 Nanotechnology for environmental remediation. Jun-05 Article unknown 317 36 Nanotreating contaminated soil Jun-04 Article unknown 34 Novel photocatalytic nanocomposite systems based on 37 anatase TiO2 for environmental remediation. 13-Mar-05 Article unknown 34 Photocatalytic degradation of organic contaminants in 38 water by ZnO nanoparticles: Revisited 10-May-06 Article 20 34 Polymeric nanoparticles for soil remediation of 39 hydrophobic contaminants 28-Aug-05 Article unknown 34 Table A-2. (Continued)

Number of Type of Keyword Database Title Date Source References Number Other Information Preparation and characterization of a new class of starch- stabilized bimetallic nanoparticles for degradation of 40 chlorinated hydrocarbons in water 1-May-05 Article 34 34 Original Title: Herstellung und Eigenschaften einer neuen Klasse, mit Staerke stabilisierter Bimetall- Preparation and characterization of a new class of starch- Nanoteilchen fuer den Abbau stabilized bimetallic nanoparticles for degradation of chlorierter Kohlenwasserstoffe in 41 chlorinated hydrocarbons in water 3-Nov-05 Article unknown 315 waessriger Loesung Preparation of a layered titanoniobic acid-alumina nanocomposite and its potential applicability to removal 42 of organic contaminants in water Mar-04 Article 32 34 Reactivity and lifetime of nano-scale zero-valent iron for groundwater dense non-aqueous phase liquid 43 remediation 28-Jun-05 Article unknown 35 Reduction of halogenated groundwater contaminants by 44 nano-sized magnetite May-05 Article unknown 34 Remediation of soil contaminated with pyrene using 45 ground nanoscale zero-valent iron Feb-07 Article 19 34 Removal of humic acid by coagulation with nano-Al Book Title: Particle Separation 46 sub(13) 2006 Book unknown 41 2005 - Drinking Water Treatment Removal of organic contaminants from water using 47 nanosponge cyclodextrin polyurethanes Apr-07 Article 24 34 Semiconductor nanostructures for detection and degradation of low level organic contaminants form 48 water. Mar-03 Article unknown 34 Stability of nanoiron slurries and their transport in the 49 subsurface environment 1-Dec-07 Article 38 34 Stabilization of Fe-Pd nanoparticles with sodium carboxymethyl cellulose for enhanced transport and dechlorination of trichloroethylene in soil and 50 groundwater 3-Jan-07 Article 41 34 Table A-2. (Continued)

Number of Type of Keyword Database Title Date Source References Number Other Information Supported Bimetallic Zerovalent Metal Nanoparticles in Conference: Electrochemical the Remediation of Chlorinated Organic Contaminated Conference Society ECS - Meeting abstracts, 51 Water May-07 Proceedings unknown 65 211th ( 2007 May ) Synthesis of nanostructured pristine and doped titanium 52 dioxide for oxidizing contaminants in air. 13-Mar-05 Article unknown 34 Tailoring the surface of metallic nanoparticles for 53 environmental remediation. 28-Mar-04 Article unknown 34 tEmulsified nanoscale iron particles for environmental 54 remediation of heavy metals 26-Mar-06 Article unknown 34 Conference: Synthesis, functional The Characterization and Reactivity of Nanostructured properties and applications of Cerium-Copper-Oxide Composites for Environmental Conference nanostructures - Symposium ( 55 Catalysis Apr-01 Proceedings unknown 65 200104 ) The synthesis and characterization of nanostructured titanium dioxide photocatalysts and their performance in 56 selected environmental and industrial applications 2001 Article unknown 35 Title: Nano-Biotechnology in Using Enzymes for Environmental Remediation: Single-Enzyme 57 Nanoparticles 1-Jan-05 Article unknown 103 Title: Nano-science opportunities in environmental 58 remediation 1-Oct-03 Article unknown 103 Treatment of pentachlorophenol-contaminated soil using 59 nano-scale zero-valent iron with hydrogen peroxide 16-Mar-07 Article 16 34 Using nanoscale zero-valent iron for the remediation of 60 polycyclic aromatic hydrocarbons contaminated soil Aug-05 Article 30 34 Zero-valent metal nanoparticles for soil and groundwater 61 remediation. 22-Aug-04 Article unknown 34

Appendix A-3

IRRELEVANT TITLES

23/6/1 (Item 1 from file: 6) Fulltext available through: Check for PDF Download Availability and Purchase

2335782 NTIS Accession Number: PB2006-100537/XAB Industry Consortium Analysis of Large Reverse Osmosis/ Nanofiltration Element Diameters. Desalination and Water Purification Research and Development Report No. 114 ( Final rept. (October 2003-September 2004) ) Sep 2004

23/6/2 (Item 2 from file: 6) Fulltext available through: Check for PDF Download Availability and Purchase

2312658 NTIS Accession Number: PB2005-103807/XAB Field Evaluation of Nanofilm Detectors for Measuring Acidic Particles in Indoor and Outdoor Air ( Research rept. Oct 98-Jan 02 ) Sep 2004

23/6/3 (Item 3 from file: 6) Fulltext available through: Check for PDF Download Availability and Purchase

2250027 NTIS Accession Number: N20020076301/XAB Radiation Exposure Effects and Shielding Analysis of Carbon Nanotube Materials ( Final Report, 1 Jul. - 31 Dec. 2001 ) Aug 2002

23/6/4 (Item 4 from file: 6) Fulltext available through: Check for PDF Download Availability and Purchase

2219298 NTIS Accession Number: PB2002-100293/XAB Evaluation of the Port Hueneme Demonstration Plant: An Analysis of 1 MGD Reverse Osmosis, Nanofiltration and Electrodialysis Reversal Plants Run under Essentially Identical Conditions. Desalination and Water Purification Research and Development Program Report No. 65

May 2001

23/6/5 (Item 1 from file: 9)

04187228 Supplier Number: 159976556 (USE FORMAT 7 OR 9 FOR FULLTEXT) NanoSensors Reports Preliminary Marketing Assessment of First Product.

February 27, 2007

Word Count: 539

23/6/6 (Item 2 from file: 9)

04111649 Supplier Number: 153516050 (USE FORMAT 7 OR 9 FOR FULLTEXT) Do nanofibers improve filter performance? Coalescing filters separate small liquid droplets from gas streams or from another liquid phase. Extensive modeling gives an optimum answer.

October 2006 Word Count: 1525

23/6/8 (Item 4 from file: 9)

03760175 Supplier Number: 135766104 (USE FORMAT 7 OR 9 FOR FULLTEXT) From confusion to action: whether your company is like traditional manufacturer Air Products and Chemicals or 20-year old Nanofilm Ltd., the first step in formulating a strategy for capitalizing on nanotechnology is understanding parameters.

September 2005 Word Count: 2017

23/6/9 (Item 5 from file: 9)

03452485 Supplier Number: 122824297 Nano Bisaisui Air Freshener MANUFACTURER: Matsushita Electrics CATEGORY: 416 - Deodorizers & Air Fresheners.

September 06, 2004 Word Count: 33

23/6/11 (Item 7 from file: 9)

02978050 Supplier Number: 98731506 Nano Mineral 71 Mist Lotion Toilet Water MANUFACTURER: Doctor Mineral CATEGORY: 311 - Skin Care.

January 20, 2003 Word Count: 111

23/6/12 (Item 8 from file: 9)

02670678 Supplier Number: 25155247 (USE FORMAT 7 OR 9 FOR FULLTEXT) Nano-scale detection biosensor for environmentally harmful substances. (Biosensors)

March 2002 Word Count: 254

23/6/13 (Item 1 from file: 31)

00594459 WSCA Abstract Number: 07-01230 WSCA ID Number: 641230 Application of Raman spectroscopy and sequential injection analysis for hydrogen ion concentration (pH) measurements with water dispersion of polyaniline nanoparticles.

2007

23/6/14 (Item 2 from file: 31)

00593729 WSCA Abstract Number: 07-00500 WSCA ID Number: 640500 Spectrometric determination of trace arsenic in water samples using a nanoparticle of ethyl violet with a molybdate/iodine tetrachloride complex as a probe for molybdoarsenate.

2006

23/6/16 (Item 1 from file: 34)

17239519 Genuine Article#: 243XZ Number of References: 12 Determination of drinking water-arsenic in nano gram level using flow injection analysis system atomic absorption spectrometry and an interpretation for the cause behind contamination ( ABSTRACT AVAILABLE ) Publication date: 20071100

23/6/17 (Item 2 from file: 34)

17200535 Genuine Article#: 238RK Number of References: 24 The electrochemical detection of ammonia in drinking water based on multi-walled carbon nanotube/copper nanoparticle composite paste electrodes ( ABSTRACT AVAILABLE ) Publication date: 20071212

23/6/18 (Item 3 from file: 34)

17193307 Genuine Article#: 239AV Number of References: 21

Development and characterization of a novel ELISA based assay for the quantitation of sub- nanomolar levels of neoepitope exposed NITEGE-containing aggrecan fragments ( ABSTRACT AVAILABLE ) Publication date: 20071201

23/6/19 (Item 4 from file: 34)

17183515 Genuine Article#: 238SH Number of References: 32 Determination of gold by nanometer titanium dioxide immobilized on silica gel packed microcolumn and flame atomic absorption spectrometry in geological and water samples ( ABSTRACT AVAILABLE ) Publication date: 20071205

23/6/20 (Item 5 from file: 34)

17174337 Genuine Article#: 236DL Number of References: 69 Synthesis and characterization of poly (divinylbenzene)-coated magnetic iron oxide nanoparticles as precursor for the formation of air-stable carbon-coated iron crystalline nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20080101

23/6/23 (Item 8 from file: 34)

17163980 Genuine Article#: 234SG Number of References: 30 Assessment of nanocomposite alumina supported on multi-wall carbon nanotubes as sorbent for on-line nickel preconcentration in water samples ( ABSTRACT AVAILABLE ) Publication date: 20071201

23/6/24 (Item 9 from file: 34)

17163964 Genuine Article#: 234SG Number of References: 12 Preparation of hydrophilic silicalite-1 nanocrystal-layered membrane for separation of water from water-acetone solution by pervaporation ( ABSTRACT AVAILABLE ) Publication date: 20071201

23/6/26 (Item 11 from file: 34)

17152930 Genuine Article#: 234WH Number of References: 38

Simulation of adsorption and separation of ethanol-water mixture with zeolite and carbon nanotube ( ABSTRACT AVAILABLE ) Publication date: 20071201

23/6/27 (Item 12 from file: 34)

17141680 Genuine Article#: 233NL Number of References: 30 Water-assisted growth and characterization of SnO2 nanobelts ( ABSTRACT AVAILABLE ) Publication date: 20071200

23/6/28 (Item 13 from file: 34)

17129230 Genuine Article#: 232WM Number of References: 44 SERS detection of environmental pollutants in humic acid-gold nanoparticle composite materials

( ABSTRACT AVAILABLE ) Publication date: 20070000

23/6/29 (Item 14 from file: 34)

17107048 Genuine Article#: 231HQ Number of References: 34 Extraction of chromium, copper, and cadmium in environmental samples using cross-linked chitosanbound FeC nano-particles as solid-phase extractant and determination by flame atomic absorption Spectrometry ( ABSTRACT AVAILABLE ) Publication date: 20070900

23/6/31 (Item 16 from file: 34)

17095340 Genuine Article#: 227HE Number of References: 29 Gold nanoclusters deposited on SiO2 via water as buffer layer: CO-IRAS and TPD characterization ( ABSTRACT AVAILABLE ) Publication date: 20071108

23/6/32 (Item 17 from file: 34)

17089657 Genuine Article#: 229FC Number of References: 30 Characterization of surface water on Au core Pt-group metal shell nanoparticles coated electrodes by surface-enhanced Raman spectroscopy ( ABSTRACT AVAILABLE ) Publication date: 20070000

23/6/33 (Item 18 from file: 34)

17087278 Genuine Article#: 227AM Number of References: 32 Speciation analysis of inorganic arsenic in water samples by immobilized nanometer titanium dioxide separation and graphite furnace atomic absorption spectrometric determination ( ABSTRACT AVAILABLE ) Publication date: 20071017

23/6/34 (Item 19 from file: 34)

17087270 Genuine Article#: 227AO Number of References: 22 Sensitive determination of fungicides and prometryn in environmental water samples using multiwalled carbon nanotubes solid-phase extraction cartridge ( ABSTRACT AVAILABLE ) Publication date: 20071029

23/6/36 (Item 21 from file: 34)

17055486 Genuine Article#: 221VP Number of References: 17 Characterization and preparation of low molecular weight water soluble chitosan nanoparticle modified with cell targeting ligand for efficient gene delivery ( ABSTRACT AVAILABLE ) Publication date: 20070900

23/6/37 (Item 22 from file: 34)

17051787 Genuine Article#: 221LF Number of References: 46 The aerosol OT plus n-butanol plus n-heptane plus water system: Phase behavior, structure characterization, and application to Pt70Fe30 nanoparticle synthesis ( ABSTRACT AVAILABLE ) Publication date: 20071023

23/6/38 (Item 23 from file: 34)

17033172 Genuine Article#: 221ZV Number of References: 31 Characterization and photoluminescence of CdS nanoparticles synthesized in diethyl ether- sodium dioctylsulfosuceinate-water microemulsion system ( ABSTRACT AVAILABLE ) Publication date: 20071000

23/6/39 (Item 24 from file: 34)

17022953 Genuine Article#: 217XZ Number of References: 15 Electrical characterization of a single electrospun porous SnO2 nanoribbon in ambient air ( ABSTRACT AVAILABLE ) Publication date: 20071031

23/6/40 (Item 25 from file: 34)

17015830 Genuine Article#: 219TH Number of References: 29 Quantification of six phytoestrogens at the nanogram per liter level in aqueous environmental samples using C-13(3)-labeled internal standards ( ABSTRACT AVAILABLE ) Publication date: 20071017

23/6/41 (Item 26 from file: 34)

16999267 Genuine Article#: 216PL Number of References: 28 Thermal characterization of a nanofluid comprising nanocrystalline ZrO2 dispersed in water and ethylene glycol ( ABSTRACT AVAILABLE ) Publication date: 20070000

23/6/42 (Item 27 from file: 34)

16979519 Genuine Article#: 214KG Number of References: 38 Water vapor detection with individual tin oxide nanowires ( ABSTRACT AVAILABLE ) Publication date: 20071024

23/6/43 (Item 28 from file: 34)

16972441 Genuine Article#: 215NA Number of References: 17 Detection of short X-ray pulses excited by an atmospheric-pressure discharge of nanosecond duration in air ( ABSTRACT AVAILABLE ) Publication date: 20070900

23/6/44 (Item 29 from file: 34)

16966549 Genuine Article#: 214YU Number of References: 31 Application of nano-FIA-Direct-EI-MS to determine diethylene glycol in produced formation water discharges and seawater samples ( ABSTRACT AVAILABLE ) Publication date: 20070900

23/6/45 (Item 30 from file: 34)

16962876 Genuine Article#: 213QI Number of References: 51 A functionalized gold nanoparticles and Rhodamine 6G based fluorescent sensor for high sensitive and selective detection of mercury(II) in environmental water samples ( ABSTRACT AVAILABLE ) Publication date: 20070905

23/6/46 (Item 31 from file: 34)

16941401 Genuine Article#: 200VC Number of References: 5 Formation of copper sulfide nanoparticles in a flooded soil: Potential for colloid-facilitated transport of contaminants

Publication date: 20070800

23/6/47 (Item 32 from file: 34)

16940872 Genuine Article#: 200VC Number of References: 0 EXAFS analysis of reactive nanoscale iron oxidation in water

Publication date: 20070800

23/6/48 (Item 33 from file: 34)

16933264 Genuine Article#: 213DL Number of References: 28 Water-gas shift reaction over aluminum promoted Cu/CeO2 nanocatalysts characterized by

