DOCSLIB.ORG

An in Situ Template Route for Fabricating Metal Chalcogenide Hollow Spherical Assemblies Sonochemically

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
An in Situ Template Route for Fabricating Metal Chalcogenide Hollow Spherical Assemblies Sonochemically FULL PAPER An in situ Template Route for Fabricating Metal Chalcogenide Hollow Spherical Assemblies Sonochemically Shu Xu,[a] Hui Wang,[a] Jun-Jie Zhu,*[a] Xin-Quan Xin,[a] and Hong-Yuan Chen[a] Keywords: Sonochemistry / Nanostructures / Self-assembly / Metal chalcogenides / Hollow spheres An ultrasound-assisted in situ template approach has been tion of the intermediate templates and in the crystal-growth developed for fabricating a series of nanoscale metal chalco- process. This approach provides a convenient and efficient genides in the form of well-defined hollow spherical assem- one-step pathway to the large-scale fabrication of hollow blies. These hollow spherical assemblies have well-con- spherical nanostructures. It also represents a new demonstra- trolled dimensions and are composed of uniform nanopart- tion of sonochemical effects on the formation and assembly icles. Initially, metal hydroxide particles self-assemble into of crystalline particles on the nanometer scale. spherical templates generated in situ, and subsequent sur- face crystal growth leads to hollow spherical structures. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Ultrasound irradiation plays a critical role both in the forma- Germany, 2004) Introduction of a polymer or some other material is prepared as a tem- plate; then, assembly is carried out on the surface of the Much attention has been devoted lately to developing core to obtain a coreϪshell structure; finally, the core is methods for preparing, connecting, and assembling semi- removed to form the hollow structure. A widely adopted conductor nanocrystals. The well-ordered assemblies, un- and quickly developed template method is the LBL self- like nanoparticles or single crystals, have new properties assembly technique, which is based on the use of electro- suitable for building fine powders or other functional mate- static interactions or hydrogen bonding between alternate rials. Over the last decades the novel properties and appli- layers of materials deposited on a surface. This technique cations of these materials, including mesoporous structures, can be applied to the coating of colloids.[5,18,19] However, networks, coreϪshell spherical materials, and a series of only a few hollow spheres of silica, zeolite, and other [1Ϫ9] wire- or rod-like assemblies have been exhibited. Es- magnetic materials have been fabricated by using this strat- pecially the assembled hollow spherical materials are im- egy because of the difficulty in the removal of the template portant because of their many potential applications in cores. For this reason, we are still trying to find some new various fields of chemistry, biotechnology, and materials methods with the goal of avoiding the disassembly of the science. For example, they can be used for the transport, shell in the process of removing the cores to produce the controlled storage, and release of chemical and biological final hollow spherical materials, or of even generating hol- products such as drugs, for the protection of biologically low spherical structures directly without a coreϪshell step active macromolecules, and in the field of catalysis and wa- (Scheme 1). [10Ϫ13] ste removal. Until now, most methods for the fabri- Ultrasound waves that are intense enough to produce cation of inorganic materials with hollow spherical struc- cavitations can drive chemical reactions such as oxidation, tures were based on a number of well-developed techniques, reduction, dissolution, decomposition, and poly- such as the nozzle reaction system, emulsion/water extrac- merization.[22Ϫ33] Ultrasound irradiation has also been em- tion, layer-by-layer (LBL) self-assembly, and sacrificial ployed to prepare a series of polymer core/metal oxide shell [5,14Ϫ21] coreϪshell techniques. particles and a cadmium selenide hollow spherical Currently, the template-directed assembly of nanodimen- material.