A method of forming, by polymerization in an aqueous dispersion at pressures
in
excess of one atmosphere, a plurality of porous particles having at least one polymeric
phase and at least one pore filling phase, wherein the pore filling phase includes
a pore filler and a fugitive substance, is disclosed. Replacement of the fugitive
substance with a replacement gas is further disclosed. Porous particles having
a polymeric phase and pores containing a pore filler, and, optionally, a gaseous
phase are also disclosed, as are their aqueous dispersions.
