Micellar structure and intermicellar interactions in solutions of tetradecyltrimethylammonium bromide in the presence of 1-pentanol: Light scattering and viscosity study

Abstract

Micellar solutions of tetradecyltrimethylammonium bromide in H 2O-0.1 M KBr and in the presence of 1-pentanol have been investigated by means of elastic and quasi-elastic light scattering and viscosimetry at moderate to high surfactant concentration. The viscosity measurements have confirmed the existence at a very low micelle concentration of a maximum of pentanol solubilization by the micelles. The changes of intensity of scattered light, of the viscosity of the solution and of the micelle diffusion coefficient, with the surfactant and alcohol concentrations have been determined. The results in the absence of pentanol confirm that the repulsive interactions between micelles affect the above properties in the order: diffusion coefficient < viscosity < frictional coefficient < intensity of scattered light. The results in the presence of pentanol have been discussed in terms of micelle swelling by pentanol, micelle anisotropy induced by pentanol solubilization, and changes of intermicellar repulsive interactions.