kowet titanium dioxide manufacturers

Résumé–Cet article traite de la découverte de lithopone phosphorescent sur des dessins à l'aquarelle, datés entre 1890 et 1905, de l'artiste Américain John La Farge et de l'histoire du lithopone dans l'industrie des pigments à la fin du 19e et au début du 20e siècle. Malgré de nombreuses qualités souhaitables pour une utilisation en tant que blanc dans les aquarelles et les peintures à l'huile, le développement du lithopone comme pigment pour artistes a été compliqué de par sa tendance à noircir lorsqu'il est exposé au soleil. Sa disponibilité et son usage par les artistes demeurent incertains parce que les catalogues des marchands de couleurs n'étaient généralement pas explicites à indiquer si les pigments blancs contenaient du lithopone. De plus, lors d'un examen visuel, le lithopone peut être confondu avec le blanc de plomb et sa phosphorescence de courte durée peut facilement être ignorée par l'observateur non averti. À ce jour, le lithopone phosphorescent a seulement été documenté sur une autre œuvre: une aquarelle de Van Gogh. En plus de l'histoire de la fabrication du lithopone, cet article décrit le mécanisme de sa phosphorescence et son identification à l'aide de la spectroscopie Raman et de la spectrofluorimétrie.

...

The manufacturing process of titanium dioxide typically involves mining ilmenite, rutile, or anatase from natural sources, followed by conversion into TiO2 through various chemical processes. The resulting TiO2 can then be further processed to achieve different particle sizes and coatings that optimize its performance in specific applications. For instance, TiO2 used in sunscreens is often coated to enhance its effectiveness in blocking UV rays without causing skin irritation.

...

The vitaminC@P25TiO2NPs, on the other side, did not have any effect on cell protection against ROS. This might be due to the fact that vitamin C, a well-known scavenger of ROS, could behave as prooxidant and even promote ROS and lipid peroxidation [39]. It was recently described that at small concentrations of vitamin C, the prooxidant effects dominate; while in large concentrations the antioxidant ones predominate [40]. The effect also depends on the cell state and the interaction of vitamin C with light. In this case, ascorbic acid may act as an antenna to harvest visible light when conjugated to P25TiO2NPs. Indeed, it was previously found that this combination (in some ratios) could have an improved photocatalytic activity, possibly due to a red shift in its light absorbance [41]. Further studies on vitaminC@P25TiO2NPs were not conducted, because of the poor antioxidant capacity [42].

...


Why all of a sudden is there so much interest in the safety of Titanium Dioxide?

Researchers from France and Luxembourg gave E171 (the much more food friendly name for Titanium Dioxide) in Europe and the United States, to lab rats in their drinking water for 100 days.

Of those rats, 40 per cent of the exposed rodents developed “preneoplastic lesions” or precancerous growths. The Titanium Dioxide also inhibited the immune systems of the rats and “accelerated” the growth of the lesions. France’s INRA agricultural research institute, which took part in the study, said in a statement.“These results demonstrate a role in initiating and promoting the early stages of colorectal cancer formation,” though it said no conclusion could be drawn about later phases of cancer, or of any danger to humans……….(not till they test it on us!!)

The results of the study were published in the Nature journal Scientific Reports.

...
{随机栏目} 2025-08-14 06:18 1308
  • It offers several advantages in various applications. Its excellent opacity and brightness make it a popular choice in the production of paints, coatings, and printing inks, providing a cost-effective alternative to titanium dioxide. Lithopone's chemical stability enhances its durability in outdoor environments, making it suitable for outdoor coatings. Additionally, its low reactivity and compatibility with other pigments contribute to its versatility. Beyond coatings, lithopone finds utility in plastics, rubber, and paper industries. Overall, its multifaceted advantages and broad applications underscore this compound's significance in diverse industrial sectors.

    {随机栏目} 2025-08-14 04:01 2978