Flocculation studies of granulated stearyl alcohol on the surface of aqueous media. II. Flocculation-deflocculation mechanism in a two-dimensional system.

Abstract

The flocculation-deflocculation mechanism of granulated stearyl alcohol dispersed on the surface of aqueous media in the presence of surface-active agents was examined. The flocculation rate was estimated on the assumption of a second-order rate process. The flocculation rate decreased at first, and then increased to the maximum value with increasing concentration of the surface-active agent. Thereafter, the flocculation rate decreased, and reached an almost constant value. The profiles of change of the flocculation rate with concentration of surface-active agent in the systems containing various kinds of surface-active agents were similar. However, taking account of the critical micelle concentration, the profiles could be classified into two patterns. One reason for the difference between the profiles was supposed to be the difference in structure of the surface-active agents. The flocculation behavior is discussed in relation to the effects of hydrophobic interaction, electrorepulsive force and steric hindrance.