Generation of Electron Deficient Carbodiimides and Their
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Polycarbodiimides As Classification-Free and Easy to Use Crosslinkers for Water-Based Coatings
White paper Polycarbodiimides as classification-free and easy to use crosslinkers for water-based coatings By Dr. A.J. Derksen, Stahl International bv, The Netherlands Polycarbodiimides (CDl) selectively react with carboxylic acid (–COOH) groups in polymer chains. This type of crosslinking reaction results in a classic 3D polymer-crosslinker network. Compared to polyisocyanates, polycarbodiimides are much less sensitive to presence of water and able to achieve long pot lives. Due to the high reactivity, curing with CDI type crosslinkers can be done under room temperature or typical oven conditions used for drying of applied coatings. In addition to standard CDI crosslinker chemistry, on offer is also a range of dual reactivity CDI crosslinkers. A second type of reactive groups is attached to the polycarbodiimide in this range. Upon curing, this crosslinker not only reacts with the –COOH groups in the polymer chains, but also two of the reactive groups attached to the separate CDI molecules can couple to form an even denser network structure. Building further on the success of these polycarbodiimide crosslinkers, VOC-free polycarbodiimides, in aqueous delivery form, were introduced, which give extreme long pot lives. 1. Introduction when dealing with flexible substrates. A high level of crosslinking Crosslinking is widely practiced in nearly all the coating may be acceptable for hard coatings on rigid substrates, but industries in order to improve the performance of the coating. low levels may be best for soft coatings on extensible, flexible These improvements include wear, abrasion and chemical substrates such as rubber and leather. An important crosslinking resistances and toughness1. The improved performance originates system for aqueous resins involves the use of water-dispersible from the formation of a continuous three-dimensional network, oligomeric polyisocyanates. -
Origins of Life: Transition from Geochemistry to Biogeochemistry
December 2016 Volume 12, Number 6 ISSN 1811-5209 Origins of Life: Transition from Geochemistry to Biogeochemistry NITA SAHAI and HUSSEIN KADDOUR, Guest Editors Transition from Geochemistry to Biogeochemistry Staging Life: Warm Seltzer Ocean Incubating Life: Prebiotic Sources Foundation Stones to Life Prebiotic Metal-Organic Catalysts Protometabolism and Early Protocells pub_elements_oct16_1300&icpms_Mise en page 1 13-Sep-16 3:39 PM Page 1 Reproducibility High Resolution igh spatial H Resolution High mass The New Generation Ion Microprobe for Path-breaking Advances in Geoscience U-Pb dating in 91500 zircon, RF-plasma O- source Addressing the growing demand for small scale, high resolution, in situ isotopic measurements at high precision and productivity, CAMECA introduces the IMS 1300-HR³, successor of the internationally acclaimed IMS 1280-HR, and KLEORA which is derived from the IMS 1300-HR³ and is fully optimized for advanced U-Th-Pb mineral dating. • New high brightness RF-plasma ion source greatly improving spatial resolution, reproducibility and throughput • New automated sample loading system with motorized sample height adjustment, significantly increasing analysis precision, ease-of-use and productivity • New UV-light microscope for enhanced optical image resolution (developed by University of Wisconsin, USA) ... and more! Visit www.cameca.com or email [email protected] to request IMS 1300-HR³ and KLEORA product brochures. Laser-Ablation ICP-MS ~ now with CAMECA ~ The Attom ES provides speed and sensitivity optimized for the most demanding LA-ICP-MS applications. Corr. Pb 207-206 - U (238) Recent advances in laser ablation technology have improved signal 2SE error per sample - Pb (206) Combined samples 0.076121 +/- 0.002345 - Pb (207) to background ratios and washout times. -
Reactivity and Structural Diversity in the Reaction Of
