Effect of glycolipids on the stability and electrophoretic mobility of decanoic acid vesicles

Glycolipids, namely heptyl-β-D-glucopyranoside (HG), octyl-β-D-glucopyranoside (OG) and dodecyl-β-D-glucopyranoside (DG), incorporated in sodium decanoate–decanoic acid (SD–DA) aggregates have been found to affect the critical vesicular concentration (CVC) values and electrophoretic mobility behaviour of their vesicles. Titration of the solutions has shown that the buffering capacity from COO−…COOH interaction and multilamellar vesicles was predominantly observed under polarized light microscope for the solutions that have been brought down to neutral pH. CVC of the decanoic acid was reduced to half the initial value (0.02 M) when 4% DG was introduced into the solution, while only a slight change was observed when shorter glycolipids were mixed with the decanoic acid. The glycolipids reduced the electrophoretic mobility of the vesicles possessing a strong interaction between the head groups, which belong to the carboxylate of the fatty acid and hydroxyl of the glycolipids, probably suggesting partial neutralization. Thus, the presence of glycolipids in small amounts promotes the formation of decanoic acid vesicles by enhancing the bilayer curvature through hydrogen bonding within the polar region.