Although barium sulfate is almost completely inert, zinc sulfide degrades upon exposure to UV light, leading to darkening of the pigment. The severity of this UV reaction is dependent on a combination of two factors; how much zinc sulfide makes up the pigments formulation, and its total accumulated UV exposure. Depending on these factors Lithopone B301, Lithopone B311 powder itself may vary in shade over time, ranging from pure white all the way to grey or even black. To suppress this effect, a dopant might be used, like small amount of cobalt salts, which would be added to the formulation. This process creates cobalt-doped zinc sulfide. The cobalt salts help to stabilize zinc sulfide so it will not have as severe a reaction to UV exposure.
Infrared analysis showed that the characteristics bands for the bare nanoparticles are still exhibited in the vitamins@P25TiO2NPs spectra, such as a wide peak in 450–1028 cm−1 related to the stretching vibration of Ti-O-Ti and other peaks in 1630 cm−1 and 3400 cm−1, which represent the surface OH groups stretching. The IR spectrum of vitaminB2@P25TiO2NPs showed signs of binding between compounds. The OH bending peak (1634 cm−1) corresponding to bare nanoparticles disappeared, and the NH2 bending band characteristic of vitamin B2 appeared (1650 cm−1). The IR spectrum of vitaminC@P25TiO2NPs also showed signs of successful functionalization. Bands at 1075 cm−1; 1120 cm−1; 1141 cm−1 were observed, which are originated by C
O-C vibrations present in the vitamin C. The intense band at 1672 cm−1 is attributed to the C = O stretching in the lactone ring while the peak at 1026 cm−1 is ascribed to the stretching vibration Ti-O-C. Wide bands at 3880–3600 cm−1 are related to stretching vibration OH groups, but those disappear in the modified nanoparticles spectrum. These observations confirm the interactions between the P25TiO2NPs and the vitamins [35].
Used for coloring paint, ink, rubber, etc. Inorganic white pigments are widely used as white pigments in plastics such as polyolefin, vinyl resin, ABS resin, polystyrene, polycarbonate, nylon and polyformaldehyde, as well as paints and inks. It is less effective in polyurethane and amino resins, and less suitable in fluoroplastics. It is also used for coloring rubber products, papermaking, varnished cloth, oilcloth, leather, watercolor paints, paper, enamel, etc. Used as an adhesive in the production of electric beads.
Titanium is one of the most common metals on earth, but it does not occur naturally in this elemental form. TiO2, also known as titanium (IV) oxide or titania, is the naturally occurring compound created when titanium reacts with the oxygen in the air. As an oxide, titanium is found in minerals in the earth’s crust. It is also found with other elements, including calcium and iron.
The aim of this work was to examine particularly the Degussa P25 titanium dioxide nanoparticles (P25TiO2NPs) because they are among the most employed ones in cosmetics. In fact, all kinds of titanium dioxide nanoparticles (TiO2NPs) have gained widespread commercialization over recent decades. This white pigment (TiO2NPs) is used in a broad range of applications, including food, personal care products (toothpaste, lotions, sunscreens, face creams), drugs, plastics, ceramics, and paints. The original source is abundant in Earth as a chemically inert amphoteric oxide, which is thermally stable, corrosion-resistant, and water-insoluble. This oxide is found in three different forms: rutile (the most stable and substantial form), brookite (rhombohedral), and anatase (tetragonal as rutile), of these, both rutile and anatase are of significant commercial importance in a wide range of applications [3]. Additionally, the nano-sized oxide exhibits interesting physical properties, one of them is the ability to act as semiconducting material under UV exposure. In fact, TiO2NPs are the most well-known and useful photocatalytic material, because of their relatively low price and photo-stability [4]. Although, this photoactivity could also cause undesired molecular damage in biological tissues and needs to be urgently assessed, due to their worldwide use. However, not all nanosized titanium dioxide have the same behavior. In 2007, Rampaul A and Parkin I questioned: “whether the anatase/rutile crystal form of titanium dioxide with an organosilane or dimethicone coat, a common titania type identified in sunscreens, is appropriate to use in sunscreen lotions” [5]. They also suggested that with further study, other types of functionalized titanium dioxide could potentially be safer alternatives. Later, Damiani found that the anatase form of TiO2NPs was the more photoactive one, and stated that it should be avoided for sunscreen formulations, in agreement with Barker and Branch (2008) [6,7].
A 2023 study published in the journal Particle and Fibre Toxicology set out to examine the impact of titanium dioxide nanoparticles in mice “on the course and prognosis of ulcerative colitis,” by creating an ulcerative colitis disease model. Researchers found that the titanium dioxide nanoparticles significantly increased the severity of colitis. They also “decreased the body weight, increased the disease activity index and colonic mucosa damage index scores, shortened the colonic length, increased the inflammatory infiltration in the colon.” Researchers concluded: “Oral intake of TiO2 nanoparticles could affect the course of acute colitis in exacerbating the development of ulcerative colitis, prolonging the ulcerative colitis course and inhibiting ulcerative colitis recovery.”
Titanium dioxide exists primarily in three crystalline forms rutile, anatase, and brookite. Among these, anatase is characterized by its unique electronic properties and higher photocatalytic activity, making it suitable for applications requiring enhanced light absorption and reactivity. Its ability to act as a photocatalyst enables the breakdown of organic pollutants, making it a valuable component in environmental remediation strategies.
Still, in 2016 Skittles publicly declared it would get rid of the chemical compound in its products, according to a press release at the time from the Center for Food Safety, which called the substance harmful and potentially poisonous. But the ingredient remains, according to the lawsuit, which alleges the candy company is misleading consumers by not having eliminated titanium dioxide.
The journey of TIO2 begins with mining raw materials, primarily ilmenite, rutile, and anatase minerals, which are then processed through various methods including the chloride process or the sulfate process. The chosen procedure significantly impacts the final characteristics of the TIO2 pigment, such as its particle size, distribution, and crystalline structure, which in turn affect its optical properties. 
Its high refractive index allows it to scatter light effectively, resulting in brighter colors and improved opacity Its high refractive index allows it to scatter light effectively, resulting in brighter colors and improved opacity