[9,22,26,34Ϫ36] In recent years, the sonochemical sional materials is arousing increasing interest due to its method has been proven to be convenient and effective in unique advantages in the control over shape, orientation, the fabrication of porous structures. It has been discovered and crystal growth. It usually takes three steps to prepare that the ultrasound wave has a strong effect on the congre- hollow spherical assemblies: first, a colloidal core consisting gation and self-assembly of nanoparticles. Gedanken’s group has established this procedure as a route to produce [a] State Key Laboratory of Coordination Chemistry, Department some tubular assemblies and a variety of mesoporous oxide of Chemistry, Nanjing University, [37Ϫ39] Nanjing 210093, P. R. China materials. The advantage of the application of ultra- E-mail: [email protected] sound irradiation to the synthesis of mesoporous materials Eur. J. Inorg. Chem. 2004, 4653Ϫ4659 DOI: 10.1002/ejic.200400242 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 4653 FULL PAPER S. Xu, H. Wang, J.-J. Zhu, X.-Q. Xin, H.-Y. Chen CdS, and CuS particles were estimated to be about 7 nm, 7 nm, and 10 nm, respectively. Scheme 1. Proposed mechanism for the synthesis of hollow- sphere materials is the significant reduction in fabrication time and the pos- Figure 1. Powder XRD pattern of hollow spherical assemblies: (a) sibility to induce the aggregation of nanoparticles into po- CdSe; (b) CdS; (c) CuS rous structures without destroying the micellar structure. Hence, this method provides an effective surface assembly route for the controllable synthesis of spatially structured XPS measurements supply further evidence for the com- materials. position and purity of the products. All peaks were cali- We have extended the sonochemical method to the syn- brated by using C(1s) (284.6 eV) as the reference. The two [40] thesis of hollow spherical nanostructural materials. An peaks located at 405.5 eV and 412.3 eV were assigned to in situ template route was developed for fabricating a series Cd(3d). The peaks at 54.5 eV, 162.2 eV, and 932 eV corre- of metal chalcogenide hollow spherical assemblies in an spond to Se(3d), S(2p), and Cu(2p), respectively. According aqueous system. It is a general approach for fabricating hol- to the measurements, the ratio Cd/Se is approximately 6:4, low spherical materials directly, which makes it possible to which shows that the sample of the CdSe assembly is rich avoid the step of removing the template core. in cadmium at the surface. The measurements also show that the ratio Cd/S is approximately 6:4 and the ratio Cu/S is approximately 1.1:1. Results and Discussion In the TEM images (Figure 2, a, b), uniform hollow CdSe spheres with an average diameter of 120 nm are ob- Characterization of Hollow-Sphere Assemblies served. These hollow spheres consist of spherical nanopart- icles about 5 nm in size. The HRTEM image (Figure 2, c) Cadmium selenide, cadmium sulfide, and copper sulfide of a single hollow sphere exhibits the clear crystalline lattice hollow spherical assemblies were prepared. To study the of CdSe particles on the spherical surface and the hollow properties and morphology of the products, characteri- inside can also be observed clearly. The SAED (Figure 2, zation techniques including powder XRD, TEM, XPS, d) recorded on a CdSe hollow sphere shows the presence of SAED, UV/Vis absorption and fluorescence spectroscopy clear diffraction rings, which correspond to the cubic phase were employed. of CdSe with polycrystalline nature. In Figure 3, uniform hollow CdS spheres with an average diameter of 120 nm are XRD, XPS Studies, and TEM Observations observed. The surface structure of the CdS spheres is the The X-ray diffraction patterns for the products are shown same as that of the hollow CdSe spheres assembled from in Figure 1. The diffraction peak in pattern (a) indicates nanoparticles about 5 nm in size. Figure 4 shows the TEM that the CdSe particles are crystallized