Supercritical fluid mediated synthesis of poly(2-hydroxyethyl methacrylate)/Fe3O4 hybrid nanocomposite

Poly(2-hydroxyethyl methacrylate) (PHEMA) and magnetic nanoparticle (Fe3O4) hybrid nanocomposite was synthesized by dispersion polymerization in supercritical carbon dioxide (scCO2) using a copolymeric stabilizer, poly[(2-dimethylamino)ethyl methacrylate-co-1H,1H-perfluorooctyl methacrylate] (PDMAEMA-co-PFOMA). Fe3O4 nanoparticles were first surface-modified with a silane coupling agent methacryloxypropyltrimethoxysilane (MPTMS), which provides a reactive CC bond and can copolymerize with 2-hydroxyethyl methacrylate (HEMA). After immobilization of the silane coupling agent, polymer chains were successfully grafted onto the surface of Fe3O4, resulting in the formation of core–shell nanostructure. FE-TEM pictures showed that the nanoparticles were well dispersed in the polymer matrix. The incorporation of Fe3O4 in the nanocomposite was confirmed by FT-IR, XRD and XPS. Thermal stability and magnetic property increase with the increasing amount of Fe3O4 nanoparticles in the composite. This new environmentally benign green synthetic route may offer advantages of easy separation and solvent removal.