Reactivity and Structural Diversity in the Reaction of Guanidine 1,5,7-Triazabicyclo[4.4.0]dec-5-ene with CO 2 , CS 2 , and Other Heterocumulenes Niklas von Wolff, Claude Villiers, Pierre Thuéry, Guillaume Lefèvre, Michel Ephritikhine, Thibault Cantat To cite this version: Niklas von Wolff, Claude Villiers, Pierre Thuéry, Guillaume Lefèvre, Michel Ephritikhine, etal.. Reactivity and Structural Diversity in the Reaction of Guanidine 1,5,7-Triazabicyclo[4.4.0]dec-5-ene with CO 2 , CS 2 , and Other Heterocumulenes. European Journal of Organic Chemistry, Wiley-VCH Verlag, 2017, 2017, pp.676-686. 10.1002/ejoc.201601267. cea-01447886 HAL Id: cea-01447886 https://hal-cea.archives-ouvertes.fr/cea-01447886 Submitted on 27 Jan 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Reactivity and Structural Diversity in the Reaction of the TBD Guanidine with CO2, CS2 and Other Heterocumulenes Niklas von Wolff,[a] Claude Villiers,[a] Pierre Thuéry,[a] Guillaume Lefèvre,[a] Michel Ephritikhine*[a] and Thibault Cantat*[a] Abstract: The guanidine 1,5,7-triazabicyclo[4.4.0]dec-5-ene -
Dimethyl Sulfoxide Oxidation of Primary Alcohols
Western Michigan University ScholarWorks at WMU Master's Theses Graduate College 8-1966 Dimethyl Sulfoxide Oxidation of Primary Alcohols Carmen Vargas Zenarosa Follow this and additional works at: https://scholarworks.wmich.edu/masters_theses Part of the Chemistry Commons Recommended Citation Zenarosa, Carmen Vargas, "Dimethyl Sulfoxide Oxidation of Primary Alcohols" (1966). Master's Theses. 4374. https://scholarworks.wmich.edu/masters_theses/4374 This Masters Thesis-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Master's Theses by an authorized administrator of ScholarWorks at WMU. For more information, please contact [email protected]. DIMETHYL SULFOXIDE OXIDATION OF PRIMARY ALCOHOLS by Carmen Vargas Zenarosa A thesis presented to the Faculty of the School of Graduate Studies in partial fulfillment of the Degree of Master of Arts Western Michigan University Kalamazoo, Michigan August, 1966 ACKNOWLEDGMENTS The author wishes to express her appreciation to the members of her committee, Dr, Don C. Iffland and Dr. Donald C, Berndt, for their helpful suggestions and most especially to Dr, Robert E, Harmon for his patience, understanding, and generous amount of time given to insure the completion of this work. Appreciation is also expressed for the assistance given by her. colleagues. The author acknowledges the assistance given by the National Institutes 0f Health for this research project. Carmen Vargas Zenarosa ii TABLE OF CONTENTS Page -
Carbenes, Heteroaryl(Trifluoromethyl)Carbenes and Phenylbis(Trifluoromethyl)Carbenes
University of Nevada, Reno Matrix Isolation of Aryl(trifluoromethyl)carbenes, Heteroaryl(trifluoromethyl)carbenes and Phenylbis(trifluoromethyl)carbenes A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemistry by Pei Wang Dr. Robert S. Sheridan/Dissertation Advisor August, 2015 THE GRADUATE SCHOOL We recommend that the dissertation prepared under our supervision by PEI WANG Entitled Matrix Isolation Of Aryl(Trifluoromethyl)Carbenes, Heteroaryl(Trifluoromethyl)Carbenes And Phenylbis(Trifluoromethyl)Carbenes be accepted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Dr. Robert S. Sheridan, Advisor Dr. Kent M Ervin, Committee Member Dr. Chris Jeffrey, Committee Member Dr. Paula J Noble, Committee Member Dr. W. Patrick Arnott, Graduate School Representative David W. Zeh, Ph. D., Dean, Graduate School August, 2015 i Abstract We have isolated and studied 2-naphthyl(trifluoromethyl)carbene, 1- naphthyl(trifluoromethyl)carbene, 4-pyridyl (trifluoromethyl)carbene, 2-pyridyl (trifluoromethyl)carbene, 3-pyridyl (trifluoromethyl)carbene, 3-bromo-5-pyridyl (trifluoromethyl)carbene, meta-phenylbis(trifluoromethyl)carbene and para- phenylbis(trifluoromethyl)carbene in low temperature matrices for the first time. The naphthyl(trifluoromethyl)carbenes are photostable and have triplet ground states in matrices as most of the other studied ary(trifluoromethyl)carbenes. The 1- and 2- naphthyl(trifluoromethyl)diazirines, the precursors of 1- and 2- naphthyl(trifluoromethyl)carbenes, have dissimilar geometric structures leading to different UV/Vis absorptions. In the studied pyridyl(trifluoromethyl)carbenes, 4- pyridyl(trifluoromethyl)carbene was the most stable one in matrice: no photoproduct from 4- pyridyl(trifluoromethyl)carbene was observed. However, we obtained a small amount of photoproducts of 2 - pyridyl(trifluoromethyl)carbene, even though the result was not repeatable. -
