TITLE: papermaking: Preparation of stock
SECTION: Preparation of stock
...but only in a few places in the world (Cornwall, in England, and Georgia, in the United States) are the deposits readily accessible and sufficiently pure to be used for pigment. Another pigment is titanium dioxide (TiO2), prepared from the minerals rutile and anatase. Titanium dioxide is the most expensive of the common pigments and is often used in admixture with others.
Inorganic pigments include white opaque pigments used to provide opacity and to lighten other colours. The most important member of the class is titanium dioxide. White extender pigments are added to paints to lower their cost or improve their properties. This class includes calcium carbonate, calcium sulfate, diatomaceous silica (the remains of marine organisms), and china clays. Black...
The most widely used white pigment is the crystal form of titanium dioxide (TiO2) known as rutile. Rutile has the highest index of refraction (2.76) of any material that can be manufactured in pigment form at a reasonable cost, making it the most efficient white pigment available. Another crystal form of TiO2, anatase, is sometimes used in coatings, but its lower index of...
TITLE: titanium (Ti): Compounds
Of the compounds formed by titanium in its +4 state, the dioxide, TiO2, is the most important. This nontoxic, pure white powder is used extensively as a pigment in paints, enamels, and lacquers. It occurs in nature as the minerals brookite, octahedrite, anatase, and rutile.
work of Honda and Fujishima
...the late 1960s and early ’70s, when Fujishima was completing his doctorate course work under Kenichi Honda’s supervision, the two found that a relatively inexpensive and widely available material, titanium dioxide, acts as a photocatalyst—a substance that facilitates a chemical reaction when it is exposed to sunlight. In their experiments titanium dioxide exposed to light caused water to...
...and early ’70s, Honda collaborated with Akira Fujishima, then a student whose doctoral course work he was supervising. The two found that a relatively inexpensive and widely available material, titanium dioxide, acts as a photocatalyst—a substance that facilitates a chemical reaction when it is exposed to sunlight. In their experiments titanium dioxide exposed to light caused water to...