Development of dapsone-capped TiO2 hybrid nanocomposites and their effects on the UV radiation, mechanical, thermal properties and antibacterial activity of PVA bionanocomposites

In the present work, dapsone-capped TiO2 nanoparticles (DAP-TiO2-NPs) were successfully prepared as a decorated bio-agent for enhancing the properties of the biodegradable polyvinyl alcohol (PVA) nanocomposites. The structure of synthesized TiO2-NPs was characterized by X-ray diffraction (XRD). The fabricated biodegradable films were subjected to variable tests like SEM analysis, UV–vis spectroscopy, mechanical properties, thermogravimetric analysis (TGA), as well as antibacterial activity. The SEM images showed that the capping dapsone into the surface of TiO2-NPs improved the dispersion degree and miscibility of DAP inside the PVA matrix, especially at 0.1 % filler content. The obtained results from UV–vis exhibited that all fabricated films based on DAP-TiO2-NPs possessed superb UV-shielding properties even at lower nanofiller ratios, blocking nearly all three bands of UV lights, and up 98 % of visible light as well, irrespective to neat PVA or PVA/DAP blend. Withal, UV–vis reflectance was revealed that the reflectivity of filled films was changed in the visible range with increasing UV exposure time, indicating the color change in the film within a few minutes. These data were confirmed by chromaticity co-ordinates calculations. Also, the tensile properties, thermal stability, and antibacterial activity of nanocomposite films were remarkably improved. This study points out that a new utilization for PVA/DAP-TiO2 nanocomposite films in promising applications such as food-safe packaging and UV-blocking biomedical areas.