关键词: 大豆卵磷脂, 二元相行为, 三元相行为, 液晶

Abstract:

The studies of the phase behavior of lecithin systems are of great significance for understanding the formation mechanism of liquid crystal systems. Such studies include the phase transition under different conditions as well as the aggregate structure induced by intermolecular interactions. To find the rule for the formation of liquid crystal structure of soybean lecithin, the effects of co-emulsifiers on the phase changes for different mass fractions of lecithin at different temperatures were investigated in the form of binary phase diagrams. The results showed that after mixed with cholesterol, soybean lecithin at mass fraction range of 20%-35% at room temperature could form liquid crystal exhibiting regular and bright Maltese crosses. The effects of oil type and content on the formation of liquid crystal structure of lecithin systems were studied by pseudo-ternary phase diagram. It was found that for the case of a single oil, those ester oils （e.g., GTCC and JOJOBA） would contribute to the formation of liquid crystal structure in the emulsion. The phase region of liquid crystal-structured emulsion was the largest area for the case of 16%-20% mixed oils （m（white oil）∶m（GTCC）∶m（JOJOBA）=1∶1∶1）, and the Maltese crosses denoting liquid crystal structure were bright. The oscillatory rheological test showed that the linear viscoelastic region of liquid crystal emulsion was larger than that of ordinary emulsion, indicative of better stability.

Key words: soybean lecithin, binary phase diagram, ternary phase diagram, liquid crystal