Differences in Thinning Processes of Some Vesicular Foam Films with Different Compositions

Thinning processes of foam films are observed for various phospholipid vesicle suspensions by the horizontal suspending method using an interferometric microscopy system. It is found that the phospholipid components that construct the bilayer of unilamellar vesicles or micelles affect the thinning process behavior of the plane-parallel liquid film. In the case of vesicle from egg phosphatidylcholine (PC), the plane-parallel foam film made of its suspension shows a gradual but inhomogeneous slow thinning process, which differs from the stepwise thinning process of thin liquid films with silica or micelle suspensions reported in previous investigations. However, when lysophosphatidylcholine was mixed with egg PC, channel formation and coexistence of black thin films and thicker regions were observed. Copyright 1998 Academic Press.