Synthesis of SiO2/PS composite particles via emulsion polymerization

SiO2 particles prepared by Stober method were modified using 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (Vi-D-4), and SiO2/polystyrene (PS) composite particles with core-shell structure were synthesized adopting mulsion polymerization of PS in a water-ethanol medium. The products were characterized by infrared spectra, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and Zetasizer analyzer. The average diameter of SiO2 particles prepared by Stober method was about 80 nm, the SiO2 particles were modified using the molar ratio of Vi-D-4 and SiO2 particles 1 : 10 (the dosage of Vi-D-4 benever too much), and the size of modified silica particles was about 90 nm. The infrared spectra indicated that the Vi-D-4 had bonded to the silanol groups on sur-face of SiO2 particles, and XPS indicated the grafting efficiency of Vi-D-4 on surface of SiO2 particles had reached 90%. The infrared spectra indicated the PS had been incorporated with SiO2 particles, and TEM indicated the composite particles have obvious core-shell structure. The suitable size of SiO2 particles should be lower than 200 nm, and the optimum volume ratio of ethanol and water should be 1 : 9 or 1 : 4. A kind of monodisperse SiO2/PS composite particles having function of self-assembling was successfully and effectively synthesized. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 43-49, 2011