Experimental results are presented on the study of photoinduced formation of droplets in thin layers of solutions and melts of certain molecular compounds. When a thin layer of melt or solution with open surface was irradiated in a tray, we observed stratification of the liquid, resulting in the formation of an isolated moving droplet, which is preceded by appearance of surface irregularities and break of the film due to local increase in the surface tension attendant to evaporation of the solvent. The droplet follows the light spot on the tray surface and is enriched by the less volatile component of the solution. The motion of the droplet is induced by movement of the wetting field in the field of the temperature gradient.
Faculty of Physics, Moscow State University, Leninskie Gory, Moscow, 119992, Russia