ANNEALING EFFECTS ON THE SURFACE-STRUCTURE OF LATEX FILMS STUDIED BY ATOMIC FORCE MICROSCOPY

The effect of annealing on latex film surface structure was followed b y atomic force microscopy. The films were prepared from poly(butyl met hacrylate) particles (PBMA, d = 337 nm) prepared by surfactant-free em ulsion polymerization. The film surfaces were highly ordered, consiste nt with face-centered cubic packing in the film interior, and each par ticle maintained a truncated spherical shape. The peak-to-valley dista nce DELTAz was monitored as a function of annealing time. From DELTAz, the remaining surface per particle was calculated. With the aid of a simple diffusion model, we conclude from these data that polymer chain s near the latex surface diffuse much faster than those within the fil m.