Synthesis of conductive PSt-g-PANi/TiO2 nanocomposites by metal catalyzed and chemical oxidative polymerization

Abstract

Well-defined polymer-TiO2 nanocomposites of core–shell structure were prepared by two-steps, surface-initiated atom transfer radical polymerization (ATRP) of styrene and in situ chemical oxidative polymerization of aniline monomers from the surfaces of the TiO2 nanoparticles. The methods used include the following: initially, the ATRP initiator was covalently attached to the surface of TiO2 nanoparticles by esterification of 2-bromo-2-methyl propionic acid with hydroxyl group. The metal-catalyzed radical polymerization of styrene with modified TiO2 nanoparticles was performed using a copper catalyst system to give the TiO2-based core hybrids linking PSt segments (TiO2-PSt hybrids). Next, the TiO2-PSt reacted with HNO3/H2SO4 to produce a nitro group containing polystyrene to form TiO2-PSt-NO2, and obtained TiO2-PSt-NO2 was treated with hydrochloric acid/SnCl2, and converted to an amine group containing polystyrene (TiO2–PSt-NH2). Finally, surface oxidative graft copolymerization of aniline, using the –NH2 moieties of TiO2/PSt-NH2 as the anchoring sites. Characterization of these well-defined nanocomposites included FTIR, thermogravimetric analysis, transmission electron microscopy, and X-ray diffraction.