Titanium dioxide core/polymer shell hybrid composite particles prepared by two-step dispersion polymerization

Titanium dioxide inorganic core and polymer shell composite poly(styrene-co-divinylbenzene)-methacrylic acid (P[St-co-DVB)-MAA]) particles were prepared by two-step dispersion polymerization. Fourier transform IR (FT-IR) spectroscopy and elemental analysis were used to measure the content of methacrylic acid in composites particles. X-ray measurement photoelectron spectroscopy (XPS) measurements indicated the presence of an methacrylic acid (MAA) unit on the surface of the composite particles. The combined results of the elemental analysis and the XPS measurements showed that the copolymer on the surface of P[(St-co-DVB)-MAA] composite particles was rich in MAA compared with that in the interior of the composite particles. Field emission scanning electron microscopy (FE-SEM) was used to study the morphology characterization. TGA results indicated that the encapsulation efficiency and estimated density of composite particles. Encapsulation efficiency was up to 87.4% and the density was ranged from 1.78 to 2.06 g/cm(3). Estimated density of the composite particles was suitable to 1.73 g/cm(3), due to density matching with suspending media. (C) 2004 Elsevier B.V. All rights reserved.