On the Relation Between Viscosity and Critical Micelle Concentration of Detergent Solutions. II. Viscosity and Diffusion Coefficient of Non-ionic Detergent Solutions

Abstract

(1) Partial specific volume, viscosity, diffusion coefficient of the aqueous solutions of non-ionic detergents are measured.(2) ηsp/C becomes minimum at CMC and this concentration is quite consistent with the concentration where diffusion coefficient varies suddenly. It is interesting that this is the common phenomenon for ionic and non-ionic detergents.(3) The form of ηsp0/C0 vs C0-Curve is analogous to that described in the first report and the second CMC (C2) is also obtained but some abnormality occurs in the part of low concentrations for the substance of which CMC is high.(4) After the completion of micelle formation, diffusion coefficient stays constant and is independent of concentration which suggests that micellar volume is constant and independent of concentration.(5) The influence of an electrolyte on the diffusion is examined and a new idea of the mechanism of “salting out” is proposed.(6) Micellar molecular weight is calculated from the diffusion coefficient assuming that a micelle is spherical.