In order to prepare hollow latex particles with optimum morphology based on osmotic swelling principle

three-layer core/shell latex particles with 40 wt% MAA in the core were first prepared

via

multistep seeded emulsion copolymerization

in which monomers were added by a semi-continuous process with monomer addition under two different forms: pure monomers’ mixture (monomer addition)

and pre-emulsified monomers (pre-emulsion addition). Then

the hollow latex particles with different morphologies were obtained after alkali post-treatment. Influences of the monomer feeding mode on the emulsion polymerization and the particle morphology were investigated. Results showed that the preemulsion addition could significantly improve the polymerization stability in each step

and greatly enhance the uniformity of shell encapsulation. The sizes of the core and core/shell latex particles obtained by the pre-emulsion addition were smaller and more uniform than those synthesized by the monomer addition

and the hollow latex particles with intact morphology were generated by alkali post-treating of the core/shell latexes prepared from the pre-emulsion addition. As the core size increased

the morphology of the post-treated particles underwent evolution from hollow to collapse. Moreover

the mechanism of the particle morphological evolution was proposed.