Abstract: The film formation process of micro-PSparticles (diameter 742 nm) and nano-PSparticles (diameter 29 nm) was studied by means of AFMand DSC. During a step heating process, the particles were annealed for 0. 5 h at each selected temperature. It is found that the deformation and interdiffusion temperatures are ca. 393-403 Kand 413-423 Kfor the micro-PSparticles, 363 Kand 373-383 Kfor the nano-PSparticles respectively. Comparing to the micro-PS particles, the sintering process of nano-PS particles occurs at much lower temperature determined by the confined state of polymer chains with less interactions between segments, leading to a higher conformational energy, and completed in much narrower temperature range driven mainly by the larger total surface energy.

Key words: Polystyrene latex, Filming process, Particle size effect