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 inte rferometric microscopy system. It is found that the phospholipid compo nents that construct the bilayer of unilamellar vesicles or micelles a ffect the thinning process behavior of the plane-parallel liquid film. In the case of vesicle from egg phosphatidylcholine (PC), the plane-p arallel foam film made of its suspension shows a gradual but inhomogen eous slow thinning process, which differs from the stepwise thinning p rocess of thin liquid films with silica or micelle suspensions reporte d in previous investigations. However, when lysophosphatidylcholine wa s mixed with egg PC, channel formation and coexistence of black thin f ilms and thicker regions were observed. (C) 1998 Academic Press.