in the pure cubic image of the CuS hollow spheres with diameters ranging phase (JCPDS No. 19-191), pattern (b) corresponds to the from 150 to 300 nm. These spheres are made up of CuS pure cubic phase CdS (JCPDS No.75-0581), and pattern (c) nanoparticles about 8 nm in size. The shell of the CuS belongs to pure CuS crystals (JCPDS No. 03-1090). No sphere is thinner than that of the hollow CdSe and CdS peaks of any other impurities were detected, indicating the spheres, so the hollow space inside is very distinct. The high purity of the products. According to the TEM images confirm that all the spheres for all three com- DebyeϪScherrer equation,[41] the average sizes of the CdSe, pounds are hollow. 4654 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim www.eurjic.org Eur. J. Inorg. Chem. 2004, 4653Ϫ4659 Metal Chalcogenide Hollow Spherical Assemblies FULL PAPER Optical Characterization The UV/Vis absorbance spectra of the prepared hollow spherical materials were measured and their correlative op- tical band gaps were calculated according to the following Equation, where A is a constant, α is the absorption coef- ficient, and m ϭ 3 for a direct and m ϭ 1 for an indirect transition.[42] m/2 α(ν) ϭ A·[hν/(2 Ϫ Eg)] The CdSe assembly has its absorbance peak at 350 nm. Its direct band gap is calculated to be 2.7 eV, which is much larger than the reported value for bulk CdSe (Eg ϭ 1.7 eV).[43] This band-gap value, which indicates the quan- tum size effect of this sample, equals that of the 7 nm quan- tum CdSe nanoparticles prepared. It offers further evidence that these spherical assemblies are made up of smaller nan- oparticles. The direct band gap of the hollow CdS assembl- ies is calculated to be 2.11 eV. The equation with m ϭ 1 is Figure 2. TEM and HRTEM images of the CdSe assemblies in the used for the indirect transition to the copper sulfide nano- presence of ammonia after sonication for 30 min (concentration of particles, since copper sulfide is a typical indirect semicon- NH3: 0.8 mol/L): (a, b) TEM images of the product, (c) HRTEM [44] image of an individual CdSe hollow-spherical assembly, (d) [inset ductor.
Load more

Recommended publications
  • (Oxy)Hydroxide Electrocatalysts for Water Oxidation Bryan R
    www.acsami.org Research Article Effect of Selenium Content on Nickel Sulfoselenide-Derived Nickel (Oxy)hydroxide Electrocatalysts for Water Oxidation Bryan R. Wygant, Anna H. Poterek, James N. Burrow, and C. Buddie Mullins* Cite This: ACS Appl. Mater. Interfaces 2020, 12, 20366−20375 Read Online ACCESS Metrics & More Article Recommendations *sı Supporting Information ABSTRACT: An efficient and inexpensive electrocatalyst for the oxygen evolution reaction (OER) must be found in order to improve the viability of hydrogen fuel production via water electrolysis. Recent work has indicated that nickel chalcogenide materials show promise as electrocatalysts for this reaction and that their performance can be further enhanced with the generation of ternary, bimetallic chalcogenides (i.e., Ni1−aMaX2); however, relatively few studies have investigated ternary chalcogenides created through the addition of a second chalcogen (i.e., NiX2−aYa). To address this, we fi studied a series of Se-modi ed Ni3S2 composites for use as OER electrocatalysts in alkaline solution. We found that the addition of Se results in the creation of Ni3S2/NiSe composites composed of cross-doped metal chalcogenides and show that the addition of 10% Se reduces the overpotential required to reach a current density of 10 mA/cm2 by 40 mV versus a pure nickel sulfide material. Chemical analysis of the composites’ surfaces shows a reduction in the amount of nickel oxide species with Se incorporation, which is supported by transmission electron microscopy; this reduction is correlated with a decrease in the OER overpotentials measured for these samples. Together, our results suggest that the incorporation of Se into Ni3S2 creates a more conductive material with a less-oxidized surface that is more electrocatalytically active and resistant to further oxidation.
