Poly(2-hydroxyethylmethacrylate)-silica mesoporous composite(MCM-41-g-PHEMA)was successfully synthesized by precipitation polymerization in supercritical carbon dioxide with 2-hydroxyethyl methacrylate(HEMA)as monomer,vinyl triethoxy silane modified the mesoporous molecular sieve MCM-41 as carrier,azoisobutyronitrile as initiator.The effects of reactant ratio,reaction time and pressure on the morphology and yield of the complexes were investigated.The synthesized composites were characterized through FTIR,B...