Structural and Optical Characterizations of Polymethyl Methacrylate Films with the Incorporation of Ultrafine SiO(2)/TiO(2) Composites Utilized as Self-Cleaning Surfaces

The structural and optical characterizations of nanocomposite films of polymethyl methacrylate (PMMA) and SiO(2)/TiO(2) composites prepared via the spin-coating technique were investigated using different SiO(2):TiO(2) ratios. The SiO(2)/TiO(2) nanocomposites were synthesized using the sonochemical process with Si:Ti precursor ratios of 1:0.1, 1:0.5, 1:1, 1:2, 1:4, and 0:1. All characterizations of ultrafine SiO(2)/TiO(2) particles were loaded at 1 wt.% in a PMMA matrix for the fabrication of transparent SiO(2)/TiO(2)/PMMA composite films. The phase structure and morphology of SiO(2)/TiO(2)/PMMA composite films were monitored using X-ray diffraction, optical microscopy, and field-emission scanning electron microscopy. A surface roughness analysis of SiO(2)/TiO(2)/PMMA nanocomposite films was conducted using atomic force microscopy. For optical characterization, transmission properties with different incident angles of SiO(2)/TiO(2)/PMMA composite films were analyzed with UV-vis spectrophotometry. The water contact angles of SiO(2)/TiO(2)/PMMA composite films were analyzed to identify hydrophilic properties on film surfaces. Photocatalytic reactions in SiO(2)TiO(2) composite films under UV irradiation were evaluated using rhodamine B dye degradation. The optimal condition of SiO(2)/TiO(2)/PMMA nanocomposite films was obtained at a 1:1 SiO(2):TiO(2) ratio in self-cleaning applications, resulting from good particle dispersion and the presence of the TiO(2) phase in the composite.