Fig. 2. SEM micrograph and EDS map of the same area of a vitaminB2@P25TiO2NPs.
Barium sulphate, a chemical compound with the formula BaSO₄, is widely recognized for its numerous applications in various industries, particularly in the field of medicine, paints, plastics, and as a component in drilling fluids. One of the distinguishing features of barium sulphate is its striking physical property its color. Understanding the color of barium sulphate not only helps in identifying the compound during handling but also plays a significant role in its applications and quality assessment.
Below 20% substitution, it is recommended to replace 1 kg of TiO2 with 1 kg of Lithopone.
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.