Detection of Site-dependent Segmental Mobility of Polymer by Fluorescent Defocused Imaging  

作　　者：De-sheng Li Jing-fa Yang 赵江 

机构地区：[1]Institute of Chemistry, Chinese Academy of Sciences [2]The University of Chinese Academy of Sciences

出　　处：《Chinese Journal of Polymer Science》2017年第12期1488-1496,共9页高分子科学（英文版）

基　　金：financially supported by National Basic Research Program of China(No.2014CB643601)

摘　　要：Polymer chain ends play an important role in the glassy dynamics of polymeric materials. In this study, a combination of single molecule defocus fluorescence microscopy and well-controlled atom transfer radical polymerization was used to investigate site-dependent segmental mobility of poly（n-butyl methacrylate）. As the temperature increased, the rotation of fluorophores, which were selectively labelled in chain end and chain middle, was gradually activated. The power spectra of rotation trajectories, the distribution of angular displacement as well as the population of rotating fluorophores demonstrated that the local dynamics was more activated at the chain ends than the middles, showing the unique contribution of the chain end to the dynamics of the system.Polymer chain ends play an important role in the glassy dynamics of polymeric materials. In this study, a combination of single molecule defocus fluorescence microscopy and well-controlled atom transfer radical polymerization was used to investigate site-dependent segmental mobility of poly（n-butyl methacrylate）. As the temperature increased, the rotation of fluorophores, which were selectively labelled in chain end and chain middle, was gradually activated. The power spectra of rotation trajectories, the distribution of angular displacement as well as the population of rotating fluorophores demonstrated that the local dynamics was more activated at the chain ends than the middles, showing the unique contribution of the chain end to the dynamics of the system.

关 键 词：Glass transition Segmental mobility Chain end effect Fluorescent defocused imaging 

分 类 号：O633.14[理学—高分子化学]