Study on formation and stability of colloidal liquid aphrons

In an attempt to explore the nature and structure of colloidal liquid aphrons (CLA), the formation and stability of CLA composed of polyoxyethylene 3 dodecyl ether (AEO-3)/n-decane/sodium dodecyl sulphate (SDS)/water were investigated using the conductivity technique and microscopic observations. The formation mechanism and the stability behavior of CLA were derived from the conductivity profiles and verified by the optical micrographs. It was found that the formation was a low-energy emulsification process including a foaming stage and then the exchange of the gas for oil phase. No phase inversion took place during the whole formation process, hence the CLA represented O/W emulsion type. The stability behavior determined by conductivity analysis was described using linear equation at 303.15 K. As the temperature is above 318.15 K, the conductivity profiles of CLA, which presents a different kinetics from the first order model, conformed to the sigmoidal equation sigma(t) = sigma(1)-sigma(2)/1+e((t-t0)/S)+sigma(2), where sigma(t) refers to the conductivity at time t, sigma(1) and sigma(2) refer to the minimum and maximum conductivity during storage, respectively, to is the time