pigment lithopone quotes
Titanium dioxide can form several different shapes, which have different properties. Some shapes can be converted to nanomaterials. Micronized TiO2 (also called “nano” or “nanoparticles”) was introduced in the early 1990s. Nanotechnology and micronization both refer to the practice of creating very small particles sizes of a given material. “Nanoparticles” usually refers to particles smaller than 100 nanometers; a nanometer is 1/1 billionth of a meter. At these small sizes, and at low concentrations, titanium dioxide appears transparent, allowing for effective sunscreens that do not appear white.
The conjugation of vitamin C to the P25TiO2NPs was confirmed by UV-visible spectroscopy of lyophilized vitaminC@P25TiO2NPs suspensions. The typical absorbance peak of ascorbic acid at 265 nm was found. However, no further characterization was done because they did not show the expected protective effect against the photo-induced cell damage (Fig. 3).
