POSS/TiO₂ Nanohybrids as Sun Protection Factors for Skin Changes Caused by Ultraviolet A Radiation

Abstract

Based on (3-methacryloxypropyl)-Polyhedral oligomeric silsesquioxane (MP-POSS) (MP), vinyl-POSS (VP), (3-glycidoxypropyl)-POSS (GP) and modified with 5, 10, 15, 20 and 25 wt-% titanium tetrabutoxide (TTB), three hybrid nanofilms (f-MPT, f-VPT and f-GPT) were prepared using hydrolytic condensation and crosslinking. The transparency of the films was measured at the ranges of ultraviolet A (UV-A) (320-400 nm) spectrum which can cause a much greater risk of skin changes. The average transparency (AT) values of three films were about 65-78% (320-350 nm) and 85-89% (350-400 nm), which implies that these films indeed can provide a physical barrier for blocking the UV-A absorbed into the skin, indicating functionality of the POSS/TiO2 materials as the sun protection factor (SPF) ingredients in a sunscreen. The AT values of three films were in the order of f-MPT>f-GPT>f-VPT due to complete-cage structures of building blocks (POSS) and the size of organic branches covalently bonded to the silica network in the molecular structures. This indicates that VPT powder might be significantly better to selected for the SPF. The TTB addition results in the hybrid structure containing TiO2 which causes a decrease in the AA radiation from sunlight. Lower transparency of the films containing 25 wt-% TTB fractions is ascribed to more amounts of TTB in the modified films.

Modified Vinyl–POSS Materials as Sun Protection Factor and as Films for Greenhouse Cover

“…Lower AT of the films containing 30 wt-% TEOS fractions is ascribed to more amounts of TEOS in the modified films [18]. Although the TEOS addition results in the hybrid structure containing SiO 2 making the higher AT value (lower than TiO 2 [19]), it can cause this ingredient stable in SPF and mosquito insecticides, which is an applicable for military in the desert. Therefore, for a special application, more TEOS fractions should be added to enhance SPF functionality.…”

Transparency of modified vinyl-silsesquioxane films and its validation by computing energy-band structure

“…2(a), the average AT values of f-VSTE in the VIS and NIR regions are 92.06% and 90.72%, respectively, showing higher transparency values than those of the neat VERSUS film (91.62% and 90.50%). 23 Fig. Both the VIS and NIR light regions give crop growth energy, and the best growth rate is obtained through a combination of energy and spectral distribution.…”

<i>In Situ</i> Formation of Insect Repellent Delivery System

“…One of the important advantages of these silsesquioxane nanostructured hybrids is that they are toolarge to have appreciable vapor pressures and hence do not add to air pollution as a volatile organic vapor [3]. Another important advantage of silsesquioxane hybrids is that they can have a high sun protection factor (SPF) for protection from UV radiation and the prevention of skin damage [4]. As mentioned above, silsesquioxane area good candidate as chemical delivery system to provide constant and longer protection against insect vectors of diseases and simultaneously prevent UV radiation skin damageundersevere environmental conditions.…”