The Importance of Reaction Conditions on the Chemical Structure of N,O-Acylated Chitosan Derivatives
molecules Article The Importance of Reaction Conditions on the Chemical Structure of N,O-Acylated Chitosan Derivatives Agnieszka Piegat 1,* , Agata Goszczy ´nska 1, Tomasz Idzik 2 and Agata Niemczyk 1 1 West Pomeranian University of Technology Szczecin, Faculty of Chemical Technology and Engineering, Polymer Institute, Division of Functional Materials and Biomaterials, 45 Piastow Ave, 70-311 Szczecin, Poland 2 West Pomeranian University of Technology Szczecin, Faculty of Chemical Technology and Engineering, Department of Organic and Physical Chemistry, 42 Piastow Ave, 71-065 Szczecin, Poland * Correspondence: [email protected]; Tel.: +48-91-449-44-55 Academic Editor: Massimiliano Fenice Received: 16 July 2019; Accepted: 21 August 2019; Published: 22 August 2019 Abstract: The structure of acylated chitosan derivatives strongly determines the properties of obtained products, influencing their hydrodynamic properties and thereby their solubility or self-assembly susceptibility. In the present work, the significance of slight changes in acylation conditions on the structure and properties of the products is discussed. A series of chitosan-acylated derivatives was synthesized by varying reaction conditions in a two-step process. As reaction media, two diluted acid solutions—i.e., acetic acid and hydrochloric acid)—and two coupling systems—i.e., 1-ethyl-3-(3-dimethyl-aminopropyl)-1-carbodiimide hydrochloride (EDC) and N–hydroxysulfosuccinimide (EDC/NHS)—were used. The chemical structure of the derivatives was studied in detail by means of two spectroscopic methods, namely infrared and nuclear magnetic resonance spectroscopy, in order to analyze the preference of the systems towards N- or O-acylation reactions, depending on the synthesis conditions used. The results obtained from advanced 1H-13C HMQC spectra emphasized the challenge of achieving a selective acylation reaction path. -
Gas Phase Synthesis of Interstellar Cumulenes. Mass Spectrometric and Theoretical Studies."
rl ì 6. .B,1l thesis titled: "Gas Phase Synthesis of Interstellar Cumulenes. Mass Spectrometric and Theoretical studies." submitted for the Degree of Doctor of Philosophy (Ph.D') by Stephen J. Blanksby B.Sc.(Hons,) from the Department of ChemistrY The University of Adelaide Cì UCE April 1999 Preface Contents Title page (i) Contents (ii) Abstract (v) Statement of OriginalitY (vi) Acknowledgments (vii) List of Figures (ix) Phase" I Chapter 1. "The Generation and Characterisation of Ions in the Gas 1.I Abstract I 1.II Generating ions 2 t0 l.ru The Mass SPectrometer t2 1.IV Characterisation of Ions 1.V Fragmentation Behaviour 22 Chapter 2 "Theoretical Methods for the Determination of Structure and 26 Energetics" 26 2,7 Abstract 27 2.IT Molecular Orbital Theory JJ 2.TII Density Functional Theory 2.rv Calculation of Molecular Properties 34 2.V Unimolecular Reactions 35 Chapter 3 "Interstellar and Circumstellar Cumulenes. Mass Spectrometric and 38 Related Studies" 3.I Abstract 38 3.II Interstellar Cumulenes 39 3.III Generation of Interstellar Cumulenes by Mass Spectrometry 46 3.IV Summary 59 Preface Chapter 4 "Generation of Two Isomers of C5H from the Corresponding Anions' 61 ATheoreticallyMotivatedMassSpectrometricStudy.'. 6l 4.r Abstract 62 4.rl Introduction 66 4.III Results and Discussion 83 4.IV Conclusions 84 4.V Experimental Section 89 4.VI Appendices 92 Chapter 5 "Gas Phase Syntheses of Three Isomeric CSHZ Radical Anions and Their Elusive Neutrals. A Joint Experimental and Theoretical Study." 92 5.I Abstract 93 5.II Introduction 95 5.ru Results and Discussion t12 5.IV Conclusions 113 5.V Experimental Section ttl 5.VI Appendices t20 Chapter 6 "Gas Phase Syntheses of Three Isomeric ClHz Radical Anions and Their Elusive Neutrals. -
Biophysical Properties of the Iron-Sulfur Clusters In
