extruded window screen frame

Lithopone is a mixed zinc sulfide-barium sulfate brilliant white pigment that contains about 30% zinc sulfide. The original light sensitiveness of this pigment has been mitigated by purification and by the addition of such agents as polythionates and cobalt sulfate.

In terms of refractive index and opacity, lithopone surpasses zinc oxide and lead oxide. Lithopone's high refractive index allows it to efficiently scatter and reflect light, thereby increasing the opacity of various media. Whether you need to enhance the opacity of paints, inks or plastics, lithopones deliver outstanding results, ensuring your final product is completely opaque.

Separately, concerns have been raised about titanium dioxide impacting one's genetic code. This can be traced to a 2009 study which found that titanium dioxide nanoparticles caused DNA damage and genetic instability in mice. A 2022 study published in Food and Chemical Toxicology also raised concerns about the DNA-damaging effects of titanium dioxide as a food additive. The study noted that results evidenced a DNA-damaging effect, and added that there may also be impacts to chromosomal integrity, an indicator of cancer risk.

Tint reducing power, compared with standard samples

While the FDA maintains that the regulated use of titanium dioxide is safe, the European Food Safety Authority and some other experts warn of potential, serious health risks.

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].

Because of its unique pigment and fine-milled texture, titanium dioxide has become popular over the past century in a wide variety of different products. These include adhesives, paints, plastics, rubbers, textiles, inks, ceramics, and even some pharmaceuticals, foods, and hygiene products.

This article discusses the discovery of phosphorescent lithopone on watercolor drawings by American artist John La Farge dated between 1890 and 1905 and the history of lithopone in the pigment industry in the late 19th and early 20th centuries. Despite having many desirable qualities for use in white watercolor or oil paints, the development of lithopone as an artists' pigment was hampered by its tendency to darken in sunlight. Its availability to, and adoption by, artists remain unclear, as colormen's trade catalogs were generally not explicit in describing white pigments as containing lithopone. Further, lithopone may be mistaken for lead white during visual examination and its short-lived phosphorescence can be easily missed by the uninformed observer. Phosphorescent lithopone has been documented on only one other work-to-date: a watercolor by Van Gogh. In addition to the history of lithopone's manufacture, the article details the mechanism for its phosphorescence and its identification aided by Raman spectroscopy and spectrofluorimetry.

In order to evaluate the penetration of the nanoparticles, eight adult male Wistar rats (3 months old) were used for the in vivo experiments. The protocol was approved by the local University Committee for animal testing and is in accordance with the Canadian Council on Animal Care (CICUAL-RD-2021–892-E-UNC-DEC#FCQ).