PATTERN FORMATIONS IN LIPID MONOLAYERS UNDER ILLUMINATION

In Lipid monolayer film we observed that the domains of the liquid-con densed phase may grow under continuous illumination of microscope ligh t. This phenomenon occurred in the coexistence region of liquid-conden sed (LC) and liquid-expanded phases. The average area per molecule in the monolayer film remained constant during the domain growth. By anal yaing the growth behaviors of the LC domains carefully, we found that the observed domain growth arises from an illumination-related local m ass transfer, which can be attributed to the light-induced damage to t he fluorescence molecules; our previous explanations [Wang et al., Phy s. Rev. Lett. 71, 4003 (1993)] should be modified. Our results demonst rate the significant effect of the decomposed fluorescence molecules o n the growth of the domains in the liquid-condensed phase. This effect may also be used to study the domain growth dynamics.