The Experts below are selected from a list of 14181 Experts worldwide ranked by ideXlab platform
Tao Wang - One of the best experts on this subject based on the ideXlab platform.
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highly recyclable polymer supported ionic liquids as efficient heterogeneous catalysts for batch and flow conversion of co2 to cyclic carbonates
RSC Advances, 2017Co-Authors: Tao Wang, Wenlong Wang, Yuan Lyu, Xingkun Chen, Yan Zhang, Xiangen Song, Yunjie DingAbstract:A series of cross-linked polymer supported ionic liquids based on quaternary ammonium salts have been prepared using a facile method of radical polymerization. Styrene-functionalized quaternary ammonium chloride salts, which are derived from imidazole, trimethylamine, Triethylamine and triethanolamine, were copolymerized with divinyl benzene (DVB) under solvothermal conditions. These polymer supported ionic liquids displayed high efficiency in catalytic conversion of CO2 to cyclic carbonates. Notably, to the best of our knowledge, it was the first time that the polymeric ionic liquid catalyst was applied in a continuous flow fixed-bed reactor. During the study period of 130 hours, the polymer supported ionic liquids exhibited high stability.
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correction highly recyclable polymer supported ionic liquids as efficient heterogeneous catalysts for batch and flow conversion of co2 to cyclic carbonates
RSC Advances, 2017Co-Authors: Tao Wang, Wenlong Wang, Yuan Lyu, Xingkun Chen, Yan Zhang, Xiangen Song, Yunjie DingAbstract:A series of cross-linked polymer supported ionic liquids based on quaternary ammonium salts have been prepared using a facile method of radical polymerization. Styrene-functionalized quaternary ammonium chloride salts, which are derived from imidazole, trimethylamine, Triethylamine and triethanolamine, were copolymerized with divinyl benzene (DVB) under solvothermal conditions. These polymer supported ionic liquids displayed high efficiency in catalytic conversion of CO2 to cyclic carbonates. Notably, to the best of our knowledge, it was the first time that the polymeric ionic liquid catalyst was applied in a continuous flow fixed-bed reactor. During the study period of 130 hours, the polymer supported ionic liquids exhibited high stability.
J. H. Seinfeld - One of the best experts on this subject based on the ideXlab platform.
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*This chapter is reproduced by permission from “Secondary aerosol formation from
2014Co-Authors: Aliphatic Amines, J. H. SeinfeldAbstract:Although aliphatic amines have been detected in both urban and rural atmospheric aerosols, little is known about the chemistry leading to particle formation or the potential aerosol yields from reactions of gas-phase amines. We present here the first systematic study of aerosol formation from the atmospheric reactions of amines. Based on laboratory chamber experiments and theoretical calculations, we evaluate aerosol formation from reaction of OH, ozone, and nitric acid with trimethylamine, methylamine, Triethylamine, diethylamine, ethylamine, and ethanolamine. Entropies of formation for alkylammonium nitrate salts are estimated by molecular dynamics calculations enabling us to estimate equilibrium constants for the reactions of amines with nitric acid. Though subject to significant uncertainty, the calculated dissociation equilibrium constant for diethylammonium nitrate is found to be sufficiently small to allow for its atmospheric formation, even in the presence of ammonia which competes for available nitric acid. Experimental chamber studies indicate that the dissociation equilibrium constant for triethylammonium nitrate is of the same order of magnitude as that for ammonium nitrate. All amines studied form aerosol when photooxidized in the presence of NOx with the majority of the aerosol mass present at the peak of aerosol growth consisting of aminium (R3NH +) nitrate salts, which repartition back to the gas phase as the parent amine is consumed. Only the two tertiary amines studied, trimethylamine and Triethylamine, are found to form significant non-salt organic aerosol when oxidized by OH or ozone; calculated organic mass yields for the experiments conducted are similar for ozonolysis (15 % and 5 % respectively) and photooxidation (23 % and 8% respectively). The non-salt organic aerosol formed appears to be more stable than the92 nitrate salts and does not quickly repartition back to the gas phase
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Secondary aerosol formation from atmospheric reactions of aliphatic amines
Atmospheric Chemistry and Physics, 2007Co-Authors: S. M. Murphy, A. Sorooshian, J. H. Kroll, P. Chhabra, C. Tong, J. D. Surratt, E. Knipping, R. C. Flagan, J. H. SeinfeldAbstract:Although aliphatic amines have been detected in both urban and rural atmospheric aerosols, little is known about the chemistry leading to particle formation or the potential aerosol yields from reactions of gas-phase amines. We present here the first systematic study of aerosol formation from the atmospheric reactions of amines. Based on laboratory chamber experiments and theoretical calculations, we evaluate aerosol formation from reaction of OH, ozone, and nitric acid with trimethylamine, methylamine, Triethylamine, diethylamine, ethylamine, and ethanolamine. Entropies of formation for alkylammonium nitrate salts are estimated by molecular dynamics calculations enabling us to estimate equilibrium constants for the reactions of amines with nitric acid. Though subject to significant uncertainty, the calculated dissociation equilibrium constant for diethylammonium nitrate is found to be sufficiently small to allow for its atmospheric formation, even in the presence of ammonia which competes for available nitric acid. Experimental chamber studies indicate that the dissociation equilibrium constant for triethylammonium nitrate is of the same order of magnitude as that for ammonium nitrate. All amines studied form aerosol when photooxidized in the presence of NOx with the majority of the aerosol mass present at the peak of aerosol growth consisting of aminium (R3NH+) nitrate salts, which repartition back to the gas phase as the parent amine is consumed. Only the two tertiary amines studied, trimethylamine and Triethylamine, are found to form significant non-salt organic aerosol when oxidized by OH or ozone; calculated organic mass yields for the experiments conducted are similar for ozonolysis (15% and 5% respectively) and photooxidation (23% and 8% respectively). The non-salt organic aerosol formed appears to be more stable than the nitrate salts and does not quickly repartition back to the gas phase.