XRD, BET, TPR and cyclic voltammetry (CV) ( ABSTRACT AVAILABLE ) Publication date: 20071000

23/6/49 (Item 34 from file: 34)

16928217 Genuine Article#: 211GS Number of References: 43 Effect of water filling on the electronic and vibrational resonances of carbon nanotubes: Characterizing tube opening by Raman spectroscopy ( ABSTRACT AVAILABLE ) Publication date: 20070903

23/6/50 (Item 35 from file: 34)

16925650 Genuine Article#: 197BM Number of References: 33 Synthesis of titania and titanate nanomaterials and their application in environmental analytical chemistry ( ABSTRACT AVAILABLE ) Publication date: 20070731

23/6/51 (Item 36 from file: 34)

16915798 Genuine Article#: 214LY Number of References: 131 Micro- and nanomechanical sensors for environmental, chemical, and biological detection ( ABSTRACT AVAILABLE ) Publication date: 20070000

23/6/52 (Item 37 from file: 34)

16872284 Genuine Article#: 198JI Number of References: 30 Nanometer-sized zirconium dioxide microcolumn separation /preconcentration of trace metals and their determination by ICP-OES in environmental and biological samples ( ABSTRACT AVAILABLE ) Publication date: 20070700

23/6/53 (Item 38 from file: 34)

16871729 Genuine Article#: 206CD Number of References: 26 Synthesis and characterization of shaped ZnS nanocrystals in water in oil microemulsions ( ABSTRACT AVAILABLE )

Publication date: 20070900

23/6/54 (Item 39 from file: 34)

16825586 Genuine Article#: 205SZ Number of References: 42 Multiwalled carbon nanotubes for speciation of chromium in environmental samples ( ABSTRACT AVAILABLE ) Publication date: 20070817

23/6/55 (Item 40 from file: 34)

16804290 Genuine Article#: 194FZ Number of References: 19 Structural characterization of nanocrystalline TiO2 from ionic liquid-water solvent mixture and its photocatalytic activity ( ABSTRACT AVAILABLE ) Publication date: 20070700

23/6/56 (Item 41 from file: 34)

16787681 Genuine Article#: 199YG Number of References: 44 Synthesis and characterization of water-soluble silsesquioxane-based nanoparticles by hydrolytic condensation of triethoxysilane derived from 2-hydroxyethyl acrylate ( ABSTRACT AVAILABLE ) Publication date: 20070814

23/6/57 (Item 42 from file: 34)

16777376 Genuine Article#: 192IK Number of References: 18 Small-angle x-ray scattering measurement of a mist of ethanol nanodroplets: An approach to understanding ultrasonic separation of ethanol-water mixtures ( ABSTRACT AVAILABLE ) Publication date: 20070721

23/6/58 (Item 43 from file: 34)

16745946 Genuine Article#: 190AM Number of References: 19 Characterization of carbon nanotubes exposed to Na or bombarded with Na+ at room temperature ( ABSTRACT AVAILABLE ) Publication date: 20070701

23/6/59 (Item 44 from file: 34)

16736024 Genuine Article#: 187YA Number of References: 39 A water-soluble hybrid material of single-walled carbon nanotubes with an amphiphilic poly(phenyleneethynylene): Preparation, characterization, and photovoltaic properties ( ABSTRACT AVAILABLE ) Publication date: 20070800

23/6/60 (Item 45 from file: 34)

16730912 Genuine Article#: 186EN Number of References: 83 Zero-versus one-dimensional water-soluble CdTe Nanocrystals - Synthesis and photophysical characterization ( ABSTRACT AVAILABLE ) Publication date: 20070712

23/6/61 (Item 46 from file: 34)

16724835 Genuine Article#: 187GL Number of References: 45 Treatment of pesticide contaminated surface water for production of potable water by a coagulation-adsorption- nanofiltration approach ( ABSTRACT AVAILABLE ) Publication date: 20070625

23/6/62 (Item 47 from file: 34)

16658656 Genuine Article#: 184CP Number of References: 31 Growth and characterization of nitrogen-doped single-walled carbon nanotubes by water- plasma chemical vapour deposition ( ABSTRACT AVAILABLE ) Publication date: 20070718

23/6/63 (Item 48 from file: 34)

16656831 Genuine Article#: 194RI Number of References: 265 Preparation and properties of magnetic nano- and microsized particles for biological and environmental separations ( ABSTRACT AVAILABLE ) Publication date: 20070700

23/6/64 (Item 49 from file: 34)

16639982 Genuine Article#: 181YE Number of References: 45 Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization

( ABSTRACT AVAILABLE ) Publication date: 20071000

23/6/65 (Item 50 from file: 34)

16636974 Genuine Article#: 194OQ Number of References: 3 Chemical detection in water by single-walled carbon nanotubes-based optical fiber sensors ( ABSTRACT AVAILABLE ) Publication date: 20070700

23/6/67 (Item 52 from file: 34)

16607316 Genuine Article#: 177WA Number of References: 24 Development and characterization of Al2Cu and Ag2Al nanoparticle dispersed water and ethylene glycol based nanofluid ( ABSTRACT AVAILABLE ) Publication date: 20070515

23/6/68 (Item 53 from file: 34)

16606889 Genuine Article#: 177HX Number of References: 18 Characterization of nanobubbles on hydrophobic surfaces in water ( ABSTRACT AVAILABLE ) Publication date: 20070619

23/6/69 (Item 54 from file: 34)

16595615 Genuine Article#: 176NR Number of References: 20 Gene expression in nanotoxicology research: Analysis by differential display in BALB3T3 fibroblasts exposed to cobalt particles and ions ( ABSTRACT AVAILABLE ) Publication date: 20070515

23/6/70 (Item 55 from file: 34)

16595485 Genuine Article#: 175WP Number of References: 15 SnOx obtaining by thermal oxidation of nanoscale tin films in the air and its characterization ( ABSTRACT AVAILABLE ) Publication date: 20070604

23/6/71 (Item 56 from file: 34)

16594896 Genuine Article#: 176ME Number of References: 14 Combination of separation/preconcentration based on nanoscale TiO2 and FAAS for the simultaneous determination of Cr(III)/Cr(VI) in water ( ABSTRACT AVAILABLE ) Publication date: 20070500

23/6/72 (Item 57 from file: 34)

16580166 Genuine Article#: 175BT Number of References: 36 An integrated simulation environment realizing the ability of nano-photonic crystals to detect and quantify submicron and microdamage in materials ( ABSTRACT AVAILABLE ) Publication date: 20070500

23/6/73 (Item 58 from file: 34)

16557544 Genuine Article#: 172WM Number of References: 22 High performance nanoporous carbon membranes for air separation ( ABSTRACT AVAILABLE ) Publication date: 20070500

23/6/74 (Item 59 from file: 34)

16547240 Genuine Article#: 170CS Number of References: 32 A water soluble nanostructured platinum (0) metal catalyst from platinum carbonyl molecular clusters: Synthesis, characterization and application in the selective hydrogenations of olefins, ketones and aldehydes ( ABSTRACT AVAILABLE ) Publication date: 20070601

23/6/75 (Item 60 from file: 34)

16485657 Genuine Article#: 165RI Number of References: 26 Evaluation ofreverse osmosis and nanofiltration for in situ persulfate remediated groundwater ( ABSTRACT AVAILABLE ) Publication date: 20070405

23/6/76 (Item 61 from file: 34)

16474455 Genuine Article#: 164ZN Number of References: 25 Preparation and characterization of lamellar-like Mg(OH)(2) nanostructures via natural oxidation of Mg metal in formamide/ water mixture ( ABSTRACT AVAILABLE ) Publication date: 20070605

23/6/79 (Item 64 from file: 34)

16434857 Genuine Article#: 169AR Number of References: 22 Speciation analysis of chromium in natural water samples by electrothermal atomic absorbance spectrometry after separation/preconcentration with nanometer-sized zirconium oxide immobilized on silica gel ( ABSTRACT AVAILABLE ) Publication date: 20070500

23/6/80 (Item 65 from file: 34)

16434851 Genuine Article#: 160RH Number of References: 30 Nanometer-sized alumina coated with chromotropic acid as solid phase metal extractant from environmental samples and determination by inductively coupled plasma atomic emission spectrometry ( ABSTRACT AVAILABLE ) Publication date: 20070600

23/6/81 (Item 66 from file: 34)

16434836 Genuine Article#: 160RH Number of References: 43 Nanometer SiO2 modified with 5-sulfosalicylic acid as selective solid-phase extractant for Fe(III) determination by ICP-AES from biological and natural water samples ( ABSTRACT AVAILABLE ) Publication date: 20070600

23/6/83 (Item 68 from file: 34)

16430543 Genuine Article#: 161VP Number of References: 12 Preparation and characterization of anodized Pt-TiO2 nanotube arrays for water splitting ( ABSTRACT AVAILABLE ) Publication date: 20070300

23/6/84 (Item 69 from file: 34)

16383267 Genuine Article#: 156UL Number of References: 18 Synthesis and characterization of highly dispersed antimony-doped stannic hydroxide nanoparticles: Effects of the azeotropic solvents to remove water on the properties and microstructures of the nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20070400

23/6/85 (Item 70 from file: 34)

16379997 Genuine Article#: 156GG Number of References: 34 Formation of multilayered vaterite via phase separation, crystalline transformation, and self- assembly of nanoparticles at the air /water interface ( ABSTRACT AVAILABLE ) Publication date: 20070419

23/6/86 (Item 71 from file: 34)

16372808 Genuine Article#: 157VM Number of References: 15 Developmental toxicity in zebrafish (Danio rerio) embryos after exposure to manufactured nanomaterials: Buckminsterfullerene aggregates (nC(60)) and fullerol ( ABSTRACT AVAILABLE ) Publication date: 20070500

23/6/87 (Item 72 from file: 34)

16360623 Genuine Article#: 161EK Number of References: 0 The role of environmental contaminants in ros-mediated signal transduction pathways triggered by nanoparticles in lung epithelial cells

Publication date: 20070300

23/6/88 (Item 73 from file: 34)

16357328 Genuine Article#: 155UJ Number of References: 33

Investigation of the feasibility of TiO2 nanotubes for the enrichment of DDT and its metabolites at trace levels in environmental water samples ( ABSTRACT AVAILABLE ) Publication date: 20070413

23/6/90 (Item 75 from file: 34)

16328946 Genuine Article#: 151VY Number of References: 21 Synthesis and characterization of polymeric films and nanotubule nets used to assemble selective sensors for nitrite detection in drinking water ( ABSTRACT AVAILABLE ) Publication date: 20070308

23/6/92 (Item 77 from file: 34)

16323489 Genuine Article#: 152FZ Number of References: 10 Mechanism analysis and preparation of core-shell TiO2/SiO2 nanoparticles by H-2/air flame combustions ( ABSTRACT AVAILABLE ) Publication date: 20070300

23/6/93 (Item 78 from file: 34)

16303601 Genuine Article#: 155UH Number of References: 11 Carbon nanohorn sensor to detect ozone in water ( ABSTRACT AVAILABLE ) Publication date: 20070400

23/6/95 (Item 80 from file: 34)

16271883 Genuine Article#: 153PZ Number of References: 32 Flow injection on-line solid phase extraction using multi-walled carbon nanotubes as sorbent for cold vapor atomic fluorescence spectrometric determination of trace mercury in water samples ( ABSTRACT AVAILABLE ) Publication date: 20070100

23/6/96 (Item 81 from file: 34)

16265871 Genuine Article#: 147DU Number of References: 94 Water, proton, and ion transport: from nanotubes to proteins

( ABSTRACT AVAILABLE ) Publication date: 20070100

23/6/97 (Item 82 from file: 34)

16261395 Genuine Article#: 147MC Number of References: 47 Synthesis and characterization of water-soluble and bifunctional ZnO-Au nanocomposites ( ABSTRACT AVAILABLE ) Publication date: 20070315

23/6/98 (Item 83 from file: 34)

16245675 Genuine Article#: 145LU Number of References: 30 Polarity-dependent electrochemically controlled transport of water through carbon nanotube membranes ( ABSTRACT AVAILABLE ) Publication date: 20070300

23/6/99 (Item 84 from file: 34)

16218479 Genuine Article#: 142KZ Number of References: 30 Effect of temperature on the transport of water and neutral solutes across nanofiltration membranes ( ABSTRACT AVAILABLE ) Publication date: 20070313

23/6/100 (Item 85 from file: 34)

16203305 Genuine Article#: 140WG Number of References: 35 Simultaneous on-line preconcentration and determination of trace metals in environmental samples using a modified nanometer-sized alumina packed micro-column by flow injection combined with ICP-OES ( ABSTRACT AVAILABLE ) Publication date: 20070228

23/6/101 (Item 86 from file: 34)

16176168 Genuine Article#: 140XH Number of References: 16 Determination of trace cadmium in environmental samples by nanometer-titanium dioxide separation /preconcentration-graphite furnace atomic absorption spectroscopy ( ABSTRACT AVAILABLE ) Publication date: 20060900

23/6/102 (Item 87 from file: 34)

16175877 Genuine Article#: 145HC Number of References: 29 Synthesis and characterization of wavelength-tunable, water -soluble, and near-infrared- emitting CdHgTe nanorods

Publication date: 20070320

23/6/103 (Item 88 from file: 34)

16141098 Genuine Article#: 139AO Number of References: 16 Net analyte signal-based simultaneous determination of ethanol and water by quartz crystal nanobalance sensor ( ABSTRACT AVAILABLE ) Publication date: 20070228

23/6/104 (Item 89 from file: 34)

16123180 Genuine Article#: 138TE Number of References: 48 Glutamate, water and ion transport through a charged nanosize pore ( ABSTRACT AVAILABLE ) Publication date: 20070200

23/6/106 (Item 91 from file: 34)

16091927 Genuine Article#: 136RA Number of References: 28 Preparation and characterization of nanostructured CuO thin films for photoelectrochemical splitting of water ( ABSTRACT AVAILABLE ) Publication date: 20061200

23/6/107 (Item 92 from file: 34)

16088995 Genuine Article#: 136PP Number of References: 24 Comparison of multiwalled carbon nanotubes and a conventional absorbent on the enrichment of sulfonylurea herbicides in water samples

( ABSTRACT AVAILABLE ) Publication date: 20070200

23/6/108 (Item 93 from file: 34)

16067872 Genuine Article#: 133JQ Number of References: 14 Conductive carbon-nanotube/polymer composites: Spectroscopic monitoring of the exfoliation process in water ( ABSTRACT AVAILABLE ) Publication date: 20070400

23/6/109 (Item 94 from file: 34)

16039430 Genuine Article#: 131WE Number of References: 25 Simultaneous determination of cyanazine, chlorotoluron and chlorbenzuron in environmental water samples with SPE multiwalled carbon nanotubes and LC ( ABSTRACT AVAILABLE ) Publication date: 20070100

23/6/110 (Item 95 from file: 34)

16039356 Genuine Article#: 130EA Number of References: 17 Preparation and characterization of water-soluble iron-sulfur cluster nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20070100

23/6/111 (Item 96 from file: 34)

15986579 Genuine Article#: 123VU Number of References: 18 Trace analysis of triasulfuron and bensulfuron-methyl in water samples using a carbon nanotubes packed cartridge in combination with high-performance liquid chromatography ( ABSTRACT AVAILABLE ) Publication date: 20070100

23/6/113 (Item 98 from file: 34)

15975735 Genuine Article#: 122VI Number of References: 8 Nanofiltration for oil-fields water injection operations: analysis of osmotic pressure and scale tendency ( ABSTRACT AVAILABLE )

Publication date: 20061130

23/6/114 (Item 99 from file: 34)

15975734 Genuine Article#: 122VI Number of References: 8 Nanofiltration for oil-fields water injection operations: analysis of concentration polarization ( ABSTRACT AVAILABLE ) Publication date: 20061130

23/6/115 (Item 100 from file: 34)

