EFFECT OF SOLVENT ON CONCENTRATION-DEPENDENCE OF HYDRODYNAMIC VOLUMES AND GPC ELUTION VOLUMES

The models of Yamakawa and Rudin were used to predict the effects of polymer concentration on hydrodynamic volumes of solvated macromolecules and on peak elution volumes in gel-permeation chromatographic (GPC) analyses. Both theories predict GPC behavior accurately for all systems of practical analytical interest. Yamakawa theory calculations predict that a concentration region may exist in which the polymer hydrodynamic volume may be greater in a poorer solvent than in a thermodynamically better solvent. This “cross-over” is noticeable for high molecular weight polymers at relatively high concentrations which are beyond the dilute region for which the theory was developed. Some GPC observations with porous glass packings are nevertheless in qualitative agreement with this prediction. Both models account for the effects of concentration, solvent choice, and polymer molecular weight on GPC column behavior. © 1979, The Society of Polymer Science, Japan. All rights reserved.