    [Show full text]
  • The Influence of Sodium Hydroxide Concentration on the Phase, Morphology and Agglomeration of Cobalt Oxide Nanoparticles and Application As Fenton Catalyst
    Digest Journal of Nanomaterials and Biostructures Vol.14, No.4, October-December 2019, p. 1131-1137 THE INFLUENCE OF SODIUM HYDROXIDE CONCENTRATION ON THE PHASE, MORPHOLOGY AND AGGLOMERATION OF COBALT OXIDE NANOPARTICLES AND APPLICATION AS FENTON CATALYST E. L. VILJOENa,*, P. M. THABEDEa, M. J. MOLOTOa, K. P. MUBIAYIb, B. W. DIKIZAa aDepartment of Chemistry, Vaal University of Technology Private, Bag X021, Vanderbijlpark 1900, South Africa bSchool of Chemistry, University of the Witwatersrand, 1 Jan Smuts Avenue, Braamfontein Johannesburg 2000, South Africa The concentration of NaOH was varied from 0.2 M to 0.7 M during the preparation of the cobalt oxide/cobalt oxide hydroxide nanoparticles by precipitation and air oxidation. Cubic shaped and less well defined Co3O4 nanoparticles formed at 0.2 M NaOH. An increase in the NaOH concentration increased the number of well-defined cubic shaped nanoparticles. Agglomerated CoO(OH) particles with different shapes formed at the highest NaOH concentration. The cubic shaped Co3O4 nanoparticles were subsequently used as catalyst for the Fenton degradation of methylene blue and it was found that the least agglomerated nanoparticles were the most catalytically active. (Received June 25, 2019; Accepted December 6, 2019) Keywords: Cobalt oxide, Nanoparticles, Precipitation, pH, Fenton reaction 1. Introduction Controlling the size and the shape of nanoparticles using simple, inexpensive precipitation methods without sophisticated capping molecules, remains a challenge. Literature has indicated that the concentration of the base (pH) is an important parameter to control the size, shape and phase of metal oxide nanoparticles. Obodo et al.[1] used chemical bath deposition at atmospheric pressure and 70 °C to precipitate Co3O4 crystallites on a glass substrate and they showed that the crystallite sizes were larger at a higher pH of 12 in comparison to when a pH of 10 was used.
    [Show full text]
  • SODIUM HYDROXIDE @Lye, Limewater, Lyewater@
    Oregon Department of Human Services Office of Environmental Public Health (503) 731-4030 Emergency 800 NE Oregon Street #604 (971) 673-0405 Portland, OR 97232-2162 (971) 673-0457 FAX (971) 673-0372 TTY-Nonvoice TECHNICAL BULLETIN HEALTH EFFECTS INFORMATION Prepared by: ENVIRONMENTAL TOXICOLOGY SECTION OCTOBER, 1998 SODIUM HYDROXIDE @Lye, limewater, lyewater@ For More Information Contact: Environmental Toxicology Section (971) 673-0440 Drinking Water Section (971) 673-0405 Technical Bulletin - Health Effects Information Sodium Hydroxide Page 2 SYNONYMS: Caustic soda, sodium hydrate, soda lye, lye, natrium hydroxide CHEMICAL AND PHYSICAL PROPERTIES: - Molecular Formula: NaOH - White solid, crystals or powder, will draw moisture from the air and become damp on exposure - Odorless, flat, sweetish flavor - Pure solid material or concentrated solutions are extremely caustic, immediately injurious to skin, eyes and respiratory system WHERE DOES IT COME FROM? Sodium hydroxide is extracted from seawater or other brines by industrial processes. WHAT ARE THE PRINCIPLE USES OF SODIUM HYDROXIDE? Sodium hydroxide is an ingredient of many household products used for cleaning and disinfecting, in many cosmetic products such as mouth washes, tooth paste and lotions, and in food and beverage production for adjustment of pH and as a stabilizer. In its concentrated form (lye) it is used as a household drain cleaner because of its ability to dissolve organic solids. It is also used in many industries including glassmaking, paper manufacturing and mining. It is used widely in medications, for regulation of acidity. Sodium hydroxide may be used to counteract acidity in swimming pool water, or in drinking water. IS SODIUM HYDROXIDE NATURALLY PRESENT IN DRINKING WATER? Yes, because sodium and hydroxide ions are common natural mineral substances, they are present in many natural soils, in groundwater, in plants and in animal tissues.
