Surface free energy of organized phospholipid/lauryl gallate monolayers on mica
Year: 2016
Journal: Colloid Surf. A-Physicochem. Eng. Asp.
Authors: Jurak, M
Surface free energy and its components of the Langmuir-Blodgett (LB) films of phospholipids (PL) and lauryl gallate (LG) were estimated to characterize the monomolecular films properties. They were determined from the contact angle measurements of chosen liquids, and applying the theoretical models proposed by Chibowski and van Oss et al. The averaged values of the total surface free energy from the Chibowski approach are mainly in line with the mean values from the van Oss et al. approach but the former are found to be higher due to the interactions from closer molecular spacing. Moreover, the differences between them increase with the increasing LG in the PL monolayers and particularly depend on the saturation/unsaturation of acyl chains in the phospholipid molecules which affects the mixed monolayer packing and ordering. The obtained results indicate that stability and permeability of the binary films deposited on mica depend on the chemical composition and stoichiometry of the mixed monolayers. That provided better understanding of organization structure of the model membranes and their interactions with the surroundings. These results may be helpful to get insight into LG behaviour in living systems in view of membrane antioxidant protection and pharmacological activities. (C) 2016 Elsevier B.V. All rights reserved.