15969354 Genuine Article#: 125BF Number of References: 33 Application of Raman spectroscopy and sequential injection analysis for pH measurements with water dispersion of polyaniline nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20070115

23/6/116 (Item 101 from file: 34)

15931864 Genuine Article#: 118KQ Number of References: 15 Templated assembly of water-soluble nano-capsules: Inter-phase sequestration, storage, and separation of hydrocarbon gases

Publication date: 20061227

23/6/117 (Item 102 from file: 34)

15929480 Genuine Article#: 119BV Number of References: 33 Gas and water liquid transport through nanoporous block copolymer membranes ( ABSTRACT AVAILABLE ) Publication date: 20061215

23/6/118 (Item 103 from file: 34)

15925623 Genuine Article#: 117KT Number of References: 39 Multiwalled carbon nanotubes coated fibers for solid-phase microextraction of polybrominated diphenyl ethers in water and milk samples before gas chromatography with electron-capture detection ( ABSTRACT AVAILABLE ) Publication date: 20061222

23/6/119 (Item 104 from file: 34)

15913158 Genuine Article#: 118FA Number of References: 30 Continuous scanning of the mobility and size distribution of charged clusters and nanometer particles in atmospheric air and the Balanced Scanning Mobility Analyzer BSMA ( ABSTRACT AVAILABLE ) Publication date: 20061200

23/6/120 (Item 105 from file: 34)

15816882 Genuine Article#: 108YU Number of References: 3 Temperature dependence of water and neutral solutes transport in nanofiltration membranes

Publication date: 20061120

23/6/121 (Item 106 from file: 34)

15811017 Genuine Article#: 111ND Number of References: 17 Influence factors for the synthesis of water-soluble CdSe/CdS core-shell nanoparticles and their effects on the spectral characterization of CdSe/CdS ( ABSTRACT AVAILABLE ) Publication date: 20061128

23/6/122 (Item 107 from file: 34)

15760729 Genuine Article#: 105HQ Number of References: 27 Spectrophotometric determination of trace arsenic in water samples using a nanoparticle of ethyl violet with a molybdate-iodine tetrachloride complex as a probe for molybdoarsenate ( ABSTRACT AVAILABLE ) Publication date: 20061115

23/6/123 (Item 108 from file: 34)

15700579 Genuine Article#: BFD52 Number of References: 29 SAXS and XAFS analysis in forming of metal nanoparticles in water-in-scCO(2) microemulsions ( ABSTRACT AVAILABLE ) Publication date: 20060000

23/6/125 (Item 110 from file: 34)

15665080 Genuine Article#: 094TS Number of References: 27 Speciation of antimony by preconcentration of Sb(III) and Sb(V) in water samples onto nanometer-size titanium dioxide and selective determination by flow injection-hydride generation-atomic absorption spectrometry ( ABSTRACT AVAILABLE ) Publication date: 20061000

23/6/126 (Item 111 from file: 34)

15650985 Genuine Article#: 091UI Number of References: 43 Analysis of titanium nanoparticles created by laser irradiation under liquid environments ( ABSTRACT AVAILABLE ) Publication date: 20061012

23/6/127 (Item 112 from file: 34)

15638901 Genuine Article#: 092XQ Number of References: 34 Buckling and postbuckling analysis of single-walled carbon nanotubes in thermal environments via molecular dynamics simulation ( ABSTRACT AVAILABLE ) Publication date: 20061100

23/6/128 (Item 113 from file: 34)

15634344 Genuine Article#: 091GI Number of References: 35 Luminescence of functionalized carbon nanotubes as a tool to monitor bundle formation and dissociation in water: The effect of plasmid-DNA complexation ( ABSTRACT AVAILABLE ) Publication date: 20060918

23/6/129 (Item 114 from file: 34)

15632146 Genuine Article#: 089QE Number of References: 22 Nanoporous zeolite thin film-based fiber intrinsic Fabry-Perot interferometric sensor for detection of dissolved organics in water ( ABSTRACT AVAILABLE ) Publication date: 20060800

23/6/130 (Item 115 from file: 34)

15586844 Genuine Article#: 088ZR Number of References: 24 Determination of the trace refractory elements V, Nb and Ta in environmental samples by ICP-MS after separation and preconcentration with nanometre-sized alumina microcolumns following chemical modification by gallic acid ( ABSTRACT AVAILABLE ) Publication date: 20060000

23/6/131 (Item 116 from file: 34)

15576282 Genuine Article#: 084ZX Number of References: 22 Selective fluorescence determination of chromium (VI) in water samples with terbium composite nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20060900

23/6/133 (Item 118 from file: 34)

15556464 Genuine Article#: 050YE Number of References: 0 Investigation of water in nanoporous spaces: Characterization of SOMS, Na2Nb2-xTixO6- x(OH)x center dot H2O (x=0.0 and 0.4) using inelastic neutron ncattering, NMR and DFT calculations

Publication date: 20060326

23/6/137 (Item 122 from file: 34)

15555681 Genuine Article#: 050YE Number of References: 0 Analysis of bacterial spore permeability to water and ions using NanoSecondary Ion Mass Spectrometry (NanoSIMS)

Publication date: 20060326

23/6/138 (Item 123 from file: 34)

15555574 Genuine Article#: 050YE Number of References: 0 Triblock copolymer coatings enhances nanoiron transport and localizes nanoiron at the DNAPL/water interface

Publication date: 20060326

23/6/139 (Item 124 from file: 34)

15555369 Genuine Article#: 050YE Number of References: 0 Reactivity of nanoscale magnetite with groundwater contaminants

Publication date: 20060326

23/6/140 (Item 125 from file: 34)

15555151 Genuine Article#: 050YE Number of References: 0 Effect of groundwater geochemistry on nanoiron transport in saturated porous media

Publication date: 20060326

23/6/141 (Item 126 from file: 34)

15533436 Genuine Article#: 082FX Number of References: 43 Optical and bioelectrochemical characterization of water -miscible ionic liquids based composites of multiwalled carbon nanotubes ( ABSTRACT AVAILABLE ) Publication date: 20060900

23/6/142 (Item 127 from file: 34)

15491753 Genuine Article#: 076RA Number of References: 46 Using multi-walled carbon nanotubes as solid phase extraction adsorbents to determine dichlorodiphenyltrichloroethane and its metabolites at trace level in water samples by high performance liquid chromatography with UV detection ( ABSTRACT AVAILABLE ) Publication date: 20060901

23/6/143 (Item 128 from file: 34)

15436937 Genuine Article#: 072AE Number of References: 24 Sensitive determination of thiamethoxam, imidacloprid and acetamiprid in environmental water samples with solid-phase extraction packed with multiwalled carbon nanotubes prior to high-performance liquid chromatography ( ABSTRACT AVAILABLE ) Publication date: 20060800

23/6/144 (Item 129 from file: 34)

15400455 Genuine Article#: 068OM Number of References: 32 Characterization and evaluation of electrolyte influence on canola oil/water nano-emulsion ( ABSTRACT AVAILABLE ) Publication date: 20060000

23/6/145 (Item 130 from file: 34)

15366348 Genuine Article#: 063EY Number of References: 24 Characterization of Rh-Cr mixed-oxide nanoparticles dispersed on (Ga1-xZnx)(N1-xOx) as a cocatalyst for visible-light-driven overall water splitting ( ABSTRACT AVAILABLE ) Publication date: 20060720

23/6/146 (Item 131 from file: 34)

15352560 Genuine Article#: 061TO Number of References: 17 Preparation and characterization of CuI nanorods using Cu(dmg)(2) as precursor via water-in- oil (w/o) microemulsions ( ABSTRACT AVAILABLE ) Publication date: 20060000

23/6/147 (Item 132 from file: 34)

15345458 Genuine Article#: 060MJ Number of References: 36 Microwave-assisted growth and characterization of water -dispersed CdTe/CdS core-shell nanocrystals with high photoluminescence ( ABSTRACT AVAILABLE ) Publication date: 20060713

23/6/148 (Item 133 from file: 34)

15276892 Genuine Article#: 052JD Number of References: 48 Synthesis and characterization of water-soluble multiwalled carbon nanotubes grafted by a thermoresponsive polymer ( ABSTRACT AVAILABLE ) Publication date: 20060528

23/6/149 (Item 134 from file: 34)

15268710 Genuine Article#: 055GO Number of References: 24 Capture probe conjugated to paramagnetic nanoparticles for purification of Alexandrium

species (Dinophyceae) DNA from environmental samples ( ABSTRACT AVAILABLE ) Publication date: 20060700

23/6/150 (Item 135 from file: 34)

15253709 Genuine Article#: 032TJ Number of References: 0 Preparation of molecularly surface imprinted polymeric nanoparticles for the direct detection of saxitoxin in water by quartz crystal microbalance

Publication date: 20050828

23/6/151 (Item 136 from file: 34)

15251669 Genuine Article#: 032TJ Number of References: 0 Analysis of transition metal nanoparticles formed by laser ablation under solution environment

Publication date: 20050828

23/6/152 (Item 137 from file: 34)

15250590 Genuine Article#: 032TJ Number of References: 0 Synthesis, characterization, and electrochemistry of water soluble phosphine-stabilized platinum nanoparticles

Publication date: 20050828

23/6/157 (Item 142 from file: 34)

15240449 Genuine Article#: 050QK Number of References: 40 Production and characterization of stable superhydrophobic surfaces based on copper hydroxide nanoneedles mimicking the legs of water striders ( ABSTRACT AVAILABLE ) Publication date: 20060615

23/6/158 (Item 143 from file: 34)

15177333 Genuine Article#: 044OP Number of References: 19 Electrochemical-deposited In2O3 nanocrystals for H2S detecting in air ( ABSTRACT AVAILABLE )

Publication date: 20060000

23/6/161 (Item 146 from file: 34)

15136242 Genuine Article#: 040MY Number of References: 30 A pre-enrichment procedure using diethyldithiocarbamate-modified TiO2 nanoparticles for the analysis of biological and natural water samples by ICP-AES ( ABSTRACT AVAILABLE ) Publication date: 20060515

23/6/162 (Item 147 from file: 34)

15102192 Genuine Article#: 035HR Number of References: 13 84% Catalyst activity of water-assisted growth of single walled carbon nanotube forest characterization by a statistical and macroscopic approach ( ABSTRACT AVAILABLE ) Publication date: 20060420

23/6/164 (Item 149 from file: 34)

15058673 Genuine Article#: 031YI Number of References: 21 Separation of water-in-oil emulsions using glass fiber media augmented with polymer nanofibers ( ABSTRACT AVAILABLE ) Publication date: 20060000

23/6/165 (Item 150 from file: 34)

15044461 Genuine Article#: 030QB Number of References: 34 Mesoporous molecular sieve (MCM-41)-filled sodium alginate hybrid nanocomposite membranes for pervaporation separation of water-isopropanol mixtures ( ABSTRACT AVAILABLE ) Publication date: 20060401

23/6/166 (Item 151 from file: 34)

15034339 Genuine Article#: 029UX Number of References: 31 Method development for the analysis of N-nitrosodimethylamine and other N-nitrosamines in drinking water at low nanogram/liter concentrations using solid-phase extraction and gas chromatography with chemical ionization tandem mass spectrometry ( ABSTRACT AVAILABLE )

Publication date: 20060300

23/6/167 (Item 152 from file: 34)

15013624 Genuine Article#: 027YW Number of References: 0 Nanoporous ceramic adsorbent removes mercury and other environmental contaminants

Publication date: 20060300

23/6/168 (Item 153 from file: 34)

15009488 Genuine Article#: 027ZP Number of References: 23 Nanocomposite membranes of chemisorbed and physisorbed molecules on porous alumina for environmentally important separations ( ABSTRACT AVAILABLE ) Publication date: 20060420

23/6/169 (Item 154 from file: 34)

14981917 Genuine Article#: 025YA Number of References: 31 Characterization of the molecular distribution of drugs in glassy solid dispersions at the nanometer scale, using differential scanning calorimetry and gravimetric water vapour sorption techniques ( ABSTRACT AVAILABLE ) Publication date: 20060309

23/6/170 (Item 155 from file: 34)

14943294 Genuine Article#: 019TC Number of References: 17 Preparation and characterization of monoclinic sulfur nanoparticles by water-in-oil microemulsions technique ( ABSTRACT AVAILABLE ) Publication date: 20060301

23/6/171 (Item 156 from file: 34)

14937481 Genuine Article#: 020WS Number of References: 1 Characterization of ruthenium oxide nanocluster as a cocatalyst with (Gal(1-x)Zn(x))(N1-xOx) for photocatalytic overall water splitting (vol 109, pg 21915, 2005)

Publication date: 20060309

23/6/172 (Item 157 from file: 34)

14925644 Genuine Article#: 020ED Number of References: 10 Ultrastructural analysis of TiO2 nanotubes with photodecomposition of water into O-2 and H-2 implanted in the nude mouse ( ABSTRACT AVAILABLE ) Publication date: 20060300

23/6/173 (Item 158 from file: 34)

14911342 Genuine Article#: 018DS Number of References: 71 Mercaptoethane sulfonate protected, water-soluble gold and silver nanoparticles: Syntheses, characterization and their building, multilayer films with polyaniline via ion-dipole interactions

( ABSTRACT AVAILABLE ) Publication date: 20060315

23/6/174 (Item 159 from file: 34)

14911202 Genuine Article#: 016ZH Number of References: 38 Air separation by single wall carbon nanotubes: Mass transport and kinetic selectivity ( ABSTRACT AVAILABLE ) Publication date: 20060228

23/6/175 (Item 160 from file: 34)

14898371 Genuine Article#: 015VV Number of References: 120 Nanosensors in environmental analysis ( ABSTRACT AVAILABLE ) Publication date: 20060415

23/6/176 (Item 161 from file: 34)

14890404 Genuine Article#: 014ZX Number of References: 19 Synthesis and characterization of stable iron-iron oxide core-shell nanoclusters for environmental applications

( ABSTRACT AVAILABLE ) Publication date: 20060200

23/6/178 (Item 163 from file: 34)

14877473 Genuine Article#: 015TA Number of References: 27 Preparation, characterization and evaluation of water-soluble L-cysteine-capped-CdS nanoparticles as fluorescence probe for detection of Hg(II) in aqueous solution ( ABSTRACT AVAILABLE ) Publication date: 20060216

23/6/179 (Item 164 from file: 34)

14877468 Genuine Article#: 015TA Number of References: 27 Preconcentration and determination of nicosulfuron, thifensulfuron-methyl and metsulfuron- methyl in water samples using carbon nanotubes packed cartridge in combination with high performance liquid chromatography ( ABSTRACT AVAILABLE ) Publication date: 20060216

23/6/180 (Item 165 from file: 34)

14875220 Genuine Article#: 008UQ Number of References: 0 Preparation and characterization of TiO2 nanoparticles in water-in-oil emulsions.

Publication date: 20050313

23/6/181 (Item 166 from file: 34)

14875219 Genuine Article#: 008UQ Number of References: 0 Preparation and characterization of silver nanoparticles in water-in-oil emulsions.