Masakazu Anpo - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of nitrogen doped tio2 nanophotocatalyst with high visible light activity
Journal of Physical Chemistry C, 2007Co-Authors: Ye Cong, Jinlong Zhang, And Feng Chen, Masakazu AnpoAbstract:Nitrogen-doped TiO2 nanocatalysts with a homogeneous anatase structure were successfully synthesized through a microemulsion−hydrothermal method by using some organic compounds such as Triethylamine, urea, thiourea, and hydrazine hydrate. Analysis by Raman and X-ray photoemission spectroscopy indicated that nitrogen was doped effectively and most nitrogen dopants might be present in the chemical environment of Ti−O−N and O−Ti−N. A shift of the absorption edge to a lower energy and a stronger absorption in the visible light region were observed. The results of photodegradation or the organic pollutant rhodamine B in the visible light irradiation (λ > 420 nm) suggested that the TiO2 photocatalysts after nitrogen doping were greatly improved compared with the undoped TiO2 photocatalysts and Degussa P-25; especially the nitrogen-doped TiO2 using triathylamine as the nitrogen source showed the highest photocatalytic activity, which also showed a higher efficiency for photodecomposition of 2,4-dichlorophenol. T...
Yan Zhu - One of the best experts on this subject based on the ideXlab platform.
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high capacity anion exchangers based on poly glycidylmethacrylate divinylbenzene microspheres for ion chromatography
Talanta, 2016Co-Authors: Junwei Liu, Yong Wang, Heli Cheng, Nani Wang, Peimin Zhang, Yan ZhuAbstract:Poly (glycidylmethacrylate-divinylbenzene) microspheres were prepared by the two-staged swelling and polymerization method and applied to prepare anion exchange stationary phases. Methylamine, dimethylamine, trimethylamine, diethylamine and Triethylamine were selected to prepare the quaternary ammonium groups of anion exchangers, respectively. The diameters and surface characteristics of microspheres were measured by scanning electron microscope and nitrogen adsorption-desorption measurements. The anion exchangers were characterized by Fourier transform infrared spectrum, elemental analysis and breakthrough curve methods. The chromatographic performances of anion exchangers were illustrated by separating conventional anions, organic weak acids and carbohydrates. The results indicated that the anion exchange capacities were controllable by changing either the content of glycidylmethacrylate in microspheres or the number of bonded quaternary ammonium layer. Meanwhile, the substituents of quaternary ammonium groups greatly influenced the separation properties of anion exchangers. Finally, the three-layer methylamine-quaternized anion exchanger was successfully applied for the determination of fluoride in tea sample. The content of fluoride was detected to be 0.13mgg(-1) without the interference of acetate and formate.
Bogdan Zygmunt - One of the best experts on this subject based on the ideXlab platform.
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determination of volatile aliphatic amines in air by solid phase microextraction coupled with gas chromatography with flame ionization detection
Journal of Chromatography A, 2003Co-Authors: Jacek Namieśnik, Anna Jastrzebska, Bogdan ZygmuntAbstract:Practical aspects of the application of solid-phase microextraction (SPME) to the determination of volatile aliphatic amines in air are described. Analytes included methylamine (MA), ethylamine (EA), dimethylamine (DMA), diethylamine (DEA), trimethylamine (TMA) and Triethylamine (TEA). New SPME stationary phases were examined. The effects of relative humidity and temperature on analytes uptake were taken into account in analysis. Gas chromatography (GC) with flame ionization detector (FID) was used for the final analysis.
