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A Pronounced Halogen Effect on the Organogelation Properties of Peripherally Halogen Functionalized Poly(benzyl ether) Dendrons 下载免费PDF全文
Prof. Dr. Yu Feng Hui Chen Zhi‐Xiong Liu Yan‐Mei He Prof. Dr. Qing‐Hua Fan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4980-4990
An interesting halogen‐substituent effect on the organogelation properties of poly(benzyl ether) dendrons is reported. A new class of poly(benzyl ether) dendrons with halo substituents decorating their periphery was synthesized and fully characterized. A systematic study on the gelation abilities, thermotropic behaviors, aggregated microstructures, and mechanical properties of self‐assembled organogels was performed to elucidate the halogen‐substituent effects on their organogelation propensity. It was found that the exact halogen substitutions on the periphery of dendrons exert a profound effect on the organogelation propensity, and dendrons G n ‐Cl (n=2, 3) and G2‐I proved to be highly efficient organogelators. The cooperation of multiple π–π, dispersive halogen, CH–π, and weak C?H ??? X hydrogen‐bonding interactions were found to be the key contributor to forming the self‐assembled gels. Dendritic organogels formed from G n ‐Cl (n=2, 3) in 1,2‐dichloroethane exhibited thixotropic‐responsive properties, and such thixotropic organogels are promising materials for future research and applications. 相似文献
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He Haidong Yang Haifeng Zhou Longpeng Chen Tianchi 《Journal of Russian Laser Research》2015,36(3):292-299
Ni–Co alloys have a wide range of applications in various fields owning to their excellent physical, chemical, and mechanical properties. In this paper, we prepare Ni–Co alloy coatings on 316L stain steel surfaces by electroplating. We present a novel approach utilizing a nanosecond laser to induce microtextures on Ni–Co alloy coatings. We study experimentally the effects of laser power and scanning rate on the surface morphologies of Ni–Co alloy coatings. The results indicate that the shape and size of induced microtextures can be controlled by the laser power and scanning rate. The size of grains increases with increase in the work current of the laser (WCL) at a certain scanning rate. With the WCL constant, the size of grains decreases with increase in scanning rate while their average height increases. It is a simple and easily-controlled method for the fabrication of microstructures on Ni–Co alloy coatings, which has promising applications in investigations of the properties of microtextured surfaces, such as friction, adhesion, and wetting. 相似文献
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Generation of Oxazolidine‐2,4‐diones Bearing Sulfur‐Substituted Quaternary Carbon Atoms by Oxothiolation/Cyclization of Ynamides 下载免费PDF全文
Hai Huang Junzhen Fan Dr. Guangke He Zhimin Yang Xiaodong Jin Qi Liu Prof. Dr. Hongjun Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(7):2532-2538
A novel method for metal‐free oxothiolation of ynamides to construct oxazolidine‐2,4‐diones bearing sulfur‐substituted quaternary carbon atoms has been developed. It represents a rare C?O bond cleavage of ynamides, as well as a facile and tandem approach for the formation of C?O, C?S, and C?Cl bonds. This redox‐neutral protocol can be applied to the synthesis of multisubstituted oxazolidine‐2,4‐diones with good chemoselectivity and good yields of isolated products under mild conditions. 相似文献
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Ziyi Yu Jing Zhang Roger J. Coulston Richard M. Parker Frank Biedermann Xin Liu Oren A. Scherman Chris Abell 《Chemical science》2015,6(8):4929-4933
Host–guest assembly in droplet-based microfluidics opens a new avenue for fabricating supramolecular hydrogel microcapsules with high monodispersity and controlled functionality. In this paper, we demonstrate a single emulsion microdroplet platform to prepare microcapsules with supramolecular hydrogel skins from host molecule cucurbit[8]uril and guest polymer anthracene-functionalized hydroxyethyl cellulose. In contrast to construction of microcapsules from a droplet-in-droplet double emulsion, here the electrostatic attraction between charged polymer and surfactant facilitates formation of defined supramolecular hydrogel skins in a single emulsion. Furthermore, by taking advantage of dynamic interactions and the tunable cross-linked supramolecular hydrogel network, it is possible to prepare microcapsules with triggered and UV-controlled molecular permeability. These could be potentially used in a delivery system for e.g. agrochemicals, nutraceuticals or cosmetics. 相似文献
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