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41.
42.
In this work, poly(fluorocyclopentenyl)siloxane (FPCS) was obtained via a single electron transfer addition reaction of poly(cyclopentadienyl)siloxane (PCS) and perfluoroalkyl iodides, and reduction reaction of the intermediates. PCS was prepared by substitution and hydrolysis reactions using methyltrichlorosilane and sodium cyclopentadienide (NaCp) as raw materials. Fourier transform infrared (FTIR), 1H NMR, and 19F NMR indicated the structures of the target polymers. The XPS results showed that the thin films prepared by dip-coating were fluorine enriched at the surface. Atomic force microscopy (AFM) image showed that on the rough surface of films, there were many pinnacles which were generated through the migration of side chain fluoroalkyl groups. The relative static contact angles of water and n-hexadecane on FPCS and PCS indicated that sodium dithionite initiated the reaction of perfluoroalkyl iodides and PCS so that FPCS was successfully synthesized. The measured surface energy of PCS was 2.57 × 10?2 N/m; while FPCS was 2.14 × 10?2 N/m, which represented better liquid repellent property compared to PCS. 相似文献
43.
44.
Shao-Liang Zhang Zhao-Feng Xue Ya-Ru Gao Shuai Mao Yong-Qiang Wang 《Tetrahedron letters》2012,53(19):2436-2439
An efficient triple condensation reaction of aryl methyl ketones catalyzed by ethylenediamine and trifluoroacetic acid was reported. A broad scope of 1,3,5-triarylbenzenes was obtained in good to excellent yields. The reaction provides a novel and practical approach to access organic materials of polycyclic aromatic hydrocarbons under mild conditions. 相似文献
45.
Song-Bai Yu Hong-Jun Zang Xiao-Li Yang Ming-Chuan Zhang Rui-Rui Xie Pei-Fei Yu 《中国化学快报》2017,28(7):1479-1484
Several types of ILs and solid acids were used as catalysts in one-pot conversion of sucrose to 5-hydroxymethylfurfural (abbreviated as 5-HMF) in a dimethyl sulfoxide (DMSO)/water mixed solvent under hydrothermal conditions. A remarkable 5-HMF yield of 91.8% was achieved catalyzed by the cesium salt of dodecatungstophosphoric acid (Cs2.3H0.7PW12O40) within 3 h at 180 ℃. The ionic liquid N-methylimidazolium hydrogen sulfate ([Hmim][HSO4]) gave the 5-HMF in 82.0% yield from sucrose. To the best of our knowledge, it was almost the highest yield of HMF from sucrose by now. Various reaction parameters including reaction temperature and time and catalyst dosage were optimized. A possible mechanism for this catalytic process was proposed. Furthermore, fructose and glucose were also investigated, good yields of 5-HMF was obtained respectively. This increases the possibility of large-scale production of 5-HMF from carbohydrates. 相似文献
46.
Qiang Wei Fulong Zhang Feilong Li Haifeng Li Pan Zang Changsheng Zhao 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(2):135-141
In this study, stimuli-responsive nanoparticles were prepared by solution polymerization. Two synthesis routes are proposed to synthesize the particles, the monomer route and the polymer/monomer route. For the monomer route, pH and thermal sensitive nanoparticles were synthesized from acrylic acid and N-isopropylacrylamide. For the polymer/monomer route, the pH sensitive nanoparticles were synthesized from chitosan and acrylic acid. The effect of reaction time, initiator concentration and agitation rate on the particle size and the size distribution were investigated. The stimuli-responsive nanoparticles could be directly blended with other polymers to prepare stimuli-responsive functional membranes. 相似文献
47.
Guoliang Wu Guangpeng Liu Yangling Zang Yanbing Lu Yuanqin Xiong Weijian Xu 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(7):647-654
A long-chain surfactant, enzoylbenzyl-N,N-dimethyl-N-octadecylammonium bromide (BDOB) with a benzophenone group, was synthesized to modify the montmorillonites (MMT) for the preparation of nanocomposites via photo-induced polymerization. The BDOB-modified MMT was characterized by the fourier transform infrared spectrometer (FTIR), thermal gravimetric analyzer (TGA) and X-ray diffraction (XRD), and the results of XRD indicated that the intercalated structures of BDOB-modified MMT was obtained. The conversion of the bisphenol A epoxy diacrylate (EA) was quantified by the FTIR, and the results indicated that conversion increased with an increase in the amount of BDOB-modified MMT. The morphologies of the UV-cured EA/MMT nanocomposites prepared from this organically modified MMT were studied by means of XRD and TEM, and the results showed that all the samples contained an intercalated structure with partial exfoliated structure. The results of TGA and mechanical properties also indicated that the thermal and mechanical properties of UV-cured nanocomposites were significantly enhanced due to the presence of the long chain surfactant organically modified MMT. 相似文献
48.
Iulius I. E. Markovits Dr. Wilhelm A. Eger Dr. Shuang Yue Dr. Mirza Cokoja Christian J. Münchmeyer Bo Zhang Dr. Ming‐Dong Zhou Dr. Alexander Genest Prof. Dr. János Mink Prof. Dr. Shu‐Liang Zang Prof. Dr. Notker Rösch Prof. Dr. Fritz E. Kühn 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(19):5972-5979
Imidazolium‐based ionic liquids that contain perrhenate anions are very efficient reaction media for the epoxidation of olefins with H2O2 as an oxidant, thus affording cyclooctene in almost quantitative yields. The mechanism of this reaction does not follow the usual pathway through peroxo complexes, as is the case with long‐known molecular transition‐metal catalysts. By using in situ Raman, FTIR, and NMR spectroscopy and DFT calculations, we have shown that the formation of hydrogen bonds between the oxidant and perrhenate activates the oxidant, thereby leading to the transfer of an oxygen atom onto the olefin demonstrating the special features of an ionic liquid as a reaction environment. The influence of the imidazolium cation and the oxidant (aqueous H2O2, urea hydrogen peroxide, and tert‐butyl hydrogen peroxide) on the efficiency of the epoxidation of cis‐cyclooctene were examined. Other olefinic substrates were also used in this study and they exhibited good yields of the corresponding epoxides. This report shows the potential of using simple complexes or salts for the activation of hydrogen peroxide, owing to the interactions between the solvent medium and the active complex. 相似文献
49.
Vacuum Ultraviolet Free-Electron Laser Photoionization Mass Spectrometry of Alpha-pinene Ozonolysis
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Xiangyu Zang Zhaoyan Zhang Chong Wang Tiantong Wang Huijun Zheng Hua Xie Jiayue Yang Dongxu Dai Guorong Wu Weiqing Zhang Gang Li Xueming Yang Ling Jiang 《化学物理学报(中文版)》2022,35(2):281-288
50.
Jilong Li Yanhui Wang Rushuo Li Bowen Lu Yungang Yuan Hongwei Gao Shiwei Song Shuyu Zhou Jianbing Zang 《Electroanalysis》2021,33(10):2252-2259
A self-modified film electrode consisting of homogeneous snowflake-shaped nanoparticles on the amorphous carbon substrate (HNAC) was prepared by low temperature carbonization of phenolic resin. Such a unique structure was beneficial to enhance the electroanalysis signal responds. Simultaneous detection of DA and UA was performed on the HNAC using differential pulse voltammetry (DPV) at pH 8 phosphate buffer. The well-defined oxidation peak potential separation reached 260 mV between DA and UA. Meanwhile, the detection limit of HNAC were 0.401 μM (DA) and 2.800 μM (UA). 相似文献