Effect of acidity on the formation of solvent-free lipid bilayers

Abstract

Glasses with hydrophobized surface are used to form “dry” bilayer lipid membranes (BLM). The contact angle on the silaned glass plates reaches 125°. Partitions of this kind, as opposed to polymer films, make a system more resistant to heat oscillations and mechanical perturbations generated when studying membranes properties. The specific capacitance of BLM (0.86 ± 0.04 μF cm⁻²) testifies to the solvent absence in the bilayer. The dramatic drop of the capacitance (area) of the dry membranes with increasing pH is caused by a greater adsorption of lipid molecules on the hydrophobic substrate, which is probably due to changing conformation of their polar “head.”