KINETICS OF AIR VESICLE-SUSPENSION/QUARTZ 3-PHASE CONTACT/

The stability of thin liquid films of vesicle suspensions in water for med on a quartz surface is studied by measuring the film lifetime tau and the kinetics of the three-phase contact line formed after the film rupture. The experiments were performed at two temperatures, 20 and 3 0 degrees C, spanning the melting phase-transition temperature T-c of the DMPC lipid used. At the upper temperature it is observed that tau exhibits a pronounced minimum as a function of the vesicle concentrati on, whereas the dynamic contact angle shows a maximum. To explain the experimental results, the existence of a specific hydrophobic attracti ve force between the film surfaces is required. Thus, a scenario for t he film rupture is proposed that provides an explanation of the result s above T-c and of the unlimited stability of the films below T-c. (C) 1998 Elsevier Science B.V.