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測(cè)量應(yīng)用案例-77-200SM
閱讀：255 發(fā)布時(shí)間：2015-9-11| 提 供 商 | 美國(guó)布魯克海文儀器公司 | 資料大小 | 0K |
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文獻(xiàn)名： “Sergeants and soldiers rule” in helical substituted polyacetylene-derived copolymer nanoparticles
作者： Biao Zhao, Chunni Chen, Huajun Huang, Jianping Deng
摘要：This article reports on the catalytic emulsion copolymerizations of chiral/achiral substituted acetylene monomers. An achiral N-propargylamide monomer underwent copolymerizations separay with two enantiopure monomers of chiral N-propargylsulfamide in the presence of (nbd)Rh+B−(C6H5)4 as catalyst and with Triton X-100 as emulsifier. The obtained (co)polymer emulsions demonstrated high stability and optical activity. Transmission electron microscopy (TEM) and gel permeation chromatography (GPC) techniques in combination demonstrated the successful formation of nanoparticles (100?300 nm in diameter) constructed by copolymers. Circular dichroism and UV-vis absorption spectra showed that the (co)polymer chains in the nanoparticles adopted helical structures of a predominant helicity, which enabled the copolymer nanoparticles to show optical activity. Compared to the corresponding nanoparticles of the homopolymers, the nanoparticles constructed by the copolymers exhibited blue shifts in circular dichroism (CD) and UV-vis spectra. The present study demonstrated that the copolymers prepared via emulsion polymerization approach followed the “sergeants and soldiers rule.”
關(guān)鍵詞：Emulsion polymerization;Helical polymer;Optical activity;Sergeants and soldiers rule