Properties of Iron-Sulfur Clusters in Heterodisulfide Reductase by Carly Engel A dissertation submitted to the Graduate Faculty of Auburn University in partial fulfillment of the requirements for the Degree of Doctor of Philosophy Auburn, Alabama August 3, 2019 Keywords: heterodisulfide reductase, iron-sulfur clusters, electron paramagnetic resonance, redox studies, rapid freeze quench Approved by Evert Duin, Chair, Professor of Biochemistry Doug Goodwin, Associate Professor of Biochemistry Holly Ellis, William P. Molette Professor of Biochemistry Anne Gorden, Associate Professor of Chemistry Robert Pantazes, Assistant Professor of Chemical Engineering Abstract Global warming is a continuing crisis today. It has caused great damage to our planet and health. One of the leading causes of this issue originates from humans releasing an enormous amount of greenhouse gases into the air, in particular CO2 and CH4. Infrared radiation produced by the sun become trapped by these molecules and, therefore, increases the Earth’s temperature drastically. Ultimately, the source of most of the CH4 is biological. One enzyme known to aid in the production of methane is heterodisulfide reductase (Hdr). Hdr recycles the substrates used by the enzyme that catalyzes the methane formation. In addition, reduced ferredoxin (FdRED) is produced and used to push the first step in methanogenesis. The goal of this research is to understand the role of the cofactors, iron-sulfur clusters, and flavin adenine dinucleotide (FAD) in catalysis, with emphasis on the flavin-based electron bifurcation process and heterodisulfide (HDS) reduction. Redox titrations of methyl-viologen hydrogenase: heterodisulfide reductase (Mvh:Hdr) yielded multiple midpoint potentials for different [4Fe-4S]+ and [2Fe-2S]+ clusters. -
Pahs) in Aqueous Environmental Samples
Sensing and Bio-Sensing Research 7 (2016) 115–120 Contents lists available at ScienceDirect Sensing and Bio-Sensing Research journal homepage: www.elsevier.com/locate/sbsr A highly sensitive monoclonal antibody based biosensor for quantifying 3–5 ring polycyclic aromatic hydrocarbons (PAHs) in aqueous environmental samples Xin Li, Stephen L. Kaattari, Mary A. Vogelbein, George G. Vadas, Michael A. Unger ⁎ Department of Aquatic Health Sciences, Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA 23062, United States article info abstract Article history: Immunoassays based on monoclonal antibodies (mAbs) are highly sensitive for the detection of polycyclic Received 4 December 2015 aromatic hydrocarbons (PAHs) and can be employed to determine concentrations in near real-time. A sensitive Received in revised form 3 February 2016 generic mAb against PAHs, named as 2G8, was developed by a three-step screening procedure. It exhibited nearly Accepted 4 February 2016 uniformly high sensitivity against 3-ring to 5-ring unsubstituted PAHs and their common environmental meth- Available online xxxx ylated PAHs, with IC50 values between 1.68 and 31 μg/L (ppb). 2G8 has been successfully applied on the KinExA – Keywords: Inline Biosensor system for quantifying 3 5 ring PAHs in aqueous environmental samples. PAHs were detected at μ Monoclonal antibody a concentration as low as 0.2 g/L. Furthermore, the analyses only required 10 min for each sample. To evaluate PAH the accuracy of the 2G8-based biosensor, the total PAH concentrations in a series of environmental samples an- Pore water alyzed by biosensor and GC–MS were compared. In most cases, the results yielded a good correlation between Biosensor methods. -
Organometallic Nanoprobe to Enhance Optical Response on the Polycyclic Aromatic Hydrocarbon Benzo[A]Pyrene Immunoassay Using SERS Technology
1 Environmental Science And Pollution Research Achimer December 2017, Volume 24 Issue 35 Pages 27070-27076 http://dx.doi.org/10.1007/s11356-014-3384-8 http://archimer.ifremer.fr http://archimer.ifremer.fr/doc/00417/52844/ © Springer-Verlag Berlin Heidelberg 2014 Organometallic nanoprobe to enhance optical response on the polycyclic aromatic hydrocarbon benzo[a]pyrene immunoassay using SERS technology Dribek Mohamed 1, 3, Rinnert Emmanuel 1, *, Colas Florent 1, Crassous Marie-Pierre 1, Thioune Nene 2, David Carmen 2, 4, De La Chapelle Marc 2, Compere Chantal 1 1 IFREMER, Lab Detect Capteurs & Mesures, CS10070, F-29280 Plouzane, France. 2 Univ Paris 13, UFR SMBH, Lab CSPBAT FRE 3043, 74 Rue Marcel Cachin, F-93017 Bobigny, France. 3 Univ Francois Rabelais Tours, UFR Sci Pharmaceut, EA Nanomedicaments & Nanosondes 6295, 31 Ave Monge, F-37200 Tours, France. 4 Horiba Sci, 231 Rue Lille, F-59650 Villeneuve Dascq, France. * Corresponding author : Emmanuel Rinnert, email address : [email protected] Abstract : We demonstrated the use of a new organometallic nanoprobe for competitive surface-enhanced Raman scattering (SERS) immunoassay devoted to the detection of polycyclic aromatic hydrocarbons (PAH) such as benzo[a]pyrene (BaP) in seawater. The nanoprobes are gold nanoparticles (GNPs) labeled by a Raman reporter, the 5,5'-dithiobis(succinimidyl-2-nitrobenzoate) (DSNB) and functionalized with monoclonal antibodies anti-BaP. The antibodies are bound with a high specificity to the analyte while the GNPs enhanced the Raman scattering of the DSNB. This type of immunoassay involved the grafting of BaP onto a sensing surface. Thus, NH2-terminated self-assembled monolayer is formed on the surface of gold substrate using cysteamine. -
