Kinetic Rate Constant of Liquid Drainage from Colloidal Gas Aphrons

A kinetic model fitted by the empirical equation has been proposed to describe the liquid drainage behavior. Rate constants (kd) of liquid drainage equation could be obtained from the above empirical equation. In this paper, the stability of the colloidal gas aphrons (CGAs), the effect of concentrations of sodium dodecyl benzene sulphate (SDBS), dodecyl trimethylammonium bromide (HTAB) and polyoxyethylene sorbitol anhydride monolaurate(Tween-20), temperature, stirring speed, stirring time, and various kinds of salts on the kd of liquid drainage are further investigated. The results show that the Arrhenius equation can be successfully used to describe the relation between kd and absolute temperature (T), and concentrations of surfactants, stirring speed, stirring time and salinities also have great effect on the kd. At last, the CGAs drainage mechanism is explained from analysis of the rate of liquid drainage as a function of time.