Study by Light Scattering of the Effect of the Surfactant Chemical Structure on Micellar Interactions of Water/Oil Microemulsions

Article abstract of DOI:10.1021/j100254a026

Light scattering and photon correlation spectroscopy have been utilized in studying the effect of the surfactant chemical nature on micellar interactions in W/O microemulsions.Specifically, the surfactant chemical structure has been altered at the molecular level by adding a ramification near the polar head group.This influence of surfactant structure on micellar interactions has been examined through a series of five homologues of SDS, each variation containing a larger ramification.Analysis of the dispersed phase composition and the light-scattering data indicates that the amphiphilic surface ara occupied per surfactant molecule (including the alcohol contribution) is constant.The increase in the individual surfactant molecule polar head surface area is balanced by a decrease in the alcohol content of the interfacial film.As one proceeds through the SDS series, a definite decrease (from positive to largely negative) has been found for values of second virial coefficients.In terms of attractive potential, this indicates an evolution from hard spheres to largely attractive spheres.