The use of sunscreens should also be recommended in order to work against all kind of ultarviolet (UV)-induced skin damage such as photoallergies, skin wrinkles, sunburn or even skin cancer. Sunscreens contain chemical filters (organic; absorb regularly UVB radiation) and physical filters (e.g., TiO2 and ZnO). The second group has been said to reflect and scatter UVB and UVA radiation. TiO2 is also extensively used in sunscreen formulations as active broadband sunscreens that blocks both UVB (290–320 nm) and UVA (320–400 nm). Although titanium dioxide is listed as a safe pigment, with no known adverse effects when it is used in cosmetics, but we should concern about ultrafine or nanoparticle form of titanium dioxide. If titanium dioxide particles used to act as a sunscreen are small enough, they can penetrate the cells, leading to photocatalysis within the cell, and cause DNA damage after exposure to sunlight.

Background and Objectives: Dye is considered as one of the most important environmental pollutants in industrial wastewater due to its harmful effects on both human and environment. This study was aimed to determine Optimum dioxide titanium Nanoparticles in dioxide titanium /Bentonite Composite for Sono-photocatalytic de-colorization of Methyl Orange dye. Methods: In this study, bentonite was used as the substrate to stabilize titanium dioxide photo-catalyst and the optimum amount of stabilized titanium dioxide nanoparticles in titanium dioxide/ bentonite composite which was evaluated for sono-photocatalytic removal of methyl orange dye. Accordingly, the optimal conditions for the photocatalytic process performance in dye removal included the effect of pH, methyl orange concentrations and nanocomposite doses. Findings: Structural properties of bentonite/titanium dioxide composites and pure titanium dioxide nanoparticles were investigated using scanning electron microscope (SEM), Diffuse Reflectance Spectroscopy (DRS) and X-ray diffraction (XRD). Finally, the possibility of reuse of photo-catalyst was investigated in three periods. Based on SEM results, reducing the amount of titanium dioxide reduced the number of nanoparticles formed on the bentonite surface. XRD and DRS analyses showed successful composite formation. The optimum amount of titanium dioxide nanoparticles in titanium dioxide/bentonite composite was obtained for sono-photocatalytic dye removal of methyl orange with the titanium dioxide powder to bentonite ratio of 1: 2. 5 in the primary mixture. Discussion and Conclusion: The study showed that increasing the amount of photo-catalyst in the reaction medium increased the speed and efficiency of the dye removal but its excessive increase had a negative effect on the reaction. The best conditions for dye degradation were obtained using titanium dioxide/bentonite nanocomposite at pH 4. According to the results, the increase in concentration increased dye removal time. Finally, the sono-photocatalytic composite efficiency was acceptable after three times of reuse.

Objective(s): Quince seed mucilage (QSM) serves as a new source of hydrocolloid which extracted from outer pericarp of Cydonia oblonga seeds upon wetting. It has been traditionally used for the treatment of diseases such as pharyngeal disorder, common cold, colic ulcer, and diarrhea. The aim of the present study was to evaluate the physico-mechanical and antimicrobial properties of quince seed mucilage supplemented with titanium dioxide (TiO2) and Silicon dioxide (SiO2) nanoparticles. Methods: The antimicrobial property of designated QSM against Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium, and Escherichia coli O157: H7 was determined using agar disk diffusion and broth micro-dilution assays. Thickness, tensile strength (TS), puncture force (PF), puncture deformation (PD), swelling index (SI), and color of active QSMs were evaluated using analytical instruments. Results: The films containing TiO2 and SiO2 nanoparticles exhibited good antimicrobial effects against S. aureus, B. subtilis, B. cereus, L. monocytogenes, S. typhimurium, and E. coli O157: H7 ranged 0. 82-6. 88 mm and-2. 78--0. 28 log differences in population (DP) regarding agar disk diffusion and broth microdilution assays, respectively. The presented values, including TS, PF, and PD of QSM films, were in the ranges of 22. 45-35. 81 MPa, 10. 42-15. 49 N, and 15. 53-18. 45 mm, respectively. Conclusions: Application of TiO2 and SiO2 nanoparticles greatly improved the antimicrobial and physico-mechanical properties of the prepared films.

Background and Objectives: Dye is considered as one of the most important environmental pollutants in industrial wastewater due to its harmful effects on both human and environment. This study was aimed to determine Optimum dioxide titanium Nanoparticles in dioxide titanium /Bentonite Composite for sono photo catalytic de-colorization of Methyl Orange dye. Methods: In this study, bentonite was used as the substrate to stabilize titanium dioxide photo catalyst and the optimum amount of stabilized titanium dioxide nanoparticles in titanium dioxide/ bentonite composite was evaluated for sono photo catalytic removal of methyl orange dye. Accordingly, the optimal conditions for the photo catalytic process performance in dye removal included the effect of pH, methyl orange concentrations and nanocomposite doses. Findings: Structural properties of bentonite/titanium dioxide composites and pure titanium dioxide nanoparticles were investigated using scanning electron microscope (SEM), Diffuse Reflectance Spectroscopy (DRS) and Xray diffraction (XRD). Finally, the possibility of reuse of photo catalyst was investigated in three periods. Based on SEM results, reducing the amount of titanium dioxide reduced the number of nanoparticles formed on the bentonite surface. XRD and DRS analyses showed successful composite formation. The optimum amount of titanium dioxide nanoparticles in titanium dioxide/bentonite composite was obtained for sono photo catalytic dye removal of methyl orange with the titanium dioxide powder to bentonite ratio of 1: 2. 5 in the primary mixture. Discussion and Conclusion: The study showed that increasing the amount of photo catalyst in the reaction medium increased the speed and efficiency of the dye removal but its excessive increase had a negative effect on the reaction. The best conditions for dye degradation were obtained using titanium dioxide/bentonite nanocomposite at pH 4. According to the results, the increase in concentration increased dye removal time. Finally, the sono photo catalytic composite efficiency was acceptable after three times of reuse.