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51.
Simen Gjelseth Antonsen Arne Joakim C. Bunkan Tomas Mikoviny Yngve Stenstrøm Armin Wisthaler 《Molecular physics》2020,118(15)
The kinetics of the O3, OH and NO3 radical reactions with diazomethane were studied in smog chamber experiments employing long-path FTIR and PTR-ToF-MS detection. The rate coefficients were determined to be k CH2NN+O3?=?(3.2?±?0.4)?×?10?17 and k CH2NN+OH?=?(1.68?±?0.12)?×?10?10 cm3 molecule?1 s?1 at 295?±?3?K and 1013?±?30 hPa, whereas the CH2NN?+?NO3 reaction was too fast to be determined in the static smog chamber experiments. Formaldehyde was the sole product observed in all the reactions. The experimental results are supported by CCSD(T*)-F12a/aug-cc-pVTZ//M062X/aug-cc-pVTZ calculations showing the reactions to proceed exclusively via addition to the carbon atom. The atmospheric fate of diazomethane is discussed. 相似文献
52.
Jigneshkumar P. Patel Zou Guo Xiang Shaw Ling Hsu Andrew B. Schoch Sena Ada Carleen Dean Matsumoto 《Journal of Polymer Science.Polymer Physics》2015,53(21):1519-1526
A uniform dispersion of reactants is necessary to achieve a complete reaction involving multicomponents. In this study, we have examined the role of plasticizer in the reaction of two seemingly unlikely reactants: a highly crystalline hexamethylenetetramine (HMTA) and a strongly hydrogen bonded phenol formaldehyde resin. By combining information from NMR, infrared spectroscopy and differential scanning calorimetry, we were able to determine the role of specific intermolecular interactions necessary for the plasticizer to dissolve the highly crystalline HMTA and to plasticize the phenol formaldehyde resin in this crosslinking reaction. The presence of the plasticizer increased the segmental mobility, disrupted the hydrogen bonded matrix, and freed the hydroxyl units, which further increased the solubility of the HMTA. Both the endothermic and exothermic transitions are accounted for in the calorimetric data obtained. For the first time, it is possible to obtain the effective molar ratio of each component needed to complete the crosslinking reaction efficiently. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1519–1526 相似文献
53.
Prof. Dr. Frank Glorius 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(22):8047-8051
A general and efficient methodology for the direct transition metal free trifluoromethylthiolation of a broad range of biologically relevant N‐heteroarenes is reported employing abundant sodium chloride as the catalyst. This method is operationally simple, exhibits high functional group tolerance, and does not require protecting groups. 相似文献
54.
Degradation of pyrene in soil in a net-to-net pulsed discharge plasma (PDP) system was reviewed. Effect of main chemical parameters, including air flow rate, pyrene concentration, initial pH and soil moisture content on pyrene degradation was examined. The obtained results show that 87.9% of pyrene could be removed under the condition of 60 min reaction; increasing of air flow rate within 1 L min−1 was favorable for degradation; pyrene removal was decreased with the increase of initial pyrene concentration; oxidation of pyrene was more evident in acidic soil; enhancement of soil moisture content has no benefit on pyrene degradation. 相似文献
55.
Riboflavin was covalently linked to mesoporous SBA-15 silica surface via grafting technique. Then fluorescence properties of the system obtained were analyzed in the presence of several metal and organic cations. Both quenching and strengthening of fluorescence as well as significant changes in the maximum fluorescence wavelength were observed. The results were compared with absorption and fluorescence data obtained for riboflavin water solutions. 相似文献
56.
Crosslinked poly(ethylene oxide) containing siloxanes fabricated through thiol‐ene photochemistry
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Victor A. Kusuma Elliot A. Roth William P. Clafshenkel Steven S. Klara Xu Zhou Surendar R. Venna Erik Albenze David R. Luebke Meagan S. Mauter Richard R. Koepsel Alan J. Russell David Hopkinson Hunaid B. Nulwala 《Journal of polymer science. Part A, Polymer chemistry》2015,53(13):1548-1557
Homogenous amphiphilic crosslinked polymer films comprising of poly(ethylene oxide) and polysiloxane were synthesized utilizing thiol‐ene “ click ” photochemistry. A systematic variation in polymer composition was Carried out to obtain high quality films with varied amount of siloxane and poly(ethylene oxide). These films showed improved gas separation performance with high gas permeabilities with good CO2/N2 selectivity. Furthermore, the resulting films were also tested for its biocompatibility, as a carrier media which allow human adult mesenchymal stem cells to retain their capacity for osteoblastic differentiation after transplantation. The obtained crosslinked films were characterized using differential scanning calorimetry, dynamic mechanical analysis, thermogravimetric analysis, FTIR, Raman‐IR , and small angle X‐ray scattering. The synthesis ease and commercial availability of the starting materials suggests that these new crosslinked polymer networks could find applications in wide range of applications. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1548–1557 相似文献
57.