Publication date: 20050313

23/6/182 (Item 167 from file: 34)

14849163 Genuine Article#: 011EA Number of References: 24 Growth and characterization of iron oxide nanorods/ nanobelts prepared by a simple iron- water reaction ( ABSTRACT AVAILABLE )

Publication date: 20060300

23/6/183 (Item 168 from file: 34)

14832348 Genuine Article#: 010WM Number of References: 44 Biosensor for detection of nanobacteria in water ( ABSTRACT AVAILABLE ) Publication date: 20060200

23/6/184 (Item 169 from file: 34)

14824262 Genuine Article#: 009PK Number of References: 35 Determination of atrazine and simazine in environmental water samples using multiwalled carbon nanotubes as the adsorbents for preconcentration prior to high performance liquid chromatography with diode array detector ( ABSTRACT AVAILABLE ) Publication date: 20060215

23/6/185 (Item 170 from file: 34)

14782854 Genuine Article#: 007KO Number of References: 30 Synthesis and characterization of air-stable iron nanocrystalline particles based on a single- step swelling process of uniform polystyrene template microspheres ( ABSTRACT AVAILABLE ) Publication date: 20060124

23/6/186 (Item 171 from file: 34)

14779659 Genuine Article#: 007JC Number of References: 28 Fiber optic based gas sensor with nanoporous structure for the selective detection of NO2 in air samples ( ABSTRACT AVAILABLE ) Publication date: 20060131

23/6/189 (Item 174 from file: 34)

14731768 Genuine Article#: 002AV Number of References: 0 Dye nanoparticles aid water analysis

Publication date: 20060109

23/6/190 (Item 175 from file: 34)

14691276 Genuine Article#: 995ZV Number of References: 27 Comparison of the enrichment efficiency of multiwalled carbon nanotubes, C18 silica, and activated carbon as the adsorbents for the solid phase extraction of atrazine and simazine in water samples ( ABSTRACT AVAILABLE ) Publication date: 20060100

23/6/191 (Item 176 from file: 34)

14687078 Genuine Article#: 996AD Number of References: 43 Fluid structure and transport properties of water inside carbon nanotubes ( ABSTRACT AVAILABLE ) Publication date: 20051215

23/6/192 (Item 177 from file: 34)

14676750 Genuine Article#: 996PW Number of References: 30 New surface-enhanced Raman spectroscopy substrates via self-assembly of silver nanoparticles for perchlorate detection in water ( ABSTRACT AVAILABLE ) Publication date: 20051200

23/6/193 (Item 178 from file: 34)

14675103 Genuine Article#: BDK21 Number of References: 9 Doped tin oxide nanometric films for environment monitoring ( ABSTRACT AVAILABLE ) Publication date: 20050000

23/6/195 (Item 180 from file: 34)

14661155 Genuine Article#: 992RT Number of References: 23 Preparation and characterization of Ni2+-montmorillonite/polyvinyl alcohol water-soluble nanocomposite film ( ABSTRACT AVAILABLE ) Publication date: 20050000

23/6/196 (Item 181 from file: 34)

14622852 Genuine Article#: 989MX Number of References: 30 Application of multiwalled carbon nanotubes as solid phase extraction sorbent for preconcentration of trace copper in water samples ( ABSTRACT AVAILABLE ) Publication date: 20051100

23/6/197 (Item 182 from file: 34)

14620938 Genuine Article#: 988YE Number of References: 30 Physicochemical characterization of canola oil/water nano-emulsions obtained by determination of required HLB number and emulsion phase inversion methods ( ABSTRACT AVAILABLE ) Publication date: 20060000

23/6/198 (Item 183 from file: 34)

14620923 Genuine Article#: 988YE Number of References: 24 Separation of liquid drops from air by glass fiber filters augmented with polystyrene nanofibers ( ABSTRACT AVAILABLE ) Publication date: 20060000

23/6/199 (Item 184 from file: 34)

14595580 Genuine Article#: 986GC Number of References: 58 Characterization of ruthenium oxide nanocluster as a cocatalyst with (Ga1-xZnx)(N1-xOx) for photocatalytic overall water splitting ( ABSTRACT AVAILABLE ) Publication date: 20051124

23/6/200 (Item 185 from file: 34)

14593811 Genuine Article#: 987MC Number of References: 19 Water-soluble single-walled carbon nanotubes films: Preparation, characterization and applications as electrochemical sensing films ( ABSTRACT AVAILABLE ) Publication date: 20060101

23/6/201 (Item 186 from file: 34)

14561810 Genuine Article#: 984HL Number of References: 13 Synthesis and characterization of nanocrystalline MnFe2O4: advances in thermochemical water splitting ( ABSTRACT AVAILABLE ) Publication date: 20051000

23/6/203 (Item 188 from file: 34)

14512432 Genuine Article#: 981HJ Number of References: 28 Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with a matrix of carbon nanotubes for the analysis of low-mass compounds in environmental samples ( ABSTRACT AVAILABLE ) Publication date: 20051101

23/6/204 (Item 189 from file: 34)

14502766 Genuine Article#: 978PZ Number of References: 62 Synthesis and characterization of water-soluble carbon nanotubes from mustard soot ( ABSTRACT AVAILABLE ) Publication date: 20051000

23/6/205 (Item 190 from file: 34)

14395068 Genuine Article#: 969MS Number of References: 24 Preparation and characterization of uniform nanosized cephradine by combination of reactive precipitation and liquid anti-solvent precipitation under high gravity environment ( ABSTRACT AVAILABLE ) Publication date: 20050914

23/6/206 (Item 191 from file: 34)

14383455 Genuine Article#: 965SM Number of References: 13 Air pollution monitoring and GIS modeling: a new use of nanotechnology based solid state gas sensors ( ABSTRACT AVAILABLE ) Publication date: 20050400

23/6/209 (Item 194 from file: 34)

14361966 Genuine Article#: 966CG Number of References: 41 Synthesis and characterization of water soluble saccharide functionalized polysiloxanes and their use as polymer surfactants for the stabilization of polycaprolactone nanoparticles

( ABSTRACT AVAILABLE ) Publication date: 20050905

23/6/210 (Item 195 from file: 34)

14340058 Genuine Article#: 960BG Number of References: 30 Transport behavior of water confined in carbon nanotubes ( ABSTRACT AVAILABLE ) Publication date: 20050800

23/6/211 (Item 196 from file: 34)

14333467 Genuine Article#: 961VV Number of References: 36 Magnetic nanoparticle-antibody conjugates for the separation of Escherichia coli 0157 : H7 in ground beef

( ABSTRACT AVAILABLE ) Publication date: 20050900

23/6/213 (Item 198 from file: 34)

14263781 Genuine Article#: 953TG Number of References: 56 Pervaporation separation of water plus isopropanol mixtures using novel nanocomposite membranes of poly(vinyl alcohol) and polyaniline ( ABSTRACT AVAILABLE ) Publication date: 20050901

23/6/214 (Item 199 from file: 34)

14258345 Genuine Article#: 953WR Number of References: 12 A nanofiltration retention model for trace contaminants in drinking water sources ( ABSTRACT AVAILABLE ) Publication date: 20050710

23/6/215 (Item 200 from file: 34)

14256646 Genuine Article#: 955RW Number of References: 25 Highly luminescent water-soluble CdTe nanowires as fluorescent probe to detect copper(II) ( ABSTRACT AVAILABLE )

Publication date: 20050000

23/6/217 (Item 202 from file: 34)

14225460 Genuine Article#: 950VW Number of References: 14 Kinetics of water-assisted single-walled carbon nanotube synthesis revealed by a time-evolution analysis ( ABSTRACT AVAILABLE ) Publication date: 20050729

23/6/218 (Item 203 from file: 34)

14217817 Genuine Article#: 952GK Number of References: 36 Air separation by single wall carbon nanotubes: Thermodynamics and adsorptive selectivity ( ABSTRACT AVAILABLE ) Publication date: 20050722

23/6/219 (Item 204 from file: 34)

14209020 Genuine Article#: 952DT Number of References: 37 Separation and purification of functionalised water-soluble rnulti-walled carbon nanotubes by flow field-flow fractionation ( ABSTRACT AVAILABLE ) Publication date: 20050800

23/6/220 (Item 205 from file: 34)

14194565 Genuine Article#: 948LK Number of References: 38 Determining the mass concentration of fluoride in water by nonradiative energy transport between lanthanide ions inside nanostructures in the presence of an electrolyte ( ABSTRACT AVAILABLE ) Publication date: 20050600

23/6/221 (Item 206 from file: 34)

14137945 Genuine Article#: 945IJ Number of References: 43 Speciation of dissolved iron(II) and iron(III) in environmental water samples by gallic acid- modified nanometer-sized alumina micro-column separation and ICP-MS determination ( ABSTRACT AVAILABLE ) Publication date: 20050000

23/6/223 (Item 208 from file: 34)

14123721 Genuine Article#: 942ZH Number of References: 9 Multi-walled carbon nanotubes as a solid-phase extraction adsorbent for the determination of chlorophenols in environmental water samples ( ABSTRACT AVAILABLE ) Publication date: 20050722

23/6/224 (Item 209 from file: 34)

14091933 Genuine Article#: 913TZ Number of References: 0 Detection of heavy metal ions in drinking water using conducting polymer nanojunctions.

Publication date: 20050313

23/6/229 (Item 214 from file: 34)

14091762 Genuine Article#: 913TZ Number of References: 0 Multi-walled carbon nanotube exposure in human epidermal keratinocytes: Localization and proteomic analysis.

Publication date: 20050313

23/6/230 (Item 215 from file: 34)

14090683 Genuine Article#: 913TZ Number of References: 0 Water porosimetry: A new technique to characterize hydrophobic porous surfaces and wetting in nano-confinement

Publication date: 20050313

23/6/231 (Item 216 from file: 34)

14089370 Genuine Article#: 913TZ Number of References: 0 Water-soluble semiconductor nanocrystals: Synthesis and characterization of ZsSe and Mn(II) doped ZnSe nanocrystals

Publication date: 20050313

23/6/232 (Item 217 from file: 34)

14087738 Genuine Article#: 913TZ Number of References: 0 Monitoring reactive oxygen species dynamics from human epithelial-like cells exposed to single-walled carbon nanotubes.

Publication date: 20050313

23/6/233 (Item 218 from file: 34)

14061305 Genuine Article#: 937AJ Number of References: 8 Development of bio-degradable adsorbent having nano-size molecular-recognition sites and actual clean-up and analysis of an aqueous environment ( ABSTRACT AVAILABLE ) Publication date: 20050600

23/6/235 (Item 220 from file: 34)

14027710 Genuine Article#: 934SY Number of References: 17 Novel integrated electrochemical nano-biochip for toxicity detection in water ( ABSTRACT AVAILABLE ) Publication date: 20050600

23/6/236 (Item 221 from file: 34)

14025996 Genuine Article#: 933HM Number of References: 65 Synthesis and characterization of water soluble single-walled carbon nanotube graft copolymers ( ABSTRACT AVAILABLE ) Publication date: 20050608

23/6/237 (Item 222 from file: 34)

14024512 Genuine Article#: 933VQ Number of References: 23 Magnetically modulated optical nanoprobes (MagMOONs) for detection and measurement of biologically important ions against the natural background fluorescence of intracellular environments ( ABSTRACT AVAILABLE ) Publication date: 20050501

23/6/238 (Item 223 from file: 34)

14023319 Genuine Article#: 934HT Number of References: 39 Transport of a liquid water and methanol mixture through carbon nanotubes under a chemical potential gradient ( ABSTRACT AVAILABLE ) Publication date: 20050601

23/6/240 (Item 225 from file: 34)

14011778 Genuine Article#: 933FN Number of References: 18 Detection of 2,4,6-trichloroanisole in chlorinated water at nanogram per litre levels by SPME- GC-ECD ( ABSTRACT AVAILABLE ) Publication date: 20050500

23/6/241 (Item 226 from file: 34)

13977157 Genuine Article#: 928SS Number of References: 16 Characterization of anatase nanocrystal-precipitated coatings from (100-x)SiO2 center dot xTiO(2) gel films via the sol-gel process with boiling hot water treatment ( ABSTRACT AVAILABLE ) Publication date: 20050100

23/6/242 (Item 227 from file: 34)

13939356 Genuine Article#: 926PP Number of References: 27 Preparation and characterization of Ag@TiO2 core-shell nanoparticles in water-in-oil emulsions ( ABSTRACT AVAILABLE ) Publication date: 20050506

23/6/243 (Item 228 from file: 34)

13921917 Genuine Article#: 924MM Number of References: 74 Water-soluble full-length single-wall carbon nanotube polyelectrolytes: Preparation and characterization ( ABSTRACT AVAILABLE ) Publication date: 20050512

23/6/244 (Item 229 from file: 34)

13900524 Genuine Article#: 921UR Number of References: 21

Thermoluminescence characterization of nanocrystalline and single Y3Al5O12 crystal exposed to beta-irradiation for dosimetric applications ( ABSTRACT AVAILABLE ) Publication date: 20050400

23/6/245 (Item 230 from file: 34)

13897046 Genuine Article#: 923AT Number of References: 35 Supercritical water oxidation of wastewater from LCD manufacturing process: kinetic and formation of chromium oxide nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20050500

23/6/246 (Item 231 from file: 34)

13872619 Genuine Article#: 921AZ Number of References: 18 Synthesis and characterization of La-2(CO3)(3) nanostructures in the triton X- 100/cyclohexane/water reverse inicelles ( ABSTRACT AVAILABLE ) Publication date: 20050415

23/6/248 (Item 233 from file: 34)

13845663 Genuine Article#: 918KV Number of References: 17 Synthesis and characterization of water-soluble multi-walled carbon nanotubes functionalized with polycystine ( ABSTRACT AVAILABLE ) Publication date: 20050405

23/6/249 (Item 234 from file: 34)

13768387 Genuine Article#: 908TN Number of References: 38 Classical theoretical characterization of the surface plasmon absorption band for silver spherical nanoparticles suspended in water and ethylene glycol

( ABSTRACT AVAILABLE ) Publication date: 20050300

23/6/250 (Item 235 from file: 34)

13683322 Genuine Article#: 902QS Number of References: 36 Distribution patterns and controllable transport of water inside and outside charged single- walled carbon nanotubes ( ABSTRACT AVAILABLE ) Publication date: 20050222

23/6/251 (Item 236 from file: 34)

13653141 Genuine Article#: 899SB Number of References: 28 Preparation and characterization of water-soluble US nanocrystals by surface modification of ethylene diamine ( ABSTRACT AVAILABLE ) Publication date: 20050400

23/6/252 (Item 237 from file: 34)

13650950 Genuine Article#: 900XH Number of References: 23 Stability of nanocrystals: Thermodynamic analysis of oxidation and re-reduction of cobalt in water/hydrogen mixtures ( ABSTRACT AVAILABLE ) Publication date: 20050303

23/6/253 (Item 238 from file: 34)

13635469 Genuine Article#: 899CX Number of References: 36 Formation and characterization of titania nanosheet -precipitated coatings via sol-gel process with hot water treatment under vibration ( ABSTRACT AVAILABLE ) Publication date: 20050222

23/6/255 (Item 240 from file: 34)

13599145 Genuine Article#: 851UZ Number of References: 0 Use of silver-polydimethylsiloxane nanocomposites as SERS substrates for the analysis of model environmental pollutants in water.

Publication date: 20040822

23/6/256 (Item 241 from file: 34)

13590020 Genuine Article#: 894BC Number of References: 26

A molecular dynamics analysis of the mechanical effect of water on the deformation of silicon monocrystals subjected to nano-indentation ( ABSTRACT AVAILABLE ) Publication date: 20050100

23/6/257 (Item 242 from file: 34)

13584757 Genuine Article#: 895CJ Number of References: 21 Phase development and structural characterization of calcium phosphate ceramics-polyacrylic acid nanocomposites at room temperature in water-methanol mixtures ( ABSTRACT AVAILABLE ) Publication date: 20041200

23/6/258 (Item 243 from file: 34)

13561750 Genuine Article#: 893SI Number of References: 29 Band gap shift, structural characterization and phase transformation of CdSe thin films from nanocrystalline cubic to nanorod hexagonal on air annealing ( ABSTRACT AVAILABLE ) Publication date: 20050100

23/6/259 (Item 244 from file: 34)

13554406 Genuine Article#: 891YJ Number of References: 14 Characterization of stone powder/TiO2 core/shell composite particles prepared from TiO2 nanoparticles via heterocoagulation in a water system ( ABSTRACT AVAILABLE ) Publication date: 20050100

23/6/260 (Item 245 from file: 34)

13539006 Genuine Article#: 888ZL Number of References: 7 Laser-optical characterization of air-borne nanoparticles by time-resolved laser-induced incandescence (TIRE-LII) ( ABSTRACT AVAILABLE ) Publication date: 20050100

23/6/262 (Item 247 from file: 34)

13516002 Genuine Article#: 851AJ Number of References: 0 Dynamic nanoscale biosensor array for environmental monitoring.

Publication date: 20040328

23/6/263 (Item 248 from file: 34)

13515943 Genuine Article#: 851AJ Number of References: 0 Synthesis, characterization and environmental application of nanocrystalline silicalite-1.

