A new type of vanadium-containing ionic liquids (ILs) was synthesized by cation exchange from barium salts of oxidovanadium(IV) complexes stabilized by edta and its congeners (dcta, oedta, and heedta) serving as pentadentate ligands. All starting barium salts and several magnesium and cesium salts, serving as models for the cation exchange, were structurally characterized by single-crystal XRD analysis. The synthesized ILs consisting of organic cations (BuN, Bmim, and BuP) and complex anions ([VO(edta)], [VO(dcta)], [VO(oedta)], and [VO(heedta)]) were characterized by analytical and spectroscopic methods including EPR spectroscopy and cyclic voltammetry. Then, ILs were tested as catalysts for the ring-opening copolymerization of epoxy resin with cyclic anhydride showing significant catalytic activity, which led to production of highly cross-linked glassy thermosets. A detailed isothermal DSC kinetic study was performed for the most promising IL showing that the progress of cross-linking can be successfully fitted by the Kamal-Sourour model. Based on the DSC and NIR results, the initiation mechanism of the cross-linking in the presence of vanadium-containing IL was suggested. IL had ability to activate a rapid hydrolysis of anhydride cycle and the formed carboxyl groups initiated a polyesterification. In parallel, the role of imidazolium cation of IL for the initiation of chain-growth anionic copolymerization is also discussed.
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http://dx.doi.org/10.1021/acs.inorgchem.4c01663 | DOI Listing |
Inorg Chem
September 2024
Institute of Chemistry and Technology of Macromolecular Materials, Faculty of Chemical Technology, University of Pardubice, Studentská 573, Pardubice 532 10, Czech Republic.
A new type of vanadium-containing ionic liquids (ILs) was synthesized by cation exchange from barium salts of oxidovanadium(IV) complexes stabilized by edta and its congeners (dcta, oedta, and heedta) serving as pentadentate ligands. All starting barium salts and several magnesium and cesium salts, serving as models for the cation exchange, were structurally characterized by single-crystal XRD analysis. The synthesized ILs consisting of organic cations (BuN, Bmim, and BuP) and complex anions ([VO(edta)], [VO(dcta)], [VO(oedta)], and [VO(heedta)]) were characterized by analytical and spectroscopic methods including EPR spectroscopy and cyclic voltammetry.
View Article and Find Full Text PDFNature
August 2016
Center for Nanoscale Materials, 9700 South Cass Avenue, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Moving mechanical interfaces are commonly lubricated and separated by a combination of fluid films and solid 'tribofilms', which together ensure easy slippage and long wear life. The efficacy of the fluid film is governed by the viscosity of the base oil in the lubricant; the efficacy of the solid tribofilm, which is produced as a result of sliding contact between moving parts, relies upon the effectiveness of the lubricant's anti-wear additive (typically zinc dialkyldithiophosphate). Minimizing friction and wear continues to be a challenge, and recent efforts have focused on enhancing the anti-friction and anti-wear properties of lubricants by incorporating inorganic nanoparticles and ionic liquids.
View Article and Find Full Text PDFJ Phys Chem A
April 2010
Department of Materials Science and Engineering, Fujian Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen 361005, China.
To gain more insight into the interactions between vanadium and l-proline, the dynamic transformation of the reaction system of vanadium with l-proline and the coordination structures of the vanadium-containing products in 0.15 mol/L NaCl ionic medium mimicking physiological conditions were explored by multinuclear ((1)H, (13)C, (51)V) NMR, ESR, ESI-MS as well as density functional theory (DFT) calculations. Spectroscopic evidence and computational results showed that a monoperoxovanadium species [VO(O(2))(l-proline)(2)](-) was a major product, where l-proline coordinated to vanadium via nitrogen and oxygen atoms in a bidentate manner to form a distorted pentagonal bipyramidal structure.
View Article and Find Full Text PDFChem Asian J
November 2006
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Crystalline vanadium pentoxide with hierarchical mesopores was synthesized by using a CTAB/BMIC cotemplate (CTAB = cetyltrimethylammonium bromide, BMIC = 1-butyl-3-methylimidazolium chloride). The material was fully characterized by SEM, TEM, N2 adsorption-desorption, XRD, XPS, and CV methods. By elaborate adjustment of the template proportions, the distribution and size of the hierarchical pores were tuned successfully.
View Article and Find Full Text PDFLangmuir
August 2004
Department of Chemical Engineering, State University of New York at Buffalo, Amherst, New York 14260, USA.
Mesostructured V-Mg oxides were synthesized using the surfactant cetyltrimethylammonium bromide (CTAB) as template, V2O5, V(acac)3 (vanadium acetylacetonate), or NH4VO3 as vanadium source, and Mg(NO3)2, MgCl2, MgSO4, (MgCO3)4.Mg(OH)2, Mg(CH3CO2)2, or Mg(C2H5O)2 as magnesium source. The factors that influence the formation of mesostructured V-Mg oxides, such as the pH, the natures of magnesium and vanadium sources, and the ionic strength, were identified.
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