    [Show full text]
  • Carbon Dioxide Capture from Atmospheric Air Using Sodium
    Environ. Sci. Technol. 2008, 42, 2728–2735 Carbon Dioxide Capture from Nearly all current research on CCS focuses on capturing CO2 from large, stationary sources such as power plants. Atmospheric Air Using Sodium Such plans usually entail separating CO2 from flue gas, compressing it, and transporting it via pipeline to be Hydroxide Spray sequestered underground. In contrast, the system described in this paper captures CO2 directly from ambient air (“air § capture”). This strategy will be expensive compared to capture JOSHUAH K. STOLAROFF, from point sources, but may nevertheless act as an important DAVID W. KEITH,‡ AND complement, since CO emissions from any sector can be GREGORY V. LOWRY*,† 2 captured, including emissions from diffuse sources such as Chemical and Petroleum Engineering, University of Calgary, aircraft or automobiles, where on-board carbon capture is and Departments of Civil and Environmental Engineering very difficult and the cost of alternatives is high. Additionally, and Engineering and Public Policy, Carnegie Mellon in a future economy with low carbon emissions, air capture University, Pittsburgh, Pennsylvania 15213 might be deployed to generate negative net emissions (1). This ability to reduce atmospheric CO2 concentrations faster Received October 15, 2007. Revised manuscript received than natural cycles allow would be particularly desirable in February 05, 2008. Accepted February 06, 2008. scenarios where climate sensitivity is on the high end of what is expected, resulting in unacceptable shifts in land usability and stress to ecosystems. In contrast to conventional carbon capture systems for Previous research has shown that air capture is theoreti- cally feasible in terms of thermodynamic energy require- power plants and other large point sources, the system described ments, land use (2), and local atmospheric transport of CO2 in this paper captures CO2 directly from ambient air.
    [Show full text]
  • Exposure to Potassium Hydroxide Can Cause Headache, Eye Contact Dizziness, Nausea and Vomiting
    Right to Know Hazardous Substance Fact Sheet Common Name: POTASSIUM HYDROXIDE Synonyms: Caustic Potash; Lye; Potassium Hydrate CAS Number: 1310-58-3 Chemical Name: Potassium Hydroxide (KOH) RTK Substance Number: 1571 Date: May 2001 Revision: January 2010 DOT Number: UN 1813 Description and Use EMERGENCY RESPONDERS >>>> SEE LAST PAGE Potassium Hydroxide is an odorless, white or slightly yellow, Hazard Summary flakey or lumpy solid which is often in a water solution. It is Hazard Rating NJDOH NFPA used in making soap, as an electrolyte in alkaline batteries and HEALTH - 3 in electroplating, lithography, and paint and varnish removers. FLAMMABILITY - 0 Liquid drain cleaners contain 25 to 36% of Potassium REACTIVITY - 1 Hydroxide. CORROSIVE POISONOUS GASES ARE PRODUCED IN FIRE DOES NOT BURN Reasons for Citation Hazard Rating Key: 0=minimal; 1=slight; 2=moderate; 3=serious; f Potassium Hydroxide is on the Right to Know Hazardous 4=severe Substance List because it is cited by ACGIH, DOT, NIOSH, NFPA and EPA. f Potassium Hydroxide can affect you when inhaled and by f This chemical is on the Special Health Hazard Substance passing through the skin. List. f Potassium Hydroxide is a HIGHLY CORROSIVE CHEMICAL and contact can severely irritate and burn the skin and eyes leading to eye damage. f Contact can irritate the nose and throat. f Inhaling Potassium Hydroxide can irritate the lungs. SEE GLOSSARY ON PAGE 5. Higher exposures may cause a build-up of fluid in the lungs (pulmonary edema), a medical emergency. FIRST AID f Exposure to Potassium Hydroxide can cause headache, Eye Contact dizziness, nausea and vomiting.
