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71.
Vanessa A. Béland Zhiqiang Wang Prof. Tsun‐Kong Sham Prof. Paul J. Ragogna 《Angewandte Chemie (International ed. in English)》2018,57(40):13252-13256
The synthesis of phosphane‐ene photopolymer networks, where the networks are composed of crosslinked tertiary alkyl phosphines are reported. Taking advantage of the rich coordination chemistry of alkyl phosphines, stibino‐phosphonium and stibino‐bis(phosphonium) functionalized polymer networks could be generated. Small‐molecule stibino‐phosphonium and stibino‐bis(phosphonium) compounds have been well characterized previously and were used as models for spectroscopic comparison to the macromolecular analogues by NMR and XANES spectroscopy. This work reveals that the physical and electronic properties of the materials can be tuned depending on the type of coordination environment. These materials can be used as ceramic precursors, where the Sb‐functionalized polymers influence the composition of the resulting ceramic. 相似文献
72.
Qing-Long Meng Hengchang Liu Zhiwei Huang Shuang Kong Peng Jiang Xinhe Bao 《中国化学快报》2018,29(5):711-715
The thermal conductivity of graphene oxides can be tailored by tuning oxidation degree due to the introduction of atomic- and nano-scale phonon scattering centers. 相似文献
73.
Alloying n‐Butylamine into CsPbBr3 To Give a Two‐Dimensional Bilayered Perovskite Ferroelectric Material 下载免费PDF全文
Zhenyue Wu Chengmin Ji Dr. Lina Li Dr. Jintao Kong Prof. Zhihua Sun Prof. Sangen Zhao Sasa Wang Prof. Maochun Hong Prof. Junhua Luo 《Angewandte Chemie (International ed. in English)》2018,57(27):8140-8143
Cesium‐lead halide perovskites (e.g. CsPbBr3) have gained attention because of their rich physical properties, but their bulk ferroelectricity remains unexplored. Herein, by alloying flexible organic cations into the cubic CsPbBr3, we design the first cesium‐based two‐dimensional (2D) perovskite ferroelectric material with both inorganic alkali metal and organic cations, (C4H9NH3)2CsPb2Br7 ( 1 ). Strikingly, 1 shows a high Curie temperature (Tc=412 K) above that of BaTiO3 (ca. 393 K) and notable spontaneous polarization (ca. 4.2 μC cm?2), triggered by not only the ordering of organic cations but also atomic displacement of inorganic Cs+ ions. To our knowledge, such a 2D bilayered Cs+‐based metal–halide perovskite ferroelectric material with inorganic and organic cations is unprecedented. 1 also shows photoelectric semiconducting behavior with large “on/off” ratios of photoconductivity (>103). 相似文献
74.
Effect of formulation of silica‐based solution on corrosion resistance of silicate coating on hot‐dip galvanized steel 下载免费PDF全文
Shuang‐hong Zhang Gang Kong Zi‐wen Sun Chun‐shan Che Jin‐tang Lu 《Surface and interface analysis : SIA》2016,48(3):132-138
Several silica‐based solutions with 50 g/l of SiO2 were prepared from sodium silicate solutions and silica sol; the silicate conversion coatings were obtained by immersing hot‐dip galvanized steel sheets in these solutions. These solutions were characterized using high‐resolution transmission electron microscopy and 29Si nuclear magnetic resonance; the morphology of the coatings was observed by SEM and atomic force microscopy while the corrosion resistance was evaluated by electrochemical measurements as well as neutral salt spray tests. The results show that the coatings obtained from the single silica sol solution had poor adhesion and the coating obtained from the sodium silicate solution with low SiO2/Na2O molar ratio was uneven. By adding the silica sol to the silicate solution with low molar ratio, uniform coatings with better protection property were obtained. According to the results of 29Si nuclear magnetic resonance spectra, the effects of the distribution of silicate anions with various polymerization degrees in the silica‐based solutions on the microstructure and corrosion resistance of the silicate coatings are discussed. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
75.
The directional drifting of particles/molecules with broken symmetry has received increasing attention. Through molecular dynamics simulations, we investigate the effects of various solvents on the time-dependent directional drifting of a particle with broken symmetry. Our simulations show that the distance of directional drift of the asymmetrical particle is reduced while the ratio of the drift to the mean displacement of the particle is enhanced with increasing mass, size, and interaction strength of the solvent atoms in a short time range. Among the parameters considered, solvent atom size is a particularly influential factor for enhancing the directional drift of asymmetrical particles, while the effects of the interaction strength and the mass of the solvent atoms are relatively weaker. These findings are of great importance to the understanding and control of the Brownian motion of particles in various physical, chemical, and biological processes within finite time spans. 相似文献
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Dr. Lei Mei Dr. Qun‐yan Wu Dr. Li‐yong Yuan Dr. Lin Wang Shu‐wen An Zhen‐ni Xie Dr. Kong‐qiu Hu Prof. Zhi‐fang Chai Prof. Peter C. Burns Prof. Wei‐qun Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11329-11338
The hierarchical assembly of well‐organized submoieties could lead to more complicated superstructures with intriguing properties. We describe herein an unprecedented polyrotaxane polythreading framework containing a two‐fold nested super‐polyrotaxane substructure, which was synthesized through a uranyl‐directed hierarchical polythreading assembly of one‐dimensional polyrotaxane chains and two‐dimensional polyrotaxane networks. This special assembly mode actually affords a new way of supramolecular chemistry instead of covalently linked bulky stoppers to construct stable interlocked rotaxane moieties. An investigation of the synthesis condition shows that sulfate can assume a vital role in mediating the formation of different uranyl species, especially the unique trinuclear uranyl moiety [(UO2)3O(OH)2]2+, involving a notable bent [O=U=O] bond with a bond angle of 172.0(9)°. Detailed analysis of the coordination features, the thermal stability as well as a fluorescence, and electrochemical characterization demonstrate that the uniqueness of this super‐polyrotaxane structure is mainly closely related to the trinuclear uranyl moiety, which is confirmed by quantum chemical calculations. 相似文献
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