Fumed silica/polymer hybrid nanoparticles prepared by redox-initiated graft polymerization in emulsions

摘要: Hybrid particles comprising aggregated fumed silica nanoparticles as the core and hydrophobic polymers existing around were prepared by ‘grafting from’ polymerization in emulsions. The emulsion employed cetyltrimethylammonium bromide (CTAB) a cationic surfactant sodium dodecyl sulfate (SDS) an anionic surfactant, respectively, to stabilize polymerization. was initiated redox reaction between ceric ion Ce(IV) amine groups on surfaces of aminated that modified 3-aminopropyltriethoxysilane. Infrared spectroscopy thermogravimetric analysis demonstrated both poly(methyl methacrylate) (PMMA) polystyrene (PS) successfully grafted onto surface. type greatly affected grafting ratio, monomer-to-polymer conversion, morphology product. When CTAB used ratio conversion lower than when SDS used, but transmission electron microscopy light scattering indicated most resultant sub-100 nm hybrid with non-spherical shape sizes 75–90 57–85 nm for PMMA PS-grafted silica, respectively. Whereas, agglomerated form large irregular clusters or even networks, possibly due electrostatic attractions and/or aqueous solution.