Solubilization in Aqueous Solutions of Hexadecyltrimethyl-ammonium Bromide and Sodium Dodecylsulphate Studied by Nuclear Magnetic Relaxation

Abstract

2H and 14N nuclear magnetic relaxation time measurements have been used to study the dynamics of benzene and cyclohexane molecules solubilized in aqueous CTAB and SDS solutions and the effect of solubilization on the dynamics of the surfactant molecules in CTAB solutions. The rotational diffusion of cyclohexane molecules is found to be 2–3 times slower in the micelles than in the corresponding liquid hydrocarbons. Benzene is found to be solubilized at sites close to the polar surface of the micelles both in CTAB and SDS solutions, but it is only in the case of CTAB solutions that benzene solubilization promotes the formation of long rodshaped aggregates.