The effect of solubilized water on the size and shape of lecithin micelles in an apolar solvent.

The changes in the size and shape of the micelles of soya lecithin in trichlorotrifluoroethane following the solubilization of increasing quantities of water have been examined by dynamic and static light scattering and viscometric techniques. Micelles in systems with water/lecithin molar ratios. R. of less than 2.6 were oblate and exhibited no significant changes in asymmetry or aggregation number with changes in the amount of solubilized water. Spherical micelles were evident in systems with R = 2.6 whereas prolate micelles were present in solutions of higher water content (3.5 less than or equal to R less than or equal to 5.2). An increase of R in these systems caused a decrease in the axial ratio and an increase in the aggregation number of the micelle.