首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Concentration Effects in Sec for Polymer/Polymer/Solvent Systems
Abstract:Abstract

A model quantitatively describing the experimental shifts in elution volumes of polymeric solute A in the presence of another polymer B is developed. The concentration-dependent shrinkage of A coils has been evaluated from the intrinsic viscosity displayed by polymer A in the ternary solution formed by itself at cA concentration + polymer B at cB concentration + solvent. Resulting concentration effects depend on both polymer concentrations (cA and cB), on the intrinsic viscosities of both polymers in the solvent (|η|A and |η|B), on the Huggins' coefficients kA and kB, and on the quadratic concentration coefficients in the polynomial expansion of ηsp/c, namely k A and k B. Predicted elution volumes are compared with experimental ones for two different types of literature systems: those studying polymer A elution at diverse cA concentrations in eluents consisting of mixtures of polymer B + solvent and those in which polymer A + polymer B mixtures are injected at once in the pure solvent used as eluent. In order to eliminate experimental uncertainties about ki and k i (i=A, B) values, applied k i values were those obtained from the empirical correlation k i + 0.122 = ki 2 whereas ki ones were obtained from Imai's equation.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号