光散射技术在高分子表征研究中的应用  

Laser Light Scattering and Its Applications in Polymer Characterization

作　　者：郑萃 刘芷君 梁德海[2] Cui Zheng;Zhi-jun Liu;De-hai Liang(SINOPEC Beijing Research Institute of Chemical Industry,Beijing 100013;College of Chemistry&Molecular Engineering,Peking University,Beijing 100871)

机构地区：[1]中国石化北京化工研究院,北京100013 [2]北京大学化学与分子工程学院,北京100871

出　　处：《高分子学报》2022年第1期90-106,共17页Acta Polymerica Sinica

摘　　要：光散射技术是高分子领域中重要的表征手段之一.静态光散射和动态光散射的结合能够获得丰富的关于高分子的信息,如重均分子量、回转半径、第二维里系数、流体力学半径、尺寸分布、分子链构象等.除合成高分子外,光散射技术同样适用于研究生物大分子、微生物、胶体、纳米粒子、病毒、囊泡等在溶液或悬浮液中的行为.本综述重点介绍稀溶液中静态光散射和动态光散射的历史、基本理论和实验技巧.对于浓溶液适用的交叉相关技术和扩散波谱技术以及固体光散射也做简要介绍.为了帮助初学者更好地理解并掌握光散射技术,综述的最后介绍了4个应用实例:动、静态光散射相结合跟踪研究线团到密实球的转变过程,光散射确定超支化分子的标度关系,时间可分辨的光散射来剖析聚合诱导胶束化的机理,以及去偏振动态光散射研究纳米粒子在生物介质中的聚集行为.Laser light scattering(LLS),which includes static light scattering(SLS)and dynamic light scattering(DLS),has been widely applied in characterization of polymer samples in dilute solutions.SLS measures the angular dependence of the excess scattered intensity,from which the weight average molecular weight,radius of gyration,and second viral coefficient are obtained.DLS measures the intensity-intensity time correlation functions,from which the hydrodynamic radius and size distribution are obtained.The combination of SLS and DLS enables information on chain conformation.Beside synthetic polymers,LLS is also suitable for the solutions and suspensions of biopolymers,microbial,colloids,nanoparticles,virus,and vesicles.The history,theory,and experimental techniques of SLS and DLS specific for dilute solutions are summarized.In recent years,the cross correlation techniques,diffusing wave spectroscopy,and other related techniques have been developed to expand LLS to study samples in semi-dilute and even concentrated solutions.These techniques,as well as solid light scattering,are also briefly introduced in this review.In the last,we provide four typical examples of light scattering experiments:the coil-to-globule transition as studied by the combination of SLS and DLS,the scaling of hyperbranched polymers as determined by LLS,the polymerization-induced micellization process as monitored by time-resolved LLS,and the aggregation of nanoparticles in biological media as investigated by depolarized DLS.

关 键 词：光散射 高分子表征 分子量 回转半径 相关函数 

分 类 号：TQ317.2[化学工程—高聚物工业]