FORMATION AND MORPHOLOGY OF LATEX MONOLAYERS - COMPUTER-SIMULATION STUDIES

The results of computer simulations of monolayers created from monodis perse latex particles are presented and discussed. Layers are characte rized by the normalized coverage, NC (the actual coverage of the surfa ce related to its maximum possible coverage with particles), and by th e average number of neighbors, ANN. calculated as the number of partic les being in contact with a given one and averaged over all the partic les on the surface. Variable parameters used in simulations include: t he rate of particles deposition, the probability of lateral movements, the probability of desorption of particles adsorbed on the surface, t he probability of covalent immobilization of adsorbed particles, and t he ''on-sphere slip'' parameter, OSS (characterizing the scattering of a falling particle on the particles being already attached to the sur face). Morphology of monolayers is qualitatively characterized by rela tions between ANN and NC. It is shown that for all monolayers formed w ithout adhesion (and without repulsion) between the particles adsorbed on the surface the dependence of ANN vs. NC is described by a charact eristic master curve (regardless of the values of probabilities of des orption and lateral movements of particles). For the monolayers create d including adhesive forces between the adsorbed particles the plots o f ANN vs. NC lie above the master curve, while similar plots obtained for the layers made of particles showing various types of repulsive in teractions are always placed below it. Thus, the dependencies of ANN v s. NC, derived from computer simulations, can be used for the determin ation of the character of the interparticle interactions in the real s ystems.