Fully Inkjet-Printed Biosensors Fabricated with a Highly Stable Ink Based on Carbon Nanotubes and Enzyme-Functionalized Nanoparticles
nanomaterials Article Fully Inkjet-Printed Biosensors Fabricated with a Highly Stable Ink Based on Carbon Nanotubes and Enzyme-Functionalized Nanoparticles Mijal Mass 1 , Lionel S. Veiga 1, Octavio Garate 1, Gloria Longinotti 1, Ana Moya 2,†, Eloi Ramón 2 , Rosa Villa 2,3, Gabriel Ybarra 1,* and Gemma Gabriel 2,3,* 1 INTI-Micro y Nanotecnologías, Instituto Nacional de Tecnología Industrial (INTI), San Martín, Buenos Aires B1650WAB, Argentina; [email protected] (M.M.); [email protected] (L.S.V.); [email protected] (O.G.); [email protected] (G.L.) 2 Institut de Microelectrònica de Barcelona, IMB-CNM (CSIC), Campus Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain; [email protected] (A.M.); [email protected] (E.R.); [email protected] (R.V.) 3 CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), 28029 Madrid, Spain * Correspondence: [email protected] (G.Y.); [email protected] (G.G.) † Present Addresses: Eurecat, Centre Tecnològic de Catalunya, Functional Printing & Embedded Devices Unit, 08302 Mataró, Spain. Abstract: Enzyme inks can be inkjet printed to fabricate enzymatic biosensors. However, inks Citation: Mass, M.; Veiga, L.S.; containing enzymes present a low shelf life because enzymes in suspension rapidly lose their Garate, O.; Longinotti, G.; Moya, A.; catalytic activity. Other major problems of printing these inks are the non-specific adsorption of Ramón, E.; Villa, R.; Ybarra, G.; enzymes onto the chamber walls and stability loss during printing as a result of thermal and/or Gabriel, G. Fully Inkjet-Printed mechanical stress. -
Title of Thesis Or Dissertation, Worded
DEVELOPMENT OF CHEMICAL TOOLS FOR STUDYING REACTIVE SULFUR SPECIES by MATTHEW MICHAEL CERDA A DISSERTATION Presented to the Department of Chemistry and Biochemistry and the Graduate School of the University of Oregon in partial fulfillment of the requirements for the degree of Doctor of Philosophy June 2020 DISSERTATION APPROVAL PAGE Student: Matthew Michael Cerda Title: Development of Chemical Tools for Studying Reactive Sulfur Species This dissertation has been accepted and approved in partial fulfillment of the requirements for the Doctor of Philosophy degree in the Department of Chemistry and Biochemistry by: Michael M. Haley Chairperson Michael D. Pluth Advisor Darren W. Johnson Core Member Raghuveer Parthasarathy Institutional Representative and Kate Mondloch Interim Vice Provost and Dean of the Graduate School Original approval signatures are on file with the University of Oregon Graduate School. Degree awarded June 2020 ii © 2020 Matthew Michael Cerda This work is licensed under a Creative Commons Attribution-NonCommerical-NoDerivs (United States) License. iii DISSERTATION ABSTRACT Matthew Michael Cerda Doctor of Philosophy Department of Chemistry and Biochemistry June 2020 Title: Development of Chemical Tools for Studying Reactive Sulfur Species Hydrogen sulfide (H2S) has recently emerged as an important biological signaling molecule involved in a number of key physiological processes. These observations have generated interest in harnessing H2S as a potential therapeutic agent to treat disease states and chronic conditions associated with H2S-based signaling. A mechanistic analysis of these physiological processes reveals the prevalence of H2S and other reactive sulfur species including sulfane sulfur and persulfides. To better understand the biological properties of these reactive sulfur species, chemical tools which provide methods of generating these fleeting species under controlled reaction conditions are needed.