    [Show full text]
  • Aluminium Distearate, Aluminium Hydroxide Acetate, Aluminium Phosphate and Aluminium Tristearate
    The European Agency for the Evaluation of Medicinal Products Veterinary Medicines Evaluation Unit EMEA/MRL/393/98-FINAL April 1998 COMMITTEE FOR VETERINARY MEDICINAL PRODUCTS ALUMINIUM DISTEARATE, ALUMINIUM HYDROXIDE ACETATE, ALUMINIUM PHOSPHATE AND ALUMINIUM TRISTEARATE SUMMARY REPORT 1. Aluminium is an ubiquitous element in the environment. It is present in varying concentrations in living organisms and in foods. Aluminium compounds are widely used in veterinary and human medicine. Other uses are as an analytical reagent, food additives (e.g. sodium aluminium phosphate as anticaking agent) and in cosmetic preparations (aluminium chloride). Aluminium distearate is used for thickening lubricating oils. Aluminium hydroxide acetate and phosphate are antacids with common indications in veterinary medicine: gastric hyperacidity, peptic ulcer, gastritis and reflux esophagitis. A major use of antacids in veterinary medicine is in treatment and prevention of ruminal acidosis from grain overload, adsorbent and antidiarrheal. The dosage of aluminium hydroxide is 30 g/animal in cattle and 2 g/animal in calves and foals. Gel preparations contain approximately 4% aluminium hydroxide. Aluminium potassium sulphate is used topically as a antiseptic, astringent (i.e. washes, powders, and ‘leg tighteners’ for horses (30 to 60 g/animal) and antimycotic (1% solution for dipping or spraying sheeps with dermatophilus mycotic dermatitis). In cattle it is occasionally used for stomatitis and vaginal and intrauterine therapy at doses of 30 to 500 g/animal. In human medicine, aluminium hydroxide-based preparations have a widespread use in gastroenterology as antacids (doses of about 1 g/person orally) and as phosphate binders (doses of about 0.8 g/person orally) in patients an impairment of renal function.
    [Show full text]
  • Safety Assessment of Ammonia and Ammonium Hydroxide As Used in Cosmetics
    Safety Assessment of Ammonia and Ammonium Hydroxide as Used in Cosmetics Status: Final Report Release Date: February 15, 2018 Panel Date: December 4-5, 2017 . The 2017 Cosmetic Ingredient Review Expert Panel members are: Chair, Wilma F. Bergfeld, M.D., F.A.C.P.; Donald V. Belsito, M.D.; Ronald A. Hill, Ph.D.; Curtis D. Klaassen, Ph.D.; Daniel C. Liebler, Ph.D.; James G. Marks, Jr., M.D.; Ronald C. Shank, Ph.D.; Thomas J. Slaga, Ph.D.; and Paul W. Snyder, D.V.M., Ph.D. The CIR Executive Director is Bart Heldreth, Ph.D. This report was prepared by Wilbur Johnson, Jr., M.S., Senior Scientific Analyst. © Cosmetic Ingredient Review 1620 L STREET, NW, SUITE 1200 ◊ WASHINGTON, DC 20036-4702 ◊ PH 202.331.0651 ◊ FAX 202.331.0088 ◊ [email protected] ABSTRACT: The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) reviewed the safety of Ammonia and Ammonium Hydroxide, which function as pH adjusters in cosmetic products. Ammonium Hydroxide is also reported to function as a denaturant. The Panel reviewed data relevant to the safety of these ingredients and concluded that Ammonia and Ammonium Hydroxide are safe as used in hair dyes and colors and safe in cosmetics applied directly to the skin in the present practices of use and concentration described in the safety assessment, when formulated to be non-irritating. INTRODUCTION The safety of Ammonia and Ammonium Hydroxide in cosmetics is reviewed in this Cosmetic Ingredient Review (CIR) safety assessment. According to the web-based International Cosmetic Ingredient Dictionary and Handbook (wINCI Dictionary), both ingredients are reported to function as pH adjusters in cosmetic products.1 Additionally, Ammonia is reported to function as an external analgesic and fragrance ingredient, and Ammonium Hydroxide is reported to function as a denaturant in cosmetic products.