Natalia L. Calvo Sebastian O. SimonettiRubén M. Maggio Teodoro S. Kaufman 《Analytica chimica acta》2015
Exposure of cimetidine (CIM) to dry heat (160–180 °C) afforded, upon cooling, a glassy solid containing new and hitherto unknown products. The kinetics of this process was studied by a second order chemometrics-assisted multi-spectroscopic approach. Proton and carbon-13 nuclear magnetic resonance (NMR), as well as ultraviolet and infrared spectroscopic data were jointly used, whereas multivariate curve resolution with alternating least squares (MCR-ALS) was employed as the chemometrics method to extract process information. It was established that drug degradation follows a first order kinetics. 相似文献
58.
The discharge of diverse pollutants has led to a complex water environment and posed a huge health threat to humans and animals. Self-propelled micromotors have recently attracted considerable attention for efficient water remediation due to their strong localized mass transfer effect. However, a single functionalized component is difficult to tackle with multiple contaminants and requires to combine different decontamination effects together. Here, we introduced a multifunctional micromotor to implement the adsorption and degradation roles simultaneously by integrating the poly(aspartic acid) (PASP) adsorbent with a MnO2-based catalyst. The as-prepared micromotors are well propelled in contaminated waters by MnO2 catalyzing hydrogen peroxide. In addition, the catalytic ramsdellite MnO2(R-MnO2) inner layer is decorated with Fe2O3 nanoparticles to improve their catalytic performance, contributing to an excellent degradation ability with 90% tetracycline (TC) removal in 50 minutes by enhanced Fenton-like reactions. Combining the attractive adsorption capability of poly (aspartic acid) (PASP), the composite micromotors offer an efficient removal of heavy metal ions in short time. Moreover, the designed micromotors are able to simultaneously remove antibiotic and heavy metals in mixed contaminants circumstance just in single treatment. This multifunctional micromotor with distinctive decontamination ability exhibits a promising prospective in treating multiple pollutants in the future. 相似文献
59.
Naphthalimide‐phthalimide derivative based photoinitiating systems for polymerization reactions under blue lights
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Pu Xiao Frédéric Dumur Jing Zhang Bernadette Graff Didier Gigmes Jean Pierre Fouassier Jacques Lalevée 《Journal of polymer science. Part A, Polymer chemistry》2015,53(5):665-674
Naphthalimide‐phthalimide derivatives (NDPDs) have been synthesized and combined with an iodonium salt, N‐vinylcarbazole, amine or 2,4,6‐tris(trichloromethyl)‐1,3,5‐triazine to produce reactive species (i.e., radicals and cations). These generated reactive species are capable of initiating the cationic polymerization of epoxides and/or the radical polymerization of acrylates upon exposure to very soft polychromatic visible lights or blue lights. Compared with the well‐known camphorquinone based systems used as references, the novel NDPD based combinations employed here demonstrate clearly higher efficiencies for the cationic polymerization of epoxides under air as well as the radical polymerization of acrylates. Remarkably, one of the NDPDs (i.e., NDPD2) based systems is characterized by an outstanding reactivity. The structure/reactivity/efficiency relationships of the investigated NDPDs were studied by fluorescence, cyclic voltammetry, laser flash photolysis, electron spin resonance spin trapping, and steady state photolysis techniques. The key parameters for their reactivity are provided. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 665–674 相似文献
60.
《Physics letters. A》2019,383(17):2090-2092
In this paper, we have used Monte Carlo (MC) method to simulate and study the temperature and doping effects on the electric conductivity of fullerene (C60). The results show that the band gap has reduced by the doping and the charge carrier transport is facilitated from valence band to conduction band by the temperature where is touched a 300 K. In this case, the conductivity reached a value of . The electric conductivity of C60 can increase by the triphenylmethane dye crystal violet (CV) alkali metal to reach at 303 K. Our results of MC simulation have a good agreement with those extracted from literature [10], [33]. 相似文献