Influence of Lecithin – Propylene Glycol Intermolecular Interactions at the Water / Vaseline Oil Interphase on the Formation of Self-Organizing Structures

Abstract
The intermolecular interaction of surfactant – co-surfactant in the water – lecithin – propylene glycol – vaseline oil system was investigated. For the first time, two approaches were combined: the principle of hydrophile-lipophile balance (HLB) and the approach that takes into account the interaction parameter for the scientifically justified calculation of the components of the surfactant mixture at the water-oil interface. In mixed systems, synergistic effects of the decrease in interfacial tension were observed. These effects are caused by electrostatic attraction between molecules of zwitterion surfactant (lecithin) and propylene glycol. The main adsorption characteristics of the system were calculated and the critical concentration of micelle formation was determined. The processes of self-organization of a lecithin and propylene glycol mixture at the water / vaseline oil interface have been studied. It was shown that the hydrophile-lipophile balance of the mixture and the interaction parameter exert significant influence on the formation character of liquid crystalline and microemulsion structures.

Keywords: liquid crystals, microemulsions, surfactant mixtures, interfacial tension, adsorption, synergism, hydrophile-lipophile balance, interaction parameter