Lithopone, C.I. Pigment White 5, is a mixture of inorganic compounds, widely used as a white pigment powder. It is composed of a mixture of barium sulfate and zinc sulfide. These insoluble compounds blend well with organic compounds and confer opacity. It was made popular by the cheap production costs, greater coverage. Related white pigments include titanium dioxide, zinc oxide (zinc white), zinc sulfide, and white lead.
The company has a wide variety of products, mainly including rutile titanium dioxide R818, R838, R868, R878, covering profiles, also have anatase TiO2 A1. Soft plastics and masterbatches, flat coatings, high-gloss coatings, water-based coatings, oil-based coatings, rubber, powder coatings, papermaking and other special fields, its products have been known in the market for their excellent whiteness and brightness, good hiding power and tinting power, stable application performance, and stable product quality and supply capacity.
In order to contribute with experimental evidence that could help to achieve a better understanding of the field for future regulation, in the present work, the biocompatibility of commercial P25TiO2NPs (one type of TiO2NPs used in sunscreen formulations) and two novel functionalized P25TiO2NPs were evaluated under solar simulated irradiation. White light, generated by red, blue, and yellow LEDs, together with UV ones, was chosen to simulate the solar spectra. Functionalization of TiO2NPs was made with antioxidant vitamins in order to prevent the expected photo-initiated ROS production when nanoparticles are exposed to the simulated solar spectra. Vitamin B2 (riboflavin) and vitamin C were chosen to carry out the functionalization because they are water-soluble, low-cost, and are a constitutive part of biological processes. In addition, it is known that both have the potential to prevent macromolecular oxidation by ROS [23], [24], [25], [26].