GELATION OF MICELLAR SOLUTIONS OF DIBLOCK-COPOLY(OXYETHYLENE OXYBUTYLENE) IN AQUEOUS K2SO4 - AN INVESTIGATION OF EXCLUDED-VOLUME EFFECTS/

The micellization and gelation properties of oxyethylene/oxybutylene d iblock copolymers E(40)B(10) and E(41)B(8) in aqueous K2SO4 solutions were investigated. The thermodynamic and hydrodynamic volumes of the m icelles in salt solutions of various concentrations up to 0.4 mol dm(- 3) were determined by static and dynamic light scattering, respectivel y. The related changes in the gelation behavior of concentrated micell ar solutions of the copolymers were explained as thermodynamic (exclud ed) volume effects. The thermodynamic volumes of micelles measured in moderately concentrated solution were used successfully to predict the critical gel concentrations of concentrated solutions. (C) 1995 John Wiley & Sons, Inc.