Microemulsion Formation of Vegetable Oils Using Mixed Extended Surfactant for Cleaning Applications

Abstract

Some vegetable oils and animal fats can form semi-solid crystalline. The formation of semi-solid fats or waxy soils results in weak interactions between the oil and surfactant during the cleaning process. In this study, the anionic extended surfac-tant (C14-15, 8PO-SO4) systems were employed to form a middle phase microemul-sion with various vegetable oils (coconut, palm and soybean oil). The addition of nonionic extended surfactant (C16-18, 2PO-4EO-OH) in the mixed surfactant systems was also evaluated to observe the solubility enhancement of oil and water phase. The IFT value of formulated surfactant systems was measured to determine the optimum salinity. The Hydrophilic-Lipophilic Deviation (HLD) concept was conducted to es-timate the required Cc and K parameter for examination of the correlation with the experiment. It was found that the extended surfactant systems formed the middle phase microemulsion with coconut, palm and soybean oil at the optimum salinity of 7 wt%, 8 wt% and 9 wt% NaCl, respectively. For the mixed system with the nonionic surfactant, the middle phase microemulsion formed at lower optimum salin-ity than that of the single surfactant system. The negative Cc value that obtained from HLD equation indicated that the hydrophilic surfactant property. For hard sur-face cleaning, the oil removal efficiency of mixed surfactant system is higher than the single surfactant system alone. The results obtained in this study improve the bet-ter understanding of the surfactant selection for vegetable oil microemulsions as well as semi-solid fats in cleaning application.