Abstract: In this study, carboxyl-functionalized polystyrene nanocapsules were synthesized using miniemulsion copolymerization. Both hexadecane (HD) and methyl isobutyl ketone (MIBK) were used as costabilizer for miniemulsion process. Effects of kinds and amount of the costabilizer on the morphology of end products were studied. It was found that substantial polymer particles has void core structure were formed and the diameter of particles was about 100nm when the weight ratio of monomer to costabilizer of 1:1. Oil-soluble dyes could be encapsulated into nanocapsules prepared using MIBK as costabilizer and UV irradiation experiments tests indicated that the obtained Polymer/dye latexes exhibited excellent photostability. However, dye molecules could not be encapsulated successfully when HD was employed as costablizer.

Key words: miniemulsion polymerization , surface functionalization , nanocapsule , nanocolorant