The FDA first approved the use of titanium dioxide in food in 1966, following its 1960 removal (along with the removal of other color additives) from the agency's original Generally Recognized as Safe list. In 1977, titanium dioxide joined the list of color additives that are exempt from certification, which means titanium dioxide doesn't have to be listed on the packaging of every product it's used in, Faber noted.

In conclusion, calcium carbonate and titanium dioxide are important minerals that are used in various industries. While they are both produced by manufacturers, they have different manufacturing processes and applications. Understanding the differences between these two minerals can help industries make informed decisions about which one to use for their specific needs.

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.

For a review published in 2023 in the journal Environmental Pollution, researchers examined E171 as a possible factor promoting obesity-related metabolic disorders. Because gut microbiota play an important role in immune function maintenance and development, and because titanium dioxide as a food additive has been shown to alter gut microbiota, researchers wanted to review “the dysregulations along the gut microbiota-immune system axis after oral TiO2 exposure compared to those reported in obese or diabetic patients, and to highlight potential mechanisms by which foodborne TiO2 nanoparticles may increase the susceptibility to develop obesity-related metabolic disorders.” The study authors discovered recurrent changes in the gut microbiota composition when exposed to titanium dioxide nanoparticles, with an imbalance of intestinal symbiotic microbiota. These changes and imbalances were also reported and played a role in the development of obesity, the authors wrote. This highlights “foodborne TiO2 nanoparticles as an endocrine disruptor-like chemical promoting obesity-related disorders,” the authors concluded.

White crystalline powder. It is a mixture of zinc sulfide and barium sulfate. The more zinc sulfide it contains, the stronger the hiding power and the higher the quality. Density 4.136～4.34 g/cm3, insoluble in water. It easily decomposes when exposed to acid to produce hydrogen sulfide gas, but does not work when exposed to hydrogen sulfide and alkaline solutions. It turns into light gray after being exposed to ultraviolet rays in the sun for 6 to 7 hours, but it still returns to its original color when placed in a dark place. It is easy to oxidize in the air and will agglomerate and deteriorate when exposed to moisture.

Not lower 5%

The basic scenario of resistive switching in TiO₂ (Jameson et al., 2007) assumes the formation and electromigration of oxygen vacancies between the electrodes (Baiatu et al., 1990), so that the distribution of concomitant n-type conductivity (Janotti et al., 2010) across the volume can eventually be controlled by an external electric bias, as schematically shown in Figure 1B. Direct observations with transmission electron microscopy (TEM) revealed more complex electroforming processes in TiO₂ thin films. In one of the studies, a continuous Pt filament between the electrodes was observed in a planar Pt/TiO₂/Pt memristor (Jang et al., 2016). As illustrated in Figure 1C, the corresponding switching mechanism was suggested as the formation of a conductive nanofilament with a high concentration of ionized oxygen vacancies and correspondingly reduced Ti³⁺ ions. These ions induce detachment and migration of Pt atoms from the electrode via strong metal–support interactions (Tauster, 1987). Another TEM investigation of a conductive TiO₂ nanofilament revealed it to be a Magnéli phase Ti_nO_2n−1 (Kwon et al., 2010). Supposedly, its formation results from an increase in the concentrations of oxygen vacancies within a local nanoregion above their thermodynamically stable limit. This scenario is schematically shown in Figure 1D. Other hypothesized point defect mechanisms involve a contribution of cation and anion interstitials, although their behavior has been studied more in tantalum oxide (Wedig et al., 2015; Kumar et al., 2016). The plausible origins and mechanisms of memristive switching have been comprehensively reviewed in topical publications devoted to metal oxide memristors (Yang et al., 2008; Waser et al., 2009; Ielmini, 2016) as well as TiO₂ (Jeong et al., 2011; Szot et al., 2011; Acharyya et al., 2014). The resistive switching mechanisms in memristive materials are regularly revisited and updated in the themed review publications (Sun et al., 2019; Wang et al., 2020).