Vesicle adsorption on SiO2 and TiO2: Dependence on vesicle size

Kinetics of vesicle adsorption on SiO2 and TiO2 surfaces was investigated for vesicle sizes from 25 to 200 nm. On SiO2, nonruptured vesicles are adsorbed up to a critical coverage, Θc, after which spontaneous rupture and bilayer formation occurs in qualitatively the same manner for all vesicle sizes. On TiO2, adsorption of nonruptured vesicles continues up to saturation. A comparison between the kinetics at low coverages on SiO2 and TiO2, where intact vesicles adsorb on both surfaces, reveals that the vesicles on SiO2 are more flattened than nonruptured vesicles adsorbed on TiO2, indicating a stronger vesicle-surface interaction on SiO2.