ironing board under cover_bandana tablecloth

Now imagine the delicate skin on your face, on your children’s arms & legs. Each day un-knowingly, thinking we are doing the right thing, we slather them up with titanium dioxide in the form of sunscreen & send them out into the sun, all the while never knowing that once exposed to light titanium dioxide creates free radicals that are strong enough to damage steel roofing panels!!

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.

The precipitation of titanium dioxide is a crucial process in the manufacturing of this important industrial material. Titanium dioxide is a white pigment that is widely used in various industries, such as paints, coatings, plastics, and cosmetics, due to its excellent opacity, brightness, and UV resistance.

Dr Peter  Dingle (BEd, BSc, PhD)