Characterization of dioctadecyldimethylammonium chloride vesicles prepared by membrane extrusion and dichloromethane injection.

Vesicles of dioctadecyltrimethylammonium chloride were prepared by sonication, membrane extrusion and dichloromethane injection. The diameter of the vesicles were determined using quasi-elastic light scattering and freeze fracture electron microscopy. The incorporation of water soluble probes in the vesicles allowed the determination of a molar volume of 6 to 8 L/mole for the CH2Cl2 injected vesicles and 1.0 L/mole for the membrane extruded vesicles, in very good agreement with the data calculated from the vesicle diameters. The permeability of the injected CH2Cl2 vesicles is dependent on temperature and probe structure. Membrane extruded vesicles are more permeable than injected vesicles, both below and above the phase transition temperature. (C) 1997 Elsevier Science B.V.