ORDERING AND ADHESION OF LATEX-PARTICLES MODEL INORGANIC SURFACES

The ordering and adhesion of latex particles on model inorganic surfac e are. investigated through atomic force microscopy. The particles are made of a soft polymeric core protected by a hydrophilic membrane mad e of carboxylic acids, and they are dispersed in water. This dispersio n is:spread on model inorganic surfaces. After water evaporation, ther e is a monolayer of rather well dispersed particles on the substrate. The measured particle heights are dependent on the scanning rate and o n the force of the probe tip acting on the sample. Below the polymer g lass temperature, the particles have weak adhesion to the surface and are moved easily by the probe tip. This results in tip-induced organiz ation of the particles. The analysis of particle profiles shows that, above glass temperature, there is a sudden and partial spreading of th e particles which Is governed by the polymeric chain mobility and not by capillary forces. The particle adhesion and spreading ratio are con trolled by acid-base interactions between latex particles and the surf ace.