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

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