Physicochemical Behaviour of Ternary System Based on Coconut Oil/C12E8/n-pentanol/water

Physicochemical properties of a system based on Coconut Oil, nonionic surfactant C₁₂E₈, cosurfactant n-pentanol and water has been studied. The phase behavior, effect of temperature and electrical conductivity of the system was studied at different surfactant (S) to cosurfactant (C) ratios, the ratios being 1:1, 1:1.5, 1:2 (w/w). Pseudoternary phase behavior of these ratios was studied, the phase diagrams generated distinguishes between monophasic/isotropic and biphasic/anisotropic regions. The monophasic region was found to be a strong function of the S:C ratio. The largest monophasic region was obtained when the S:C ratio was 1:1, the monophasic region gradually depleted with decrease in amount of S in the order 1:1 > 1:1.5 > 1:2. The effect of temperature was examined on the phase behavior of the system, and for all S:C ratios it was observed that the monophasic region decreased with increase in temperature. The electrical conductivity of the system increases with aqueous phase content indicating a transition from water-in-oil to oil-in-water microemulsions.