Apparent Dipole Moments of Aerosol OT Reversed Micelles in Cyclohexane Determined at a Frequency of 1 MHz and at a Temperature of 298.15 K

Abstract

Precise determinations of dielectric constants were carried out for Aerosol OT reversed micelles in cyclohexane at a frequency of 1 MHz and at a temperature of 298.15 K for molalities of AOT from 0 to 0.04 mol kg−1. The ratio of the amount of water,r, to that of AOT was varied from 0 to 25 and the apparent dipole moments for the mixed solute (AOT +r·H2O) were calculated. Discontinuous change in the limiting dipole moment with increasingrwas found and was related to the characteristic of water to bind to the head group of AOT. The process of forming W/O microemulsion and the molecular interactions in the micellar core are discussed in terms of the hydration of AOT.