Industrial & Engineering Chemistry Research, Vol.50, No.21, 11889-11896, 2011
Temperature Induced Emulsification and Demulsification of Pseudoternary Mixtures of Tween80-Butanol-Kerosene-Water System
The phase diagrams of pseudoternary mixtures of Tween80-butanol-kerosene-water system were constructed by visual titration. The major three domains, i.e., oil in water, bicontinuous, and water in oil microemulsions were demarcated through conductivity measurement. A sharp increase in specific conductance in increasing water content in the bicontinuous domain has been ascribed to the percolation of ions through water continuum. Temperature induced clouding behavior of the mixtures in the Winsor IV domains was investigated to find out the effect of composition on the clouding temperature. A generalized regression model was proposed considering the cloud point to be a function of surfactant/cosurfactant ratio and oil and emulsifier contents. The increase in all these parameters increases the cloud points of the mixture. In the turbid Winsor LIT domain, temperature has an emulsifying effect. With increase in temperature, the turbid phase separates to three different phases, which experience transparent, translucent, and turbid characteristics due to mass transfer from one phase to another. The mass transfer phenomenon was well visualized by using nickel as water-soluble and N-alkyl 4-(p-N,N-dimethylaminostyryl)pyridinium dyes as oil-soluble probes.