高分子体系中溶剂扩散系数测定方法的研究进展

摘要

探明高分子体系中溶剂小分子扩散系数的测定方法,对传质过程的深入研究及在膜分离、溶剂萃取等不同的科学工程领域具有非常重要的意义.高分子体系中溶剂分子扩散的两种基本形式为自扩散与互扩散,测定自扩散系数的方法主要有脉冲梯度核磁共振法(PFG-NMR),反气相色谱法等,测定互扩散系数的方法主要有重量法,傅里叶变换红外衰减全反射(FTIR-ATR)等.这些测试方法在测量时间、准确度和适用浓度范围等方面都有各自的应用优势.本文重点介绍了各测试技术的基本特点和最新应用进展,并指出了各测试技术的适用范围以及目前存在的问题,并对它们的改进方向进行了展望,以期为研究者采用易操作、成本低、快速准确的测试方法提供参考依据.%The determination method of small molecule diffusion coefficients of solvent in polymer systems is of great importance for the further study of mass transfer processes and in the fields of membrane separation,sol-vent extraction and other scientific engineering fields.The two basic forms of solvent diffusion in polymer systems are self-diffusion and inter-diffusion,the methods of determing self-diffusion coefficients include pulse gradient nuclear magnetic resonance(PFG-NMR)and Inverse gas chromatography,etc;the methods of determining inter-diffusion coefficients are Gravimetric method and Fourier transform infrared attenuated total reflection(FTIR-ATR),etc.Each determination method has its own advantages in terms of measurement time,accuracy and ap-plicable concentration range.The basic characteristics and latest application progress of each determination method were introduced,the applicable range and the existing problems of each determination method were also pointed out,and the direction of their improvement was prospected,hoping to provide reference for researchers to adopt easy-operate,low cost,fast and accurate determination methods.