Photocatalytic polymerization induced by a transparent anatase titania aqueous sol and fabrication of polymer composites

Abstract

Abstract. The surface modification of the anatase titania nanoparticles prepared via a controlled nonhydrolytic sol-gel process is achieved by the formation of the bidentate coordination between titania and methacrylic acid (MAA) molecules. The in situ photocatalytic polymerization of methyl methacrylate (MMA) monomer is initiated by surface modified anatase titania nanoparticles under Xe lamp irradiation. A variety of techniques including differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and scanning electron microscopy (SEM) are employed to characterize the resulting materials. The glass transition temperatures and the thermal stabilities of polymethyl methacrylate (PMMA) composite materials prepared via photocatalytic polymerization are enhanced compared with pure polymer. The partial aggregation of titania nanoparticles in PMMA composite films is derived from the surface polymerization of MMA, which makes the inorganic particles hydrophobic and drives them to the water/oil interfaces.

Nanocomposite fabrication via direct ultra-fast laser ablation of titanium in aqueous monomer solution

“…As was shown in earlier studies, the polymerization of various monomers can be a direct consequence of the photoabsorption of TiO 2 nanoparticles, which act as photoinitiators for the polymerization [17][18][19]21]. TiO 2 is a photosensitive, wide bang gap semiconductor of ~3.0 eV.…”

“…The use of UV light in the fabrication process of nanocomposites is considered a sustainable alternative that can minimize the use and waste of chemicals. UV light irradiation of monomer solutions incorporating nanoparticles with photocatalytic properties, like ZnO and TiO 2 , has already been used to initiate polymerization due to photoexcited species that are generated upon photoirradiation [16][17][18][19][20][21][22]. However, in these cases the nanoparticles are synthesized in separate steps that involve chemical routes, and are later added to the polymer solutions.…”

On the morphology and potential application of polydimethylsiloxane-silica-titania composites

“…Other components can be added as well to achieve the desired properties. Thus, ferric oxide, titanium dioxide and organometallic compounds are added as heat stabilizers or pigments [7]. Titanium dioxide is one of the most important fillers used for obtaining composites designed for engineering applications [8].…”