ANALOGY BETWEEN AQUEOUS-SOLUTIONS OF SURFACTANT MICELLES AND SEMIDILUTE POLYMER-SOLUTIONS

By static and dynamic light scattering, were measured osmotic compressibility, static correlation length, and hydrodynamic correlation length of aqueous solutions of heptaethyleneglycol monotetradecyl ether(C14E7) as a function of concentration ranging from 1 x 10(-3) g .ml-1 to 0.1 g.ml-1 at various temperatures ranging from 35 to 55-degrees-C. To make a quantitative examination of applicability of scaling and screening concepts to micellar systems, the results were compared with those of semidilute solutions of polystyrene in t-decalin near the theta-temperature with the aid of equations proposed here on the basis of the scaling theories for polymer solutions. The following conclusions have been deduced : (1) The present micellar solutions are not in the asymptotic scaling region, but in the crossover region from the poor- to good-solvent regions. (2) Osmotic compressibility and static correlation length of the micellar solutions can basically be described by the equations presented here covering the critical and the tri-critical semidilute regions, in common with those of polymer solutions. (3) Molecular parameters in these equations obtained suggest increase in the statistical segment length with increasing temperature.