Abstract:

In this study, self-emulsification method (HLB method) was taken to prepare O/W medium-chain fatty acid (MCFA) micro-emulsions. By means of titration method, it indicated that the titration of the compound of MCFA, surfactant and cosurfactant with distilled water is the best. Through comparison of emulsification efficiency and micro-emulsion area in pseudoternary phase diagram, it was found that the optimal HLB, surfactant, Km value and co-surfactant are 15, single Tween-80, 2:1 and iso-amyl alcohol, respectively. According to the estimation of characteristics of micro-emulsion samples, the formula was optimized as MCFA, Tween-80, iso-amyl alcohol and distilled water in the mass ratios of 3:2:1:0.68. The surface tension, viscidity, conductance, particle size and zeta potential of the obtained micro-emulsion are 26.7142 mN/cm, 65.22 cP, 1.87 μs/cm, 17.3 nm and －7.14 mV, respectively, and its stability is good.

Key words: MCFA, micro-emulsion, pseudo-ternary phase diagram