Publication date: 20040328

23/6/264 (Item 249 from file: 34)

13485718 Genuine Article#: 887EU Number of References: 0 Nanosensors to monitor space radiation exposure

Publication date: 20050100

23/6/265 (Item 250 from file: 34)

13468163 Genuine Article#: 885LL Number of References: 38 Biofouling of ultra- and nanofiltration membranes for drinking water treatment characterized by fluorescence in situ hybridization (FISH) ( ABSTRACT AVAILABLE ) Publication date: 20050201

23/6/266 (Item 251 from file: 34)

13436959 Genuine Article#: 881IK Number of References: 9 Separated syntheses of Gd-hybridized single-wall carbon nanohorns, single-wall nanotubes and multi-wall nanostructures by arc discharge in water with support of gas injection

Publication date: 20050000

23/6/267 (Item 252 from file: 34)

13428509 Genuine Article#: 879NM Number of References: 36 Faceting characterization of tin dioxide nanocrystals deposited by spray pyrolysis from stannic chloride water solution ( ABSTRACT AVAILABLE ) Publication date: 20050103

23/6/268 (Item 253 from file: 34)

13419548 Genuine Article#: 878RX Number of References: 30 The characterization of nanosized nickel-zinc ferrites synthesized within reverse micelles of CTAB/1-hexanol/water microemulsion ( ABSTRACT AVAILABLE ) Publication date: 20041200

23/6/269 (Item 254 from file: 34)

13411908 Genuine Article#: 877ZU Number of References: 14 Titanium dioxide nanoparticle separation/preconcentration and graphite furnace atomic absorption spectrometric determination of trace Pb in water samples ( ABSTRACT AVAILABLE ) Publication date: 20041100

23/6/270 (Item 255 from file: 34)

13405403 Genuine Article#: 874XN Number of References: 29 Ethanol and H2S gas detection in air and in reducing and oxidising ambience: application of pattern recognition to analyse the output from temperature-modulated nanoparticulate WO3 gas sensors ( ABSTRACT AVAILABLE ) Publication date: 20050103

23/6/271 (Item 256 from file: 34)

13394744 Genuine Article#: 874WI Number of References: 18 Preparation and characterization of SiO2/Tio(2) core/shell composite particles using TiO2 nanoparticles via heterocoagulation in a water system ( ABSTRACT AVAILABLE ) Publication date: 20041100

23/6/272 (Item 257 from file: 34)

13386501 Genuine Article#: 874ZS Number of References: 18 A novel nuclear spin-lattice relaxation filter for separating the free and absorbed water in a matrix of titanate nanotubes ( ABSTRACT AVAILABLE ) Publication date: 20041201

23/6/273 (Item 258 from file: 34)

13377195 Genuine Article#: 873VZ Number of References: 55 Gold nanoparticles synthesized in a water-in-oil microemulsion: electrochemical characterization and effect of the surface structure on the oxygen reduction reaction ( ABSTRACT AVAILABLE ) Publication date: 20041215

13335717 Genuine Article#: 871IH Number of References: 27 A direct analysis of nanomolar metal ions in environmental water samples with Nafion-coated microelectrodes ( ABSTRACT AVAILABLE ) Publication date: 20041115

23/6/276 (Item 261 from file: 34)

13316299 Genuine Article#: 868XF Number of References: 56 Electrochemical characterization of platinum-ruthenium nanoparticles prepared by water-in- oil microemulsion ( ABSTRACT AVAILABLE ) Publication date: 20041101

23/6/277 (Item 262 from file: 34)

13305650 Genuine Article#: 867JD Number of References: 19 Thermoluminescence characterization of Tb3+ and Ce3+ doped nanocrystalline Y3Al5O12 exposed to X- and beta-ray irradiation ( ABSTRACT AVAILABLE ) Publication date: 20041100

23/6/279 (Item 264 from file: 34)

13219157 Genuine Article#: 858AN Number of References: 34 Natural and modified nanomaterials as sorbents of environmental contaminants ( ABSTRACT AVAILABLE ) Publication date: 20040900

23/6/282 (Item 267 from file: 34)

13218294 Genuine Article#: 858KK Number of References: 52

Ultramorphological analysis of resin-dentin interfaces produced with water-based single-step and two-step adhesives: Nanoleakage expression ( ABSTRACT AVAILABLE ) Publication date: 20041015

23/6/283 (Item 268 from file: 34)

13212843 Genuine Article#: 858CR Number of References: 22 Fabrication of zinc oxide nanostructures on gold-coated silicon substrate by thermal chemical reactions vapor transport deposition in air ( ABSTRACT AVAILABLE ) Publication date: 20040000

23/6/284 (Item 269 from file: 34)

13182421 Genuine Article#: 856DC Number of References: 20 Carboxylation multi-walled carbon nanotubes modified with LiClO4 for water vapour detection ( ABSTRACT AVAILABLE ) Publication date: 20040900

23/6/285 (Item 270 from file: 34)

13181898 Genuine Article#: 855BF Number of References: 21 Nanoparticles-based chemical gas sensors for outdoor air quality monitoring microstations ( ABSTRACT AVAILABLE ) Publication date: 20040925

23/6/286 (Item 271 from file: 34)

13178376 Genuine Article#: 857VB Number of References: 31 Experimental measurement and model analysis of damping effect in nanoscale mechanical beam resonators in air ( ABSTRACT AVAILABLE ) Publication date: 20041001

23/6/287 (Item 272 from file: 34)

13173766 Genuine Article#: 854XZ Number of References: 20 Detecting N-nitrosamines in drinking water at nanogram per liter levels using ammonia positive chemical ionization ( ABSTRACT AVAILABLE ) Publication date: 20040915

23/6/288 (Item 273 from file: 34)

13148136 Genuine Article#: 853ZB Number of References: 27 Metal ion analysis in contaminated water samples using anodic stripping voltammetry and a nanocrystalline diamond thin-film electrode ( ABSTRACT AVAILABLE ) Publication date: 20040920

23/6/289 (Item 274 from file: 34)

13114183 Genuine Article#: 850LF Number of References: 47 About the methods of preparation of poly(ethylene oxide)-b-poly(epsilon-caprolactone) nanoparticles in water analysis by dynamic light scattering ( ABSTRACT AVAILABLE ) Publication date: 20040802

23/6/290 (Item 275 from file: 34)

13061858 Genuine Article#: 844TJ Number of References: 33 Preparation and characterization of water-soluble jingle-bell-shaped silica-coated cadmium sulfide nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20040812

23/6/291 (Item 276 from file: 34)

13038030 Genuine Article#: 843GN Number of References: 31 Transport properties and distribution of water molecules confined in hydrophobic nanopores and nanoslits ( ABSTRACT AVAILABLE ) Publication date: 20040803

23/6/292 (Item 277 from file: 34)

13035627 Genuine Article#: 843TR Number of References: 33 gamma-MPTMS modified nanometer-sized alumina micro-column separation and preconcentration of trace amounts of Hg, Cu, Au and Pd in biological, environmental and geological samples and their determination by inductively coupled plasma mass spectrometry ( ABSTRACT AVAILABLE ) Publication date: 20040000

23/6/293 (Item 278 from file: 34)

13030107 Genuine Article#: 843PK Number of References: 7 Preparation and characterization of nanometer indium oxide by precipitation method without ammonia water ( ABSTRACT AVAILABLE ) Publication date: 20040800

23/6/294 (Item 279 from file: 34)

13004268 Genuine Article#: 840KJ Number of References: 31 In situ polymerization and characterization of polyamide-6/silica nanocomposites derived from water glass ( ABSTRACT AVAILABLE ) Publication date: 20040800

23/6/295 (Item 280 from file: 34)

12976244 Genuine Article#: 838HA Number of References: 12 Polyamide/SDS-clay hybrid nanocomposite membrane application to water-ethanol mixture pervaporation separation ( ABSTRACT AVAILABLE ) Publication date: 20040815

23/6/296 (Item 281 from file: 34)

12947102 Genuine Article#: 830FJ Number of References: 20 Removal of sulfates and other inorganics from potable water by nanofiltration membranes of characterized porosity ( ABSTRACT AVAILABLE ) Publication date: 20040700

23/6/297 (Item 282 from file: 34)

12914284 Genuine Article#: 833DI Number of References: 41 A room-temperature TiO2-nanotube hydrogen sensor able to self-clean photoactively from environmental contamination ( ABSTRACT AVAILABLE ) Publication date: 20040200

23/6/299 (Item 284 from file: 34)

12870537 Genuine Article#: 829UG Number of References: 50 Preparation and characterization of water-soluble pH-sensitive nanocarriers for drug delivery ( ABSTRACT AVAILABLE ) Publication date: 20040611

23/6/301 (Item 286 from file: 34)

12854318 Genuine Article#: 826RK Number of References: 30 Formation and characterization of water-soluble platinum nanoparticles using a unique approach based on the hydrosilylation reaction

Publication date: 20040608

23/6/302 (Item 287 from file: 34)

12837419 Genuine Article#: 825MC Number of References: 21 Transport properties of water vapor in polylactide/montmorillonite nanocomposites ( ABSTRACT AVAILABLE ) Publication date: 20040000

23/6/303 (Item 288 from file: 34)

12829616 Genuine Article#: 825JZ Number of References: 14 Synthesis and characterization of water-soluble CdSe/ZnS core-shell nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20040600

23/6/304 (Item 289 from file: 34)

12774926 Genuine Article#: 819MQ Number of References: 27 Highly fluorescent streptavidin-coated CdSe nanoparticles: Preparation in water,

characterization, and micropatterning ( ABSTRACT AVAILABLE ) Publication date: 20040511

23/6/307 (Item 292 from file: 34)

12761289 Genuine Article#: 761PU Number of References: 0 Nanoscale photosynthesis: Renewable hydrogen production and biosensors for environmental monitoring.

Publication date: 20030300

23/6/308 (Item 293 from file: 34)

12761247 Genuine Article#: 761PU Number of References: 0 Nanocomposite and tunable membranes for environmental separations

Publication date: 20030300

23/6/310 (Item 295 from file: 34)

12761108 Genuine Article#: 761PU Number of References: 0 Bioengineering approach to the production of nanoparticles for environmental remediation

Publication date: 20030300 23/6/312 (Item 297 from file: 34)

12736078 Genuine Article#: 816IF Number of References: 33 Effects of adsorption of alcohol and water on the electrical transport of carbon nanotube bundles ( ABSTRACT AVAILABLE ) Publication date: 20040331

23/6/313 (Item 298 from file: 34)

12693577 Genuine Article#: 811PF Number of References: 13 Development and validation of a highly sensitive gas chromatographic-mass spectrometric screening method for the simultaneous determination of nanogram levels of fentanyl, sufentanil and alfentanil in air and surface contamination wipes ( ABSTRACT AVAILABLE ) Publication date: 20040507

23/6/314 (Item 299 from file: 34)

12677845 Genuine Article#: 810WA Number of References: 33 Advances in air quality monitoring via nanotechnology ( ABSTRACT AVAILABLE ) Publication date: 20040200

23/6/315 (Item 300 from file: 34)

12611670 Genuine Article#: 805DI Number of References: 16 Nanostructural ZnO fabricated by vapor-phase transport in air ( ABSTRACT AVAILABLE ) Publication date: 20040120

23/6/316 (Item 301 from file: 34)

12611580 Genuine Article#: 804OL Number of References: 32 Nanometer-size titanium dioxide separation/preconcentration and FAAS determination of trace Zn and Cd in water sample ( ABSTRACT AVAILABLE ) Publication date: 20040315

23/6/317 (Item 302 from file: 34)

12601749 Genuine Article#: 803MX Number of References: 22 Preparation, photo- and thermo-luminescence characterization of Tb3+ and Ce3+ doped nanocrystalline Y3Al5O12 exposed to UV-irradiation ( ABSTRACT AVAILABLE ) Publication date: 20040400

23/6/318 (Item 303 from file: 34)

12596561 Genuine Article#: 803IO Number of References: 28 Electric field-controlled water permeation coupled to ion transport through a nanopore ( ABSTRACT AVAILABLE ) Publication date: 20040315

23/6/319 (Item 304 from file: 34)

12564159 Genuine Article#: 778QB Number of References: 25

Growth and characterization of zinc oxide nano/micro-fibers by thermal chemical reactions and vapor transport deposition in air ( ABSTRACT AVAILABLE ) Publication date: 20040200

23/6/321 (Item 306 from file: 34)

12545551 Genuine Article#: 751JF Number of References: 0 Ion exchanger supported inorganic nanoparticles for environmental separation.

Publication date: 20030900

23/6/322 (Item 307 from file: 34)

12545141 Genuine Article#: 751JF Number of References: 0 Effect of monomeric sequence on nanophase-segregated structure and water transport in Nafion 117.

Publication date: 20030900

23/6/323 (Item 308 from file: 34)

12464285 Genuine Article#: 769GY Number of References: 19 Preparation and characterization of zinc sulfide nanoparticles under high-gravity environment ( ABSTRACT AVAILABLE ) Publication date: 20040202

23/6/324 (Item 309 from file: 34)

12419811 Genuine Article#: 764GZ Number of References: 26 Evaluation of multi-walled carbon nanotubes as an adsorbent for trapping volatile organic compounds from environmental samples ( ABSTRACT AVAILABLE ) Publication date: 20040213

23/6/326 (Item 311 from file: 34)

12302575 Genuine Article#: 750TA Number of References: 48 New water-soluble calix[4]arene-bis(benzocrown-6) for caesium-sodium separation by

nanofiltration-complexation ( ABSTRACT AVAILABLE ) Publication date: 20031215

23/6/328 (Item 313 from file: 34)

12121154 Genuine Article#: 733MJ Number of References: 20 Water-soluble fluorescent nanospheres as fluorosensor for detection of Cu2+ ( ABSTRACT AVAILABLE ) Publication date: 20031005

23/6/329 (Item 314 from file: 34)

12116058 Genuine Article#: 733PA Number of References: 22 Characterization of DNA adducts from lung tissue of asphalt fume- exposed mice by nanoflow liquid chromatography quadrupole time-of-flight mass spectrometry ( ABSTRACT AVAILABLE ) Publication date: 20031101

23/6/330 (Item 315 from file: 34)

12093448 Genuine Article#: 731GT Number of References: 33 Synthesis, structure and spectroscopic characterization of water-soluble CdS nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20031006

23/6/331 (Item 316 from file: 34)

12090901 Genuine Article#: 729MJ Number of References: 34 Multi-walled carbon nanotubes packed cartridge for the solid-phase extraction of several phthalate esters from water samples and their determination by high performance liquid chromatography ( ABSTRACT AVAILABLE ) Publication date: 20031008

23/6/332 (Item 317 from file: 34)

12085483 Genuine Article#: 725ZX Number of References: 4 Proton transport through water-filled carbon nanotubes (vol 90, art no 105902, 2003)

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23/6/333 (Item 318 from file: 34)

12063599 Genuine Article#: 727QN Number of References: 31 Nano-high-performance liquid chromatography-electron ionization mass spectrometry approach for environmental analysis ( ABSTRACT AVAILABLE ) Publication date: 20031001

23/6/334 (Item 319 from file: 34)

12046289 Genuine Article#: 724PT Number of References: 28 Synthesis, characterization and properties of water-soluble gold nanoparticles with tunable core size ( ABSTRACT AVAILABLE ) Publication date: 20030000

23/6/335 (Item 320 from file: 34)

12020919 Genuine Article#: 721WQ Number of References: 25 Single-wall carbon nanotube interaction with gases: Sample contaminants and environmental monitoring ( ABSTRACT AVAILABLE ) Publication date: 20030917

