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Your search keyword '"Cheng, Si"' showing total 14 results
Start Over Author "Cheng, Si" Journal macromolecular rapid communications
14 results on '"Cheng, Si"'

10. A Platform for Preparation of Monodispersed Fluorescent Conjugated Polymer Microspheres with Core-Shell Structures.

Author

Wang, Shangli, Fan, Li-Juan, Song, Jing, Zhao, Wei, and Cheng, Si

Subjects
FLUORESCENT polymers, CONJUGATED polymers, MICROSPHERES, MICROFABRICATION, CROSSLINKED polymers, FLUORESCENCE
Abstract

A strategy to prepare stable monodispersed fluorescent microspheres is developed by modifying the Wessling method to synthesize poly(p-phenylenevinylene) (PPV) on the surface of a highly crosslinked polymer core. The positively charged PPV polymer precursors (pre-PPV) are adsorbed onto the core with negative charges on the surface and then the insoluble fluorescent PPVs form after thermal elimination. Each individual sphere is found to possess a very smooth surface with an even distribution of fluorescence by microscopic techniques. Very small coefficient of variance (CV) values of emission intensity (<4.0%) and size (<2.3%) are realized for microspheres prepared in the same batch. The spheres are demonstrated to have good thermal stability and photostability. [ABSTRACT FROM AUTHOR]

Published
2013
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13. Modular Synthesis of Thermosensitive P(NIPAAm‐co‐HEMA)/β‐CD Based Hydrogels via Click Chemistry

Author

Xu, Xiao‐Ding, Chen, Chang‐Sheng, Lu, Bo, Wang, Zong‐Chun, Cheng, Si‐Xue, Zhang, Xian‐Zheng, and Zhuo, Ren‐Xi

Abstract

Two kinds of representative polymers, poly(N‐isopropylacrylamide) (PNIPAAm) and β‐cyclodextrin (β‐CD) were selected and modified with azide and alkyne fucntional groups, respectively. When the solutions of these two modified polymers were mixed together, a cross‐linking reaction, a type of Huisgen's 1,3‐dipolar azide‐alkyne cycloaddition, occurred in the presence of Cu(I) catalyst. The strategy described here provides several advantages for the hydrogel formation including mild reaction conditions and controllable gelation rate. The resulted hydrogels were studied in terms of scanning electric microscopy (SEM), equilibrium swelling ratio and swelling/shrinking kinetics. The data obtained demonstrated the hydrogels had a porous structure as well as favorable thermosensitivity.

Published
2009
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14. The Effect of –(C<INF>6</INF>F<INF>4</INF>)– on the Surface Free Energy of Main-Chain Liquid Crystalline and Crystalline Polymers

Author

Chung, Tai-Shung, Ma, Kui-Xiang, and Cheng, Si-Xue

Abstract

Novel fluorinated main-chain liquid-crystalline/crystalline polymers were prepared through thin film polymerization to investigate the effect of –(C6F4)– on the surface free energy. The fluorine in the phenyl rings does not lower the total surface free energy of the thin copolymer films, compared to those without fluorine. Interestingly, the Lewis acid components (γ+) of the surface free energy of the fluorine-containing polymers increase with an increase in the –(C6F4)– content, indicating the increasing electron accepting character of the surface.

Published
2001
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