    [Show full text]
  • Temperature Dependent Etching of (100) and (110) Silicon in Naoh and in Tetramethyl-Ammonium Hydroxide
    Sensors and Materials, Vol. 14, No. 8 (2002) 415-428 MYUTokyo S&M0501 Temperature Dependent Etching of (100) and (110) Silicon in NaOH and in Tetramethyl-Ammonium Hydroxide Vladimir F. Kleptsyn and Johannes G. Smits Department of Electrical and Computer Engineering College of Engineering, Boston University 8 Saint Mary's Street, Boston MA 02215, U.S.A. (Received February2, 2002: accepted December 4, 2002) Key words: silicon, wet etching, sodium hydroxide, tetramethyl ammonium hydroxide The etch rates for single crystal silicon wafers in NaOH and tetramethyl-ammonium ° hydroxide (TMAH) have been measured in the temperature range from 28 C to 80 °C and activation energies of about 0.68 and 0.57 eV for NaOH and TMAH respectively for the (100) plane are observed. A qualitative model of the etching of silicon planes in NaOH and TMAH is presented. 1. Introduction Orientation dependent etching of silicon has been studied in the past using aqueous solutions of alkali hydroxides. It is a very useful technique to fabricate microstructures in silicon. WeirauchC 1l studied anisotropic etching of single crystal silicon spheres and wafers using 10 M KOH as the etchant. The etch rates along several vector directions were measured and the slowest etching planes were foundusing a single crystal sphere. Using these data, a method was developed to predict the angles of inclination for surfaces of different orientations. The angles of inclination correlated well with the data collected from etching a single crystal sphere. Kendall et al. c2i proposed the new wagon wheel method to measure anisotropic etching. So far several studies have been carried out to understand the mechanism of etching and, based on the experimental data obtained, several 3 models for etching have been proposed.
    [Show full text]
  • Chemical Engineering Vocabulary
    Chemical Engineering Vocabulary Maximilian Lackner Download free books at MAXIMILIAN LACKNER CHEMICAL ENGINEERING VOCABULARY Download free eBooks at bookboon.com 2 Chemical Engineering Vocabulary 1st edition © 2016 Maximilian Lackner & bookboon.com ISBN 978-87-403-1427-4 Download free eBooks at bookboon.com 3 CHEMICAL ENGINEERING VOCABULARY a.u. (sci.) Acronym/Abbreviation referral: see arbitrary units A/P (econ.) Acronym/Abbreviation referral: see accounts payable A/R (econ.) Acronym/Abbreviation referral: see accounts receivable abrasive (eng.) Calcium carbonate can be used as abrasive, for example as “polishing agent” in toothpaste. absorbance (chem.) In contrast to absorption, the absorbance A is directly proportional to the concentration of the absorbing species. A is calculated as ln (l0/l) with l0 being the initial and l the transmitted light intensity, respectively. absorption (chem.) The absorption of light is often called attenuation and must not be mixed up with adsorption, an effect at the surface of a solid or liquid. Absorption of liquids and gases means that they diffuse into a liquid or solid. abstract (sci.) An abstract is a summary of a scientific piece of work. AC (eng.) Acronym/Abbreviation referral: see alternating current academic (sci.) The Royal Society, which was founded in 1660, was the first academic society. acceleration (eng.) In SI units, acceleration is measured in meters/second Download free eBooks at bookboon.com 4 CHEMICAL ENGINEERING VOCABULARY accompanying element (chem.) After precipitation, the thallium had to be separated from the accompanying elements. TI (atomic number 81) is highly toxic and can be found in rat poisons and insecticides. accounting (econ.) Working in accounting requires paying attention to details.
