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Your search keyword '"Zheng, Chunbai"' showing total 19 results
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19 results on '"Zheng, Chunbai"'

13. DGEBA/imidazolium ionic liquid systems: the influence of anions on the reactivity and properties of epoxy systems.

Author

Yin, Yuan, Liu, Meihua, Wei, Wei, Zheng, Changmei, Gao, Jian, Zhang, Wanxi, Zheng, Chunbai, Deng, Pengyang, and Xing, Yue

Subjects
IMIDAZOLES, SALTS, POLYMERS, BISPHENOL A, ANIONS
Abstract

Imidazolium salts containing , , , , or ionic liquids were blended with an epoxy prepolymer, dyglycidylether of bisphenol A (DGEBA) to obtain a series of compositions. To characterize the resulting mixtures and determine the influence of the imidazolium anion on the reactivity and properties of epoxy systems, we performed the following analyses and tests: (i) differential scanning calorimetry (DSC), to determine the curing reaction characteristics, (ii) in situ fourier-transform infrared spectroscopy (FTIR), to assess chemical structure changes, (iii) mechanical property testing of the hardened epoxy material, and (iv) thermogravimetric analysis (TGA). The DSC and FTIR analyses indicate that [Hmim]BF4, and [Hmim]PF6 cannot induce the epoxy ring opening reaction and thus these materials are unable to function as epoxy curing agents. In contrast, the imidazolium ionic liquids [Hmim]FeCl4, [Hmim]N(CN)2, and [Hmim]Zn2Cl5 independently promote the epoxy ring opening reaction. TGA analyses show that the cured DGEBA/[Hmim]Zn2Cl5 system exhibits thermal stability similar to the cured DGEBA/[Hmim]FeCl4. These results can provide an essential reference not only for studying the synergistic effect of [C6mim]FeCl4/mixed-amines on the curing process of epoxy systems and the mechanism of the ring opening of epoxides with [C6mim]FeCl4/mixed-amines, but also for designing new epoxy curing systems. [ABSTRACT FROM AUTHOR]

Published
2018
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19. Continuous ultrathin UiO-66-NH 2 coatings on a polymeric substrate synthesized by a layer-by-layer method: a kind of promising membrane for oil-water separation.

Author

Gao J, Wei W, Yin Y, Liu M, Zheng C, Zhang Y, and Deng P

Abstract

In this paper, we successfully controllably synthesize continuous nanothickness MOF coatings (NTMCs) by a layer-by-layer method on a polymeric substrate. The polymeric substrate was pretreated with high energy γ-irradiation to induce a high surface density of living reactive groups, which ensure the formation of continuous surface-integrated NTMCs. SEM, FT-IR spectroscopy and XPS were used to characterize NTMCs. The thickness and morphology were tuned by the LBL cycles, and NTMCs with a thickness of ∼44 nm were obtained. The chemical bonds between the NTMCs and polymeric substrate were confirmed by XPS and EDS. Moreover, the NTMCs exhibit good performance for oil-water separation. We believe that our work will promote the design and precise synthesis of high-performance MOF based membranes for multiple practical applications in future.

Published
2020
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