Immobilization of Xanthate Agent on Titanium Dioxide and Surface Initiated RAFT Polymerization

Surface modification of titanium dioxide (TiO₂) nanoparticle is essential to control its surface properties, thereby to enhance its cell penetration capability, reduce its cytotoxicity, or improve its biocompatibility. In order to graft polyvinyl acetate onto TiO₂ nanoparticles, xanthate was chemically immobilized on the surface of TiO₂ by acylation followed by nucleophilic substitution with a carbodithioate salt. Reversible addition fragmentation chain transfer polymerization was conducted to graft vinyl acetate onto the surface of TiO₂. Both the TiO₂-xanthate and TiO₂-polyvinyl acetate hybrids were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The chemical immobilization of xanthate on the surface of TiO₂ and the subsequent controlled polymerization provide useful insight for decoration and modification of TiO₂ and other nanoparticles.