    [Show full text]
  • Oxychem Sodium Hypochlorite Handbook
    TABLE OF CONTENTS OxyChem Sodium Hypochlorite Handbook Introduction 2 Foreword Properties 3 This handbook outlines recommended methods for handling, storing, and using sodium hypochlorite. It also Concentration Terminology 5 includes information on the manufacture, physical properties, safety considerations and analytical methods for testing sodium Manufacturing 6 hypochlorite. Additional information and contacts can be found at www.oxychem.com Handling and Storage 9 Safety Handling 11 Unloading Tank Trucks 14 Physical Property Data 16 Methods of Analysis 18 Typical Storage Tank Installation 23 Important: The information presented herein, while not guaranteed, was prepared by technical personnel and is true and accurate to the best of our knowledge. NO WARRANTY OF MERCHANTABILITY OR OF FITNESS FOR A PARTICULAR PURPOSE, OR WARRANTY OR GUARANTY OF ANY OTHER KIND, EXPRESS OR IMPLIED, IS MADE REGARDING PERFORMANCE, SAFETY, SUITABILITY, STABILITY OR OTHERWISE. This information is not intended to be all-inclusive as to the manner and conditions of use, handling, storage, disposal and other factors that may involve other or additional legal, environmental, safety or performance considerations, and Occidental Chemical Corporation assumes no liability whatsoever for the use of or reliance upon this information. While our technical personnel will be happy to respond to questions, safe handling and use of the product remains the responsibility of the customer. No suggestions for use are intended as, and nothing herein shall be construed as, a recommendation to infringe any existing patents or to violate any Federal, State, local or foreign laws. INTRODUCTION This handbook provides information Sodium hypochlorite solutions have In 1798, Tennant of England prepared concerning sodium hypochlorite or attained widespread use in bleaching a solution of calcium hypochlorite by bleach, solutions.
    [Show full text]
  • Carbon Dioxide Capture Using Sodium Hydroxide Solution: Comparison Between an Absorption Column and a Membrane Contactor
    Carbon dioxide capture using sodium hydroxide solution: comparison between an absorption column and a membrane contactor Dissertation presented by Nicolas CAMBIER for obtaining the master's degree in Chemical and Materials Engineering Supervisor Patricia LUIS ALCONERO Tutor Israel RUIZ SALMON Readers Juray DE WILDE, Joris PROOST Academic year 2016-2017 Acknowledgements Before beginning this report, I would like to address my acknowledgements to the people who helped me throughout the realisation of my master thesis. First of all, nothing would have been possible without the support and advices of my promoter, the professor Patricia Luis. The working environment provided by her team and the meetings along the year were good opportunities to evolve for the best. Secondly, I would like to thank Israel Ruiz Salmon who was a major actor of my work. He always helped me with my numerous questions and uncertainties. Without him, I certainly would not have managed to overcome the numerous challenges encountered during this work. His precious advices and corrections are certainly what helped me to finish this master thesis. For their help with the preparation of solutions and in the lab, I thank Luc Wautier, Frédéric Van Wonterghem, Ronny Santoro and Nadine Deprez. In addition, I would like to express my gratitude to Professors J. De Wilde and J. Proost who have accepted to be the readers of this thesis. List of symbols Symbols Signification Units 푎 Specific area of packing per unit volume of column m2⁄m³ 퐴 Cross sectional area of the column m²
    [Show full text]
  • Corrosion Control Chemical (Sodium Hydroxide)
    CORROSION CONTROL CHEMICAL – SODIUM HYDROXIDE ENVIRONMENT DIVISION Frequently Asked Questions Q: What is a corrosion control chemical? A: A chemical that either alters the treated water chemistry or interacts with the surface of metallic materials in the water distribution system to inhibit corrosion and prevent the formation of soluble lead compounds. Q: Why is sodium hydroxide used in drinking water? A: Sodium hydroxide is used as a pH adjusting chemical in the treatment of drinking water to control the corrosion of metals such as lead from pipes into the drinking water. Q: How does sodium hydroxide work? A: Sodium hydroxide is used in the treatment of drinking water to raise the pH of the water to a level that minimizes the corrosion. Raising the pH remains one of the most effective methods for reducing lead corrosion and minimizing lead levels in drinking water. Q: Is it safe to drink my water if sodium hydroxide is added? A: Sodium hydroxide use as a corrosion inhibitor is listed in NSF/ANSI Standard 60. These standards have been designed to safeguard drinking water by ensuring that additives meet minimum health effects requirements and thus are safe for use in drinking water. (Health Canada – www.hc-sc.gc.ca). Q: Why is sodium hydroxide the best choice as a corrosion inhibitor? A: Sodium hydroxide was selected due to the chemistry of the City of Thunder Bay’s raw source water (Lake Superior) and conditions in the distribution system (pipes). The pristine raw water from Lake Superior is very “soft” with little buffering capacity; the water may leach minerals and contaminants from whatever material it comes into contact with.
    [Show full text]