23/6/336 (Item 321 from file: 34)

12006462 Genuine Article#: BX43J Number of References: 1 Nano-topography characterization of axisymmetric aspherical ground surfaces ( ABSTRACT AVAILABLE ) Publication date: 20030000

23/6/337 (Item 322 from file: 34)

12003092 Genuine Article#: 717YX Number of References: 49 Osmotic water transport through carbon nanotube membranes ( ABSTRACT AVAILABLE ) Publication date: 20030902

23/6/338 (Item 323 from file: 34)

12003002 Genuine Article#: 717ZP Number of References: 26 Polypropylene-graft-maleic anhydride-nanocomposites: I - Characterization and thermal stability of nanocomposites produced under nitrogen and in air ( ABSTRACT AVAILABLE ) Publication date: 20031000

23/6/339 (Item 324 from file: 34)

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23/6/341 (Item 326 from file: 34)

11958747 Genuine Article#: 713UH Number of References: 21 Nanosized spinel NiFe2O4: A novel material for the detection of liquefied petroleum gas in air ( ABSTRACT AVAILABLE ) Publication date: 20030928

23/6/342 (Item 327 from file: 34)

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23/6/343 (Item 328 from file: 34)

11925057 Genuine Article#: 710LA Number of References: 23 Aligned ZnO nanofibre array prepared by vapour transport in air ( ABSTRACT AVAILABLE ) Publication date: 20030800

23/6/344 (Item 329 from file: 34)

11784327 Genuine Article#: 698GJ Number of References: 18 Voltammetric determination of 1-naphthylacetic acid in soil samples using carbon nanotubes film modified electrode ( ABSTRACT AVAILABLE ) Publication date: 20030000

23/6/346 (Item 331 from file: 34)

11723225 Genuine Article#: 687BE Number of References: 34 Preparation and characterization of polypyrrole-silica colloidal nanocomposites in water- methanol mixtures ( ABSTRACT AVAILABLE ) Publication date: 20030615

23/6/347 (Item 332 from file: 34)

11712551 Genuine Article#: 687ZN Number of References: 14 Monitoring nano-flow rate of water by atomic emission detection using helium radio-frequency plasma ( ABSTRACT AVAILABLE ) Publication date: 20030000

23/6/348 (Item 333 from file: 34)

11706863 Genuine Article#: 685CX Number of References: 7 Nanosensors enable portable detectors for environmental and medical applications ( ABSTRACT AVAILABLE ) Publication date: 20030500

23/6/349 (Item 334 from file: 34)

11704850 Genuine Article#: 684YU Number of References: 36 Studies on the growth and characterization of CdS and PbS nanoparticles using sugar-ester nonionic water-in-oil microemulsion ( ABSTRACT AVAILABLE ) Publication date: 20030600

23/6/350 (Item 335 from file: 34)

11676987 Genuine Article#: 681TG Number of References: 21 Synthesis and characterization of PbS nanocrystals in water/C12E9/cyclohexane

microemulsions ( ABSTRACT AVAILABLE ) Publication date: 20030400

23/6/351 (Item 336 from file: 34)

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23/6/352 (Item 337 from file: 34)

11616349 Genuine Article#: 676XD Number of References: 28 Surface functionalization of oil-in-water nanoemulsion with a reactive copolymer: colloidal characterization and peptide immobilization ( ABSTRACT AVAILABLE ) Publication date: 20030515

23/6/353 (Item 338 from file: 34)

11605934 Genuine Article#: 673WV Number of References: 64 Fabrication and characterization of silicon nanocrystals by thermal oxidation of a-Si : H films in air ( ABSTRACT AVAILABLE ) Publication date: 20030300

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23/6/359 (Item 344 from file: 34)

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23/6/362 (Item 347 from file: 34)

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23/6/363 (Item 348 from file: 34)

11352793 Genuine Article#: 640LY Number of References: 36 Predicting contaminant removal during municipal drinking water nanofiltration using artificial neural networks

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23/6/364 (Item 349 from file: 34)

11327179 Genuine Article#: 638ZM Number of References: 60 Water-in-oil microemulsion synthesis of platinum-ruthenium nanoparticles, their characterization and electrocatalytic properties ( ABSTRACT AVAILABLE ) Publication date: 20030128

23/6/365 (Item 350 from file: 34)

11310405 Genuine Article#: 635CL Number of References: 16 Preparation and characterization of nanofiltration membranes fabricated from poly(amidesulfonamide), and their application in water-oil separation ( ABSTRACT AVAILABLE ) Publication date: 20030314

23/6/366 (Item 351 from file: 34)

11227943 Genuine Article#: 625HM Number of References: 10 Mass spectrometric analysis of water-soluble gold nanoclusters ( ABSTRACT AVAILABLE ) Publication date: 20021000

23/6/367 (Item 352 from file: 34)

11170093 Genuine Article#: 615KY Number of References: 13 Synthesis and characterization of water soluble gold nanoclusters of varied core size ( ABSTRACT AVAILABLE ) Publication date: 20021200

23/6/368 (Item 353 from file: 34)

11081035 Genuine Article#: 603YW Number of References: 17 Synthesis and characterization of dodecanethiol-capped cadmium sulfide nanoparticles in a Winsor II microemulsion of diethyl ether/AOT/water

Publication date: 20021015

23/6/369 (Item 354 from file: 34)

11081031 Genuine Article#: 603YW Number of References: 49 Synthesis and magnetic characterization of zinc ferrite nanoparticles with different environments: Powder, colloidal solution, and zinc ferrite-silica core-shell nanoparticles ( ABSTRACT AVAILABLE ) Publication date: 20021015

23/6/370 (Item 355 from file: 34)

11064938 Genuine Article#: 601FB Number of References: 4 Regeneration of process water containing surfactants by nanofiltration - investigation and modelling of mass transport ( ABSTRACT AVAILABLE ) Publication date: 20020000

23/6/371 (Item 356 from file: 34)

11029756 Genuine Article#: 599QY Number of References: 4 Nanofiltration and adsorption on powdered adsorbent as process combination for the treatment of severely contaminated waste water ( ABSTRACT AVAILABLE ) Publication date: 20020910

23/6/372 (Item 357 from file: 34)

10938367 Genuine Article#: 583RM Number of References: 0 Preparation and characterization of nanofiltration membranes fabricated from poly(amidesulfonamide)s and application in water-oil separation.

Publication date: 20020818

23/6/373 (Item 358 from file: 34)

10923534 Genuine Article#: 584WW Number of References: 16 Nanostructured zeolite 4A molecular sieving air separation membranes ( ABSTRACT AVAILABLE ) Publication date: 20020821

23/6/374 (Item 359 from file: 34)

10860386 Genuine Article#: 576MT Number of References: 10 Single-file transport of water molecules through a carbon nanotube - art. no. 064503 ( ABSTRACT AVAILABLE ) Publication date: 20020805

23/6/375 (Item 360 from file: 34)

10840423 Genuine Article#: 575JD Number of References: 20 High sensitivity NO2 sensors for environmental monitoring produced using laser ablated nanocrystalline metal oxides ( ABSTRACT AVAILABLE ) Publication date: 20020725

23/6/376 (Item 361 from file: 34)

10831325 Genuine Article#: 573YJ Number of References: 16 D/H ratios of atmospheric H-2 in urban air: Results using new methods for analysis of nanomolar H-2 samples ( ABSTRACT AVAILABLE ) Publication date: 20020700

23/6/377 (Item 362 from file: 34)

10801945 Genuine Article#: 564CD Number of References: 0 Semiconductor nanostructures for the simultaneous detection and degradation of organic contaminants in water.

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23/6/378 (Item 363 from file: 34)

10705617 Genuine Article#: 559VH Number of References: 23 Differential pulse cathodic stripping voltammetric determination of nanomolar levels of dissolved sulfide applicable to field analysis of groundwater ( ABSTRACT AVAILABLE ) Publication date: 20020522

23/6/379 (Item 364 from file: 34)

10581112 Genuine Article#: 544DM Number of References: 44

Formation and characterization of Au-Ag bimetallic nanoparticles in water-in-oil microemulsions ( ABSTRACT AVAILABLE ) Publication date: 20020000

23/6/380 (Item 365 from file: 34)

10493510 Genuine Article#: 532TZ Number of References: 81 Anisole hydrogenation with well-characterized polyoxoanion- and tetrabutylammonium- stabilized Rh(0) nanoclusters: Effects of added water and acid, plus enhanced catalytic rate, lifetime, and partial hydrogenation selectivity ( ABSTRACT AVAILABLE ) Publication date: 20020325

23/6/382 (Item 367 from file: 34)

10368324 Genuine Article#: 517YY Number of References: 11 Transport properties in the nanofiltration of NaNO3- water solutions with a weak acid polyelectrolyte membrane ( ABSTRACT AVAILABLE ) Publication date: 20020331

23/6/383 (Item 368 from file: 34)

10313954 Genuine Article#: 512UD Number of References: 21 Synthesis and characterization of water-soluble chiral conducting polymer nanocomposites ( ABSTRACT AVAILABLE ) Publication date: 20020108

23/6/384 (Item 369 from file: 34)

10282135 Genuine Article#: 506MR Number of References: 20 Design, nano-fabrication and analysis of near-infrared 2D photonic crystal air-bridge structures ( ABSTRACT AVAILABLE ) Publication date: 20020100

23/6/385 (Item 370 from file: 34)

10141143 Genuine Article#: 489YL Number of References: 11 Silicalite/poly(dimethylsiloxane) nanocomposite pervaporation membranes for acetic

acid/water separation ( ABSTRACT AVAILABLE ) Publication date: 20011100

23/6/386 (Item 371 from file: 34)

10140610 Genuine Article#: 490JM Number of References: 29 CdS nanocrystals from a quaternary water-in-oil microemulsion: Preparation and characterization of self-assembled layers ( ABSTRACT AVAILABLE ) Publication date: 20011101

23/6/387 (Item 372 from file: 34)

09879305 Genuine Article#: 459WL Number of References: 23 On-line high-precision stable hydrogen isotopic analyses on nanoliter water samples ( ABSTRACT AVAILABLE ) Publication date: 20010801

23/6/389 (Item 374 from file: 34)

09877062 Genuine Article#: 434PH Number of References: 0 Nanomaterials for the detection of chemical agents in water.

Publication date: 20010401

23/6/390 (Item 375 from file: 34)

09873681 Genuine Article#: 434PH Number of References: 0 High throughput analyses in nanoliter beakers using air segmentation in capillary tubes.

Publication date: 20010401

23/6/391 (Item 376 from file: 34)

09853686 Genuine Article#: 455AM Number of References: 12 Oil/water separation using nanofiltration membrane technology ( ABSTRACT AVAILABLE ) Publication date: 20010000

23/6/392 (Item 377 from file: 34)

09721252 Genuine Article#: 440QA Number of References: 26 Topical transport of hydrophilic compounds using water-in-oil nanoemulsions ( ABSTRACT AVAILABLE ) Publication date: 20010604

23/6/393 (Item 378 from file: 34)

09714053 Genuine Article#: 441TH Number of References: 51 Predictive membrane transport model for nanofiltration precesses in water treatment ( ABSTRACT AVAILABLE ) Publication date: 20010600

23/6/394 (Item 379 from file: 34)

09699172 Genuine Article#: 436UJ Number of References: 33 Simplified analysis of contaminant rejection during ground- and surface water nanofiltration under the information collection rule ( ABSTRACT AVAILABLE ) Publication date: 20010700

23/6/395 (Item 380 from file: 34)

09644599 Genuine Article#: 432ZJ Number of References: 17 NEXAFS characterization of nanostructured carbon thin-films exposed to hydrogen ( ABSTRACT AVAILABLE ) Publication date: 20010300

23/6/396 (Item 381 from file: 34)

09638976 Genuine Article#: 428UZ Number of References: 9 Heat transport in nano-environments adjacent to metal-liquid interfaces: Ultrafast photothermal study ( ABSTRACT AVAILABLE ) Publication date: 20010000

23/6/399 (Item 3 from file: 35)

02207977 ORDER NO: AADAA-I3251719 Sub-continuum ion transport in air and phonon transport in nanostructures

Year: 2006 23/6/401 (Item 5 from file: 35)

02193692 ORDER NO: AADAA-I3244335 Transport mechanisms in nanoscale amorphous solid water films

Year: 2006

23/6/404 (Item 8 from file: 35)

02155089 ORDER NO: AADAA-I1436003 Synthesis and characterization of water soluble single walled carbon nanotubes graft substituted ionic polyacetylenes

Year: 2006

23/6/408 (Item 12 from file: 35)

02148145 ORDER NO: AADAA-I1433875 Optimization of a field-deployable nano-band electrode system for arsenic analysis of water

Year: 2005

23/6/409 (Item 13 from file: 35)

02129379 ORDER NO: AADAA-I3206782 The synthesis and characterization of water soluble hydroindole-based nanostructures of designed three-dimensional architectures

Year: 2005

23/6/411 (Item 15 from file: 35)

02128647 ORDER NO: AADAA-I3203426 Optical techniques for nanoscale probing and chemical detection in aqueous environments

Year: 2005

23/6/412 (Item 16 from file: 35)

02116264 ORDER NO: AADAA-I3190188 Reaction of organosilicon hydrides with inorganic surfaces: An example of surface catalyzed self-assembly, and, Water porosimetry: A new technique to characterize hydrophobic porous surfaces and wetting in nano-confinement

Year: 2005

23/6/413 (Item 17 from file: 35)

02108909 ORDER NO: AADAA-I3186312 Temperature effects on transport of water, charged, and uncharged solutes across polymeric thin film composite nanofiltration membranes: An investigation into pore- transport mechanisms and electrokinetic properties

Year: 2005

23/6/415 (Item 19 from file: 35)

02083360 ORDER NO: AADAA-I1425933 Electrical transport and switching properties of polythiophene based water soluble conducting polymer at nano scale

Year: 2005

23/6/417 (Item 21 from file: 35)

02041755 ORDER NO: AADAA-I3147315 Polymer-supported hydrated iron oxide (HFO) nanoparticles: Characterization and environmental applications

Year: 2004

23/6/418 (Item 22 from file: 35)

01973934 ORDER NO: AADAA-I3104894 Sonochemical preparation and characterization of nanoporous transition metal oxides for environmental catalysis

Year: 2003

23/6/419 (Item 23 from file: 35)

01962379 ORDER NO: AADAA-I3098469 Synthesis, characterization, and testing of carbon nanofibers for coalescence filtration of oil from compressed air and adsorption of chloroform from air

Year: 2003

23/6/420 (Item 24 from file: 35)

01901207 ORDER NO: AADAA-I3058668 Nanoscale characterization of surface-modified and surface-grafted polymers using environmental control scanning force microscopy

Year: 2002

23/6/423 (Item 1 from file: 36)

0004795283 Electrical characterization of a single electrospun porous SnO2 nanoribbon in ambient air - art. no. 435704

2007 CURC 0957-4484

23/6/424 (Item 2 from file: 36)

0004765665 Growth and characterization of nitrogen-doped single-walled carbon nanotubes by water- plasma chemical vapour deposition - art. no. 285601

2007 CURC 0957-4484

23/6/425 (Item 3 from file: 36)

0004757758 SnO/sub x/ obtaining by thermal oxidation of nanoscale tin films in the air and its

characterization

2007 INSP 0040-6090

23/6/426 (Item 4 from file: 36)

0004694913 Production and characterization of stable superhydrophobic surfaces based on copper hydroxide nanoneedles mimicking the legs of water striders

2006 INSP 1089-5647

23/6/427 (Item 5 from file: 36)

0004572608 Transport behavior of water confined in carbon nanotubes - art. no. 085420

2005 CURC 1098-0121

23/6/428 (Item 6 from file: 36)

0004564166 IP Accession No.: 05-0332002 Synthesis and characterization of water soluble single-walled carbon nanotube graft copolymers

