The effects of initial surfactant concentration and emulsification time upon the particle size and distribution of benzene-in-water emulsions

Abstract

A new method of studying the particle size distribution of mechanically prepared hydrocarbon-in-water emulsions is described. This method consists of dissolving a small amount of polymer in the hydrocarbon before emulsification, removing the hydrocarbon after emulsification, and counting the resulting polymeric dispersion with the Coulter counter. The diameter of the original emulsion is then computed from these diameters. This method is used to study the particle size of benzene-in-water emulsions as a function of the initial surfactant (sodium dodecyl sulfate) concentration and emulsification time. The steady state particle size of these emulsions is shown to decrease with increasing initial surfactant concentration until the critical micelle concentration (c.m.c.) of the pure surfactant is reached. No further decrease in the steady state particle size occurred using initial surfactant concentrations above the c.m.c. The time to reach a steady state diameter increases linearly with increasing initial surfactant concentration.