Extruded expanded polystyrene sheets coated by TiO2 as new photocatalytic materials for foodstuffs packaging

Abstract Nanostructured, photoactive anatase TiO 2 sol prepared under very mild conditions using titanium tetraisopropoxide as the precursor is used to functionalise extruded expanded polystyrene (XPS) sheets by spray-coating resulting in stable and active materials functionalised by TiO 2 nanoparticles. Photocatalytic tests of these sheets performed in a batch reactor in gas–solid system under UV irradiation show their successful activity in degrading probe molecules (2-propanol, trimethylamine and ethene). Raman spectra ensure the deposition of TiO 2 as crystalline anatase phase on the polymer surface. The presence of TiO 2 with respect to polymer surface can be observed in SEM images coupled to EDAX mapping allowing to monitor the surface morphology and the distribution of TiO 2 particles. Finally thermoforming of these sheets in industrial standard equipment leads to useful containers for foodstuffs.