荧光关联光谱在高分子单链研究中的应用

荧光关联光谱(fluorescence correlation spectroscopy,FCS)是一项用于研究体系动力学性质的统计光谱技术,随着它被引入材料与化学研究领域,近年来取得了大量全新的研究成果.该技术在高分子科学研究中也逐渐发挥出越来越大的作用,特别是在聚合物结构和动力学方面,这表明它在高分子领域的巨大潜力.本文将从FCS的基本原理、实验技巧以及在一些具有挑战性体系中的应用等方面展开,着重介绍它在高分子溶液,如聚电解质溶液、高分子混致不溶现象,以及不同的表界面体系中取得的新成果,展示FCS区别于其他传统技术的特点和优势.

Applications of Fluorescence Correlation Spectroscopy in the Study of Single Chains of Polymers

Fluorescence correlation spectroscopy(FCS)is a statistical spectroscopy technique mainly used to study the dynamics of systems under thermal equilibrium.This technique is extremely sensitive and has excellent spatial and temporal resolution,making it very powerful in studying the dynamics of systems under thermal equilibrium,especially measuring translational diffusion of single molecules,in solutions and at interfaces.In recent years,there have been significant contributions of FCS to the investigations in the field of materials and chemistry researches,and a large number of new researches have been successfully conducted.In polymer science,this technology plays increasingly important roles,especially in polymer structure and dynamics.This review will cover many aspects of FCS,including the principles of FCS,the basic theory and the instrumentation of FCS.Experimental skills have also been introduced.Attention is paid to the applications of FCS in a few fields that are challenging to conventional methods such as dynamic scattering.The investigations by FCS have been introduced into polymer solutions,including polyelectrolyte solutions and cononsolvency of neutral polymers,and lateral diffusion of single polymer molecules at surfaces and interfaces,as well as the coupling of translational diffusion among charged macromolecules.It has been demonstrated that due to the extreme sensitivity,the FCS experiments are conducted at extreme dilution,making effective measurements of individual charged molecules and providing important information on the chain conformation and its transition.The advantage of FCS has also been shown to creat long enough time window for single molecule measurements.Under such conditions,diffusion of single polymer molecules can be measured while they are supposed to precipitate under experimental condition of conventional methods.The effectiveness of FCS in studying translational diffusion has also been demonstrated,showing the powerfulness of FCS in multiple dimensional measurements.All of the examples provided in the current review help to highlight the characteristics and advantages of FCS that distinguish it from other traditional technologies.It is believed that FCS can continue to enjoy its effectiveness in a number of fields in polymer researches.