Photocatalysed (Meth)acrylate Polymerization by (Antimony-Doped) Tin Oxide Nanoparticles and Photoconduction of Their Crosslinked Polymer Nanoparticle Composites

In the absence of another (photo)radical initiator Sb:SnO2nanoparticles ( 0≤Sb≤13 at %) photocatalyze during irradiation with UV light the radical polymerization of (meth)acrylate monomers. When cured hard and transparent (>98%) films with a low haze (<1%) are required, when these particles are grafted in advance with 3-methacryloxypropyltrimethoxysilane (MPS) and doped with Sb. Public knowledge about the photocatalytic properties of Sb:SnO2nanoparticles is hardly available. Therefore, the influence of particle concentration, surface groups, and Sb doping on the rate of C=C (meth)acrylate bond polymerization was determined with aid of real-time FT-IR spectroscopy. By using a wavelength of irradiation with a narrow bandgab ( 315±5 nm) the influence of these factors on the quantum yield (Φ) and on polymer and particle network structure formation was determined. It is shown that Sb doping and MPS grafting of the particles lowers Φ. MPS grafting of the particles also influences the structure of the polymer network formed. Without Sb doping of these particles unwanted, photocatalytic side reactions occur. It is also shown that cured MPS-Sb:SnO2/(meth)acrylate nanocomposites have photoconduction properties even when the particle concentration is as low as 1 vol.%. The results suggest that the Sb:SnO2( Sb>0 at %) nanoparticles can be attractive fillers for other photocatalytic applications photorefractive materials, optoelectronic devices and sensors.