OBSERVATIONS OF LATEX PARTICLE 2-DIMENSIONAL-CRYSTAL NUCLEATION IN WETTING FILMS ON MERCURY, GLASS, AND MICA

We studied the nucleation of two-dimensional crystals from micrometer- and submicrometer-size latex particles in liquid films formed on merc ury, glass, and mica. For the experiments on mercury we controlled bot h the film thickness and the mercury surface electric potential, where as for the experiments on glass and mica we traced the film thickness as a function of time. The nucleation of monolayers from micrometer-si ze particles was obtained on mercury only in a narrow interval of low positive electric potentials applied to the mercury. Both the micromet er and the submicrometer particles started to assemble when the film t hickness became equal to the particle diameter. Our results suggest th at the lateral capillary immersion forces, which appeared between the particles protruding from the liquid film, arranged these particles in a two-dimensional-crystal nucleus.