2005 PASC 0002-7863

23/6/429 (Item 7 from file: 36)

0004432670 IP Accession No.: 05-0045156 In situ polymerization and characterization of polyamide-6/silica nanocomposites derived from water glass

2004 PASC 0959-8103

23/6/430 (Item 8 from file: 36)

0004330773 IP Accession No.: 03-0334740 Polymer-clay nanocomposites from directly micellized polymer/toluene in water and their characterization by WAXD and solid-state NMR spectroscopy

2003 PASC 0897-4756

23/6/431 (Item 1 from file: 40)

00717305 Enviroline Number: 07-11345 Development Toxicity in Zebrafish (Danio rerio) Embryos After Exposure to Manufactured Nanomaterials: Buckminsterfullerene Aggregates (nC60) and Fullerol

May 07

23/6/432 (Item 2 from file: 40)

00713840 Enviroline Number: 07-08352 Evaluation of Reverse Osmosis and Nanofiltration for in situ Persulfate Remediated Groundwater

Apr 5, 07

23/6/434 (Item 4 from file: 40)

00698982 Enviroline Number: 06-10188 Characterization of Nano- and Microparticles in Swiss Waters and their Role in Potable Water Production

2006

23/6/437 (Item 1 from file: 41)

0000318675 IP Accession No: 7448434 Study on Nanofiltration for Removal of Organics and Bacteric Contamination from Drinking Water

Publication Date: 2006

23/6/438 (Item 2 from file: 41)

0000288249 IP Accession No: 6906427 Simultaneous on-line preconcentration and determination of trace metals in environmental samples by flow injection combined with inductively coupled plasma mass spectrometry using a nanometer-sized alumina packed micro-column

Publication Date: 2005

23/6/440 (Item 4 from file: 41)

0000263193 IP Accession No: 6700279 Reduction of wastewaters and valorisation of by-products from "Serpa" cheese manufacture using nanofiltration

Book Title: 4th World Water Congress: Innovation in Wastewater Treatment Processes

Publication Date: 2005

23/6/442 (Item 6 from file: 41)

0000247999 IP Accession No: 6178066 Characterization of microparticles in raw, treated, and distributed waters by means of elemental and particle size analyses

Book Title: Nano and Micro Particles in Water and Wastewater Treatment

Publication Date: 2004

23/6/443 (Item 7 from file: 41)

0000247998 IP Accession No: 6178061 Detection of aquatic colloids in drinking water during its distribution via a water pipeline network

Book Title: Nano and Micro Particles in Water and Wastewater Treatment

Publication Date: 2004

23/6/445 (Item 1 from file: 57)

0000650977 IP Accession No: 200711-70-113876 Neutron Structure Analysis on Water Nano-tube Cluster Stabilized by Molecule-based Porous

Crystal

Publication Date: 2007

23/6/446 (Item 2 from file: 57)

0000605441 IP Accession No: 200707-90-064839 Preconcentration and separation of trace copper in water samples with nanometer-size TiO2 colloid and determination by FAAS

Publication Date: 2007

23/6/447 (Item 3 from file: 57)

0000420042 IP Accession No: 200609-22-109278 High sensitivity ozone sensors for environmental monitoring produced using laser ablated nanocrystalline metal oxides

Publication Date: 2002

23/6/448 (Item 4 from file: 57)

0000338039 IP Accession No: 200605-22-12682 Simulations of nanoscale flow: water, proton, and biopolymer transport through carbon nanotube membranes

Publication Date: 2005

23/6/449 (Item 5 from file: 57)

0000330998 IP Accession No: 200605-22-12688 Electrochemical sensors based on functionalized nanoporous silica for environmental monitoring

Publication Date: 2004

23/6/450 (Item 6 from file: 57)

0000295976 IP Accession No: 200503-21-03616

Ethanol and H2OS gas detection in air and in reducing and oxidising ambience: application of pattern recognition to analyse the output from temperature-modulated nanoparticulate WO3 gas sensors

Publication Date: 2005

23/6/452 (Item 1 from file: 65)

0006397375 Inside Conference Item ID: CN066089883 Synthesis of water-soluble silsesquioxane-based nanoparticles and characterization of hybrid interface

Conference: Society of Polymer Science - ANNUAL MEETING; 56th ( 200705 )

23/6/454 (Item 3 from file: 65)

0006372859 Inside Conference Item ID: CN065844721 An integrated NMR/nanosensor system for sensitive detection of environmental toxins and harmful microbes

Conference: NSTI Nanotech the Nanotechnology conference and trade show - Conference; Nanotechnology

23/6/457 (Item 6 from file: 65)

0006346580 Inside Conference Item ID: CN065581939 Aerospace Environmental Monitoring Using Oxide Based Micro and Nano Sensor Technology

Conference: Electrochemical Society; ECS - Meeting abstracts; 211th ( 2007; , May )

23/6/459 (Item 8 from file: 65)

0006329833 Inside Conference Item ID: CN060883955 Army requirements for micro and nanotechnology-based sensors in weapons health and battlefield environmental monitoring applications (Keynote Paper) [6172-01]

Conference: Smart structures and materials: smart electronics, MEMS, bioMEMS, and nanotechnology - Conference ( 200602 )

23/6/462 (Item 11 from file: 65)

0006196627 Inside Conference Item ID: CN059563577 Synthesis and characterization of iron nanostructures inside porous zeolites and their applications in water treatment technologies

Conference: NATO Advanced Study Institute on carbon nanotubes, from basic research to nanotechnology; Carbon nanotubes ( NATO science series ) ( 200505 )

23/6/463 (Item 12 from file: 65)

0006170128 Inside Conference Item ID: CN063751635 CANEUS2006-11066 Nano Sensors for Gas Detection in Space and Ground Support Applications

Conference: CANEUS 2006 MNT for aerospace applications - CONFERENCE ( 200609 )

23/6/464 (Item 13 from file: 65)

0006157752 Inside Conference Item ID: CN059222714 NANOCAPILLARY ARRAY INTERCONNECTS IN MULTILAYER MICROCHIPS FOR TRANSPORT CONTROL BETWEEN DIFFERENT FLUIDIC ENVIRONMENTS

Conference: International conference on miniaturized chemical and biochemical analysis systems; Micro total analysis systems 2003: proceedings of muTAS 2003 - 7th ( 200310 )

23/6/466 (Item 15 from file: 65)

0006142407 Inside Conference Item ID: CN063495863 Analysis of the Surface Adsorbed Organics of Nanosized TiO SUB 2 Photocatalyst with High Visible-Light Photocatalysis Activity by Ultrasonic Treatment under Water and Ethanol Solution

Conference: China International Conference on High-Performance Ceramics; CICC- 4 - 4th ( 200510 )

23/6/467 (Item 16 from file: 65)

0006137068 Inside Conference Item ID: CN063442471 NanoShuttles: Harnessing Motor Proteins to Transport Cargo in Synthetic Environments

Conference: Controlled nanoscale motion in biological and artificial systems - Symposium ( 200506 )

23/6/468 (Item 17 from file: 65)

0006129893 Inside Conference Item ID: CN058936787 A CONFIGURATION FOR HIGH FLOW RATE, HIGH EFFICIENCY AND LOW PRESSURE LOSS MICROMACHINED ACTIVE AIR FILTRATION ELEMENT FOR AIRBORNE MICRO- NANOSCALE PARTICLES SEPARATION AND REMOVAL

Conference: Micro electro mechanical systems:; MEMS 2005 Miami: IEEE: technical digest - International conference; 18TH ( 200501 )

23/6/469 (Item 18 from file: 65)

0006116413 Inside Conference Item ID: CN063221439 Designing Pd-on-Metal and Pd-on-Oxides Nanoparticle Catalysts for Chlorinated Solvents in Contaminated Water

Conference: The Electrochemical Society - Joint international meeting ( 200610 )

23/6/470 (Item 19 from file: 65)

0006097849 Inside Conference Item ID: CN063057811 A2-10 Microcolumn Preconcentration of Trace Metal Ions in Environmental Samples Using Nanometer Sized Alumina Immobilized with Chromotropic Acid and Determination by Inductively Coupled Plasma Atomic Emission Spectrometry

Conference: Asian symposium on ecotechnology; (ASET 13) - 13th ( 200612 )

23/6/471 (Item 20 from file: 65)

0006094791 Inside Conference Item ID: CN063027235 6145 Preparation and Characterization of Water-Based Nanofluids for Nuclear Applications

Conference: International congress on advances in nuclear power plants ( 200606 )

23/6/473 (Item 22 from file: 65)

0006027028 Inside Conference Item ID: CN062349601 Transport of Molecules Through Carbon Nanotube Channels in Aqueous Environment: A Molecular Dynamics Study

Conference: Dynamics in small confining systems - Symposium ( 200511 )

23/6/474 (Item 23 from file: 65)

05980654 Inside Conference Item ID: CN061885868 Temperature dependence of water and neutral solutes transport in nanofiltration membranes

Conference: EUROMEMBRANE 2006 - Conference ( 200609 )

23/6/475 (Item 24 from file: 65)

05978940 Inside Conference Item ID: CN061868729 25 Years of Aerosol Research in Duisburg -From Fire Detection to Air Pollution to Nanoparticles

Conference: Symposium on the history of aerosol science; History & reviews of aerosol science - 2nd ( 200110 )

23/6/477 (Item 26 from file: 65)

05900274 Inside Conference Item ID: CN061082061 SAXS and XAFS Analysis in Forming of Metal Nanoparticles in Water -in-scCO SUB 2 Microemulsions

Conference: High pressure technology of nanomaterials: 6th High Pressure School - 6th ( 200509 )

23/6/478 (Item 27 from file: 65)

05863145 Inside Conference Item ID: CN060710774 Dynamic Analysis of the Long Plain Journal Bearing in the Nanotechnology Environment

Conference: Stability control of rotating machinery; ISCORMA - 2nd:; International Symposium; 2ND ( 200308 )

23/6/479 (Item 28 from file: 65)

05863138 Inside Conference Item ID: CN060710707 Steady-State Analysis of the Long Plain Journal Bearing in the Nanotechnology Environment

Conference: Stability control of rotating machinery; ISCORMA - 2nd:; International Symposium; 2ND ( 200308 )

23/6/481 (Item 30 from file: 65)

05670919 Inside Conference Item ID: CN058788510 3E4.70 Ultrasensitive Nanogap Biosensor to Detect Changes in Structure of Water and Ice

Conference: Solid-state sensors, actuators and microsystems; Transducers '05 - 13th:; International Conference ( 200506 )

23/6/482 (Item 31 from file: 65)

05660455 Inside Conference Item ID: CN058683873 Verification of a Nanofiltration Retention Model for Organic Contaminants in Drinking Water Sources

Conference: Water quality technology conference and exposition; water knows no boundaries ( 200511 )

23/6/483 (Item 32 from file: 65)

05644922 Inside Conference Item ID: CN058528548 Air Separation by Single Wall Carbon Nanotubes: Thermodynamics and Kinetics

Conference: American Institute of Chemical Engineers; 05 AIChE - Annual meeting and full showcase ( 200510 )

23/6/484 (Item 33 from file: 65)

05596254 Inside Conference Item ID: CN058036338 Functionalized Water-Soluble Multi-Walled Carbon Nanotubes: Synthesis, Purification and Length Separation by Flow Field-Flow Fractionation

Conference: Electronic properties of novel nanostructures - 19th:; International Winter School/Euroconference ( AIP conference proceedings ) ( 200503 )

23/6/485 (Item 34 from file: 65)

05529130 Inside Conference Item ID: CN057356685 Synthesis and Characterization of Nanostructured Undoped/Doped CuO Films and their Application in Photoelectrochemical Water Splitting

Conference: Nanotechnology conference; NSTI nanotech 2005 ( 200505 )

23/6/486 (Item 35 from file: 65)

05489685 Inside Conference Item ID: CN056962231 Treatment of Nitrates in the Subsurface Environment by Nanosized Zero-valent Iron Wall Enhanced by Electrokinetic Remediation

Conference: Soil and groundwater remediation technology 1 - Annual conference; 1st ( 200311 )

23/6/487 (Item 36 from file: 65)

05384655 Inside Conference Item ID: CN055911937 Thermoluminescence characterization of nanocrystalline and single Y3Al5O12 crystal exposed to -irradiation for dosimetric applications

Conference: Proceedings of the first topical meeting on nanostructured materials and nanotechnology: CIO 2004 - Topical meeting; 1st ( 200409 )

23/6/488 (Item 37 from file: 65)

05268981 Inside Conference Item ID: CN054761765 Simulations of nanoscale flow: water, proton, and biopolymer transport through carbon nanotube membranes (Invited Paper) (5592-40)

Conference: Nanofabrication: technologies, devices and applications / - Conference ( 200410 )

23/6/489 (Item 38 from file: 65)

05231296 Inside Conference Item ID: CN054384918 Electrochemical sensors based on functionalized nanoporous silica for environmental monitoring (5593-91)

Conference: Nanosensing: materials and devices / - Conference ( 200410 )

23/6/490 (Item 39 from file: 65)

05192048 Inside Conference Item ID: CN054021906 Characterization and Manipulation of Exposed Ge Nanocrystals

Conference: Nanoparticles and nanowire building blocks: synthesis, processing, characterization and

theory / - Symposium ( 200404 )

23/6/491 (Item 40 from file: 65)

05071449 Inside Conference Item ID: CN052815913 Nanoporous TiO SUB 2 Film as Coating for Piezoelectric Crystal Sensor in the Detection of Organic Vapors in Air

Conference: International meeting on chemical sensors; IMCS - 10th ( 200407 )

23/6/493 (Item 42 from file: 65)

05020959 Inside Conference Item ID: CN052324900 Me-porphyrins application, for nano-gravimetric sensors development, for air quality detection in an environment with crude oil distillation derivates

Conference: Third International conference on porphyrins and phthalocyanines - 3rd ( 200407 )

23/6/494 (Item 43 from file: 65)

04824981 Inside Conference Item ID: CN050336773 Random Walk Model for Single-File Transport of Water Molecules through Carbon Nanotubes

Conference: International conference on unsolved problems of noise and fluctuations in physics, biology, and high technology; UPoN 2002 - International conference; 3rd ( 200209 )

23/6/497 (Item 46 from file: 65)

04071883 Inside Conference Item ID: CN042786445 AIAA-2001-5025 Nanoparticles Synthesized in Block Copolymer Micelles, Star Architectures, and Polyelectrolyte Complexes: Characterization and Potential under Microgravity Environments

Conference: Space station utilization - Conference ( 200110 )

23/6/498 (Item 47 from file: 65)

03977008 Inside Conference Item ID: CN041752452 Synthesis and Characterization of Environmentally Responsive Core -Shell Hydrogel Nanoparticles

Conference: Biomaterials for drug delivery; Biomaterials for drug delivery and tissue engineering - Symposium NN ( 200011 )

23/6/500 (Item 1 from file: 73)

0082160043 EMBASE No: 2007611166 Isothiouronium-based amphiphilic gold nanoparticles with a colorimetric response to hydrophobic anions in water: a new strategy for fluoride ion detection in the presence of a phenylboronic acid

Publication Date: January 14, 2008

23/6/501 (Item 2 from file: 73)

0082146560 EMBASE No: 2007579058 Inflammatory response of mice to manufactured titanium dioxide nanoparticles: Comparison of size effects through different exposure routes

Publication Date: September 1, 2007

23/6/502 (Item 3 from file: 73)

0082142701 EMBASE No: 2007591997 Characterization and air pressure sensing of doubly clamped multi-walled carbon nanotubes

Publication Date: January 9, 2008

23/6/503 (Item 4 from file: 73)

0082114724 EMBASE No: 2007552194 Electrical characterization of a single electrospun porous SnO SUB 2 nanoribbon in ambient air

Publication Date: October 31, 2007

23/6/504 (Item 5 from file: 73)

0081983547 EMBASE No: 2007419062 A functionalized gold nanoparticles and Rhodamine 6G based fluorescent sensor for high sensitive and selective detection of mercury(II) in environmental water samples

Publication Date: September 5, 2007

23/6/505 (Item 6 from file: 73)

0081830765 EMBASE No: 2007264872 Assessing chemical cleaning of nanofiltration membranes in a drinking water production plant: A combination of chemical composition analysis and fluorescence microscopy

Issue Title: Biofilm Systems VI Publication Date: July 3, 2007

23/6/507 (Item 8 from file: 73)

0081706413 EMBASE No: 2007140040 Investigation of the feasibility of TiO SUB 2 nanotubes for the enrichment of DDT and its metabolites at trace levels in environmental water samples

Publication Date: April 13, 2007

23/6/509 (Item 10 from file: 73)

0081050263 EMBASE No: 2006110278 Ultrastructural analysis of TiO SUB 2 nanotubes with photodecomposition of water into O SUB 2 and H SUB 2 implanted in the nude mouse

Publication Date: March 1, 2006

23/6/510 (Item 11 from file: 73)

0080972870 EMBASE No: 2006032822 Fiber optic based gas sensor with nanoporous structure for the selective detection of NO SUB 2 in air samples

Publication Date: January 31, 2006

23/6/511 (Item 12 from file: 73)

0080674799 EMBASE No: 2005319117 Pervaporation separation of water + isopropanol mixtures using novel nanocomposite

membranes of poly(vinyl alcohol) and polyaniline

Publication Date: September 1, 2005

23/6/514 (Item 15 from file: 73)

0080087916 EMBASE No: 2004272395 Polyamide/SDS-clay hybrid nanocomposite membrane application to water-ethanol mixture pervaporation separation

Publication Date: August 15, 2004

23/6/515 (Item 16 from file: 73)

0079797804 EMBASE No: 2003508520 Preparation and characterization of biodegradable nanoparticles containing a lipophilic drug in water-soluble or insoluble form

Publication Date: December 1, 2003

23/6/516 (Item 17 from file: 73)

0078813168 EMBASE No: 2001419562 Transport properties in the nanofiltration of NaNO SUB 3-water solutions with a weak acid polyelectrolyte membrane

Publication Date: March 31, 2002

23/6/517 (Item 1 from file: 76)

0001911377 IP Accession No: 6965130 Magnetic Nanoparticle-Antibody Conjugates for the Separation of escherichia Coli O157:H7 in Ground Beef

Publication Date: 2005

23/6/519 (Item 3 from file: 76)

0001757160 IP Accession No: 6178081 The effects of polymer characteristics on nano particle separation in humic substances removal by cationic polymer coagulation

Book Title: Nano and Micro Particles in Water and Wastewater Treatment

Publication Date: 2004

23/6/523 (Item 7 from file: 76)

0001683670 IP Accession No: 5829588 Novel methods for characterizing algogenic organic matter and associated nanofiltration membrane fouling

Book Title: Membranes in Drinking and Industrial Water Production III

Publication Date: 2003

23/6/524 (Item 8 from file: 76)

0001610970 IP Accession No: 5635670 Nanofiltration: Improvements of water quality in a large distribution system

Book Title: 3rd World Water Congress: Water Services Management, Operations and Monitoring

Publication Date: 2003

23/6/525 (Item 9 from file: 76)

0001592489 IP Accession No: 5402138 Determination of mass transport characteristics for natural organic matter (NOM) in ultrafiltration (UF) and nanofiltration (NF) membranes

Book Title: Second World Water Congress: Drinking Water Treatment

Publication Date: 2002

23/6/526 (Item 1 from file: 95)

02112219 20060608963 Electrochemical-deposited In(ind 2)O(ind 3) nanocrystals for H(ind 2)S detecting in air , 2006

23/6/527 (Item 2 from file: 95)

02074204 20060402906 Nanoporous ceramic adsorbent removes mercury and other environmental contaminants , 2006

23/6/528 (Item 3 from file: 95)

02030027 20051205122 Ultrasensitive nanogap biosensor to detect changes in structure of water and ice , 2005

23/6/529 (Item 4 from file: 95)

01975675 20050605706 Characterization of anatase nanocrystal-precipitated coatings from (100-x)SiO2.xTiO2 gel films via the sol gel process with boiling hot water treatment

( Charakterisierung von nanokristallausgeschiedenen Anatasbeschichtungen aus duennen (100- x)SiO2.(x)TiO2 Gelschichten ueber einen Sol-Gel-Prozess mit einer Behandlung mit kochendem Wasser ) , 2005

23/6/530 (Item 5 from file: 95)

01963016 20050208773 Biofouling of ultra- and nanofiltration membranes fordrinking water treatment characterized by fluorescence in situ hybridization (FISH) , 2005

23/6/531 (Item 6 from file: 95)

01962229 20050503661 Thermoluminescence characterization of nanocrystalline and single A3Al5O12 crystal exposed to beta-irradiation for dosimetric applications , 2005

23/6/533 (Item 8 from file: 95)

01717941 20030201525 Entwicklung und Einsatz keramischer Nanofiltrationsmembranen fuer den

produktionsintegrierten Umweltschutz am Beispiel farbstoffbelasteter Abwaesser der Textilindustrie

( Development and use of ceramic nanofiltration membranes in the production-integrated environment protection applied to the dye contaminated textile industry waste water ) , 2001

23/6/534 (Item 9 from file: 95)

01677262 20021001009 High sensitivity NO(ind 2) sensors for environmental monitoring produced using laser ablated nanocrystalline metal oxides , 2002

23/6/535 (Item 1 from file: 99)

3205378 H.W. Wilson Record Number: BAST07130176 Synthesis and Characterization of Highly Dispersed Antimony-Doped Stannic Hydroxide Nanoparticles: Effects of the Azeotropic Solvents to Remove Water on the Properties and Microstructures of the Nanoparticles

20070400

23/6/536 (Item 2 from file: 99)

2912032 H.W. Wilson Record Number: BAST05164160 Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry with a Matrix of Carbon Nanotubes for the Analysis of Low-Mass Compounds in Environmental Samples

20051101

23/6/537 (Item 3 from file: 99)

2616569 H.W. Wilson Record Number: BAST03140924 Water Self-Diffusion within Nematic Dispersions of Nanocomposites: A Multiscale Analysis of 1H Pulsed Gradient Spin-Echo NMR Measurements

20030501

23/6/539 (Item 2 from file: 103)

06061292 PNNL

Title: Electrochemical sensors based on nanomaterials for environmental monitoring Publication Date: 20070501 Availability Date: 20071105

23/6/540 (Item 3 from file: 103)

06051381 NLN; RN07114475; TVI 3837 Title: Development and characterization of Al{sub 2}Cu and Ag{sub 2}Al nanoparticle dispersed water and ethylene glycol based nanofluid Publication Date: 20070515 Availability Date: 20071113

23/6/541 (Item 4 from file: 103)

05976226 GBN; RN07101740; TVI 3834 Title: Nano-characterization of a nafion thin film in air and in water by atomic force microscopy Publication Date: 20070415 Availability Date: 20070927

23/6/542 (Item 5 from file: 103)

05972042 NLN; RN07096830; TVI 3833 Title: Nanosized spinel NiFe{sub 2}O{sub 4}: A novel material for the detection of liquefied petroleum gas in air Publication Date: 20030928 Availability Date: 20070924

23/6/543 (Item 6 from file: 103)

05870395 CLA; RN07062984; TVI 0705; CLA-0705000013 Title: Remediation of soil contaminated with pyrene using ground nanoscale zero-valent iron Publication Date: 20070215 Availability Date: 20070716

23/6/545 (Item 8 from file: 103)

05726606 FR; RN07031348; TVI 0703 Title: Session 6: Nano-sized Nitrogen-Containing WO{sub 3}-TiO{sub 2} Composite Powders: Synthesis, Characterization, photo-catalysis and Potential Applications in Air Purification Conference title: Conference: 13. international congress on catalysis

Publication Date: 20040701 Availability Date: 20070416

23/6/547 (Item 10 from file: 103)

05478204 GB; RN06001198; TVI 0511 Title: Synthesis and characterization of nanocrystalline MnFe{sub 2}O{sub 4}: advances in thermochemical water splitting Publication Date: 20051101 Availability Date: 20060216

23/6/548 (Item 11 from file: 103)

05229280 LLNL Title: Optical properties of silicon nanoparticles in the presence of water: A first principles theoretical analysis Publication Date: 20040408 Availability Date: 20050417

23/6/551 (Item 14 from file: 103)

05013905 INIS Title: Electron transport in nanometer GaAs structure under radiation exposure; Ehlektronnyj transport v nanometrovykh GaAs strukturakh pri radiatsionnom vozdejstvii Publication Date: 20020101 Availability Date: 20031222

23/6/552 (Item 15 from file: 103)

04836151 INIS Title: Analysis of the nano-scale structure of a natural clayey soil using the small angle neutron scattering method Conference title: 4. conference on nuclear science and engineering in Australia. Theme: A new nuclear century: ANA 2001 Publication Date: 20010701 Availability Date: 20020902

23/6/554 (Item 2 from file: 245)

064518 Temperature Effects on the Transport of Water, Uncharged and Charged Solutes across Polymeric Nanofiltration Membranes

2007

23/6/555 (Item 3 from file: 245)

063980 Controlling Biofouling Potential of Nanofiltration Membranes by Surface Water: A New On- line Monitoring Tool 2006

23/6/556 (Item 4 from file: 245)

060677 Role of Pore Size Distribution in the Transport of Water Contaminants through Nanofiltration Membranes 2004

23/6/557 (Item 5 from file: 245)

057559 Biostability Characterization in a Full-Scale Nanofiltration Water Treatment System 2003

23/6/558 (Item 6 from file: 245)

056128 Evaluation of the Port Hueneme Demonstration Plant: An Analysis of 1 MGD Reverse Osmosis, Nanofiltration and Electrodialysis Reversal Plants Run Under Essentially Identical Conditions; Water Treatment Technology Program Report No. 65 2001

23/6/559 (Item 1 from file: 293)

0000455595 IP Accession No: 200711-C4-C-142495; 200711-C4-D-142495; 200711-C4-P- 142495

Synthesis and characterization of nanoparticle Co3O4, CuO and NiO catalysts prepared by physical and chemical methods to minimize air pollution

Publication Date: 2007

23/6/560 (Item 2 from file: 293)

0000440869 IP Accession No: 200709-D1-P-128455 SYNTHESIS AND CHARACTERIZATION OF WATER SOLUBLE AND AMPHIPHILIC POLY(ETHYLENE GLYCOL) COATED MAGNETITE NANOPARTICLES

Publication Date: 2007

23/6/561 (Item 3 from file: 293)

0000438870 IP Accession No: 200709-E7-C-127498; 200709-E7-D-127498; 200709-E7-P- 127498 Research on separation of rinse water of nickel electroplating with nano-filtration membrane.

Publication Date: 2007

23/6/563 (Item 5 from file: 293)

0000406656 IP Accession No: 200707-G1-C-095767; 200707-G1-D-095767; 200707-G1-P- 095767 Analysis of the Surface Adsorbed Organics of Nanosized TiO2 Photocatalyst with High Visible- light Photocatalysis Activity by Ultrasonic Treatment under Water and Ethanol Solution

Publication Date: 2007

23/6/564 (Item 6 from file: 293)

0000404161 IP Accession No: 200707-G1-C-099611; 200707-G1-D-099611; 200707-G1-P- 099611 Mechanism Analysis and Preparation of Core-shell TiO2/SiO2 Nanoparticles by H2/Air Flame Combustions

Publication Date: 2007

23/6/565 (Item 7 from file: 293)

0000380315 IP Accession No: 200703-G1-P-038985 Ageing Analysis of the Bipolar Plates Fabricated from Aromatic Polydisulfide/Graphite Nanocomposite in Simulated PEMFC Environment

Publication Date: 2006

23/6/566 (Item 8 from file: 293)

0000338882 IP Accession No: 200612-D1-P-32689 Preparation and Characterization of Nit+-Montmorillonite/ Polyvinyl Alcohol Water-Soluble Nanocomposite Film

Publication Date: 2005

23/6/567 (Item 9 from file: 293)

0000313891 IP Accession No: 200605-C4-C-09188 Analysis of Nano-Aluminum Particle Dust Cloud Combustion in Different Oxidizer Environments

Publication Date: 2005

23/6/568 (Item 10 from file: 293)

0000308925 IP Accession No: 200603-D1-C-05310 DEVELOPMENT AND CHARACTERIZATION OF NANOCRYSTALLINE TiO2 AND ZrO2 DISPERSED WATER AND ETHYLENE GLYCOL BASED NANOFLUID

Publication Date: 2005

23/6/569 (Item 11 from file: 293)

0000279418 IP Accession No: 200405-C4-C-0528 A room-temperature TiO sub 2 -nanotube hydrogen sensor able to self-clean photoactively from environmental contamination.

Publication Date: 2004

23/6/570 (Item 1 from file: 315)

685685 0000685685

Preparation and characterization of anodized Pt-TiO(sub 2) nanotube arrays for water splitting

Original Title: Vorbereitung und Charakterisierung von anodisierten Pt-TiO(sub 2)- Nanoroehrchenanordnungen fuer die Spaltung von Wasser

23/6/571 (Item 2 from file: 315)

667020 0000667020

Separation and purification of functionalised water-soluble multi-walled carbon nanotubes by flow field-flow fractionation Original Title: Trennung und Reinigung funktionalisierter wasserloeslicher Multiwand-Kohlenstoff- Nanoroehren durch Fluss-Feld-Fluss-Fraktionierung

23/6/576 (Item 1 from file: 323)

00997347 Title: CHARACTERIZATION OF CARBON NANOTUBES UPON RADIATION EXPOSURE

23/6/577 (Item 2 from file: 323)

00980160 Title: AGEING ANALYSIS OF THE BIPOLAR PLATES FABRICATED FROM AROMATIC POLYDISULFIDE/GRAPHITE NANOCOMPOSITE IN SIMULATED PEMFC ENVIRONMENT

23/6/578 (Item 3 from file: 323)

00977666 Title: PREPARATION AND CHARACTERIZATION OF SILVER NANOPARTICLES IN WATER-IN-OIL EMULSIONS

23/6/579 (Item 4 from file: 323)

00977664 Title: PREPARATION AND CHARACTERIZATION OF TITANIUM DIOXIDE NANOPARTICLES IN WATER-IN-OIL EMULSIONS

23/6/580 (Item 5 from file: 323)

00956570 Title: PREPARATION AND CHARACTERIZATION OF NI2+- MONTMORILLONITE/POLYVINYL ALCOHOL WATER-SOLUBLE NANOCOMPOSITE FILM

23/6/581 (Item 6 from file: 323)

00888097 Title: PREPARATION AND CHARACTERIZATION OF NANOFILTRATION MEMBRANES FABRICATED FROM POLY(AMIDESULFONAMIDE)S AND APPLICATION IN WATER-OIL SEPARATION

23/6/582 (Item 7 from file: 323)

00879695 Title: PREPARATION AND CHARACTERIZATION OF NANOFILTRATION MEMBRANES FABRICATED FROM POLYAMIDESULFONAMIDE, AND THEIR APPLICATION IN WATER -OIL SEPARATION

23/6/583 (Item 1 from file: 636)

05879396 Supplier Number: 122824297 (USE FORMAT 7 FOR FULLTEXT)

Nano Bisaisui Air Freshener MANUFACTURER: Matsushita Electrics CATEGORY: 416 - Deodorizers & Air Fresheners.(Brief Article) Sept 6 , 2004 Word Count: 36

23/6/585 (Item 3 from file: 636)

05079459 Supplier Number: 78408401 (USE FORMAT 7 FOR FULLTEXT)

Big plans on a small scale -- NSF funds centers for nanoscale research; Will advance information, medical, manufacturing and environmental technologies.

Sept 19 , 2001 Word Count: 991

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