Particle size titanium dioxide pigments

Inorganics are denser and usually of a larger particle size. Common inorganic pigments include iron oxides in buff colors, titanium dioxide in white, lead and zinc... 

EXAMPLE 2.2 Use of the Sedimentation Equation for Particle Size Determination. A titanium dioxide pigment of density 4.12 g cm 3 is suspended in water at 33°C. At this temperature, the density and viscosity of water are 0.9947 g cm-3 and 7.523 10-3 P, respectively. A particle size analyzer (SediGraph, Micromeritics Instruments Corp., Norcross, GA 30093) plots the following data for cumulative weight percent versus equivalent spherical radius ... 

The thermal activity of a series of nano- and micron-particle grade anatase and rutile titanium dioxide pigments, with various densities of surface treatments, particle size, and surface area, have been determined by chemiluminescence in monomodal metallocene polyethylene [57]. 

One year before the end of this period (in 1939), the first chalk-resistant pure titanium dioxide pigment was produced by the National Lead Co. Although never described as such at the time, this was also the first commercial rutile titanium dioxide, which accounted for some of its improved chalk resistance. Since the rutile structure had been attained by overcalcination, its overly large particle size and poor dispersibility prevented it from attaining the increased hiding power that should have accompanied its conversion to rutile, and the pigment was manufactured only until the end of World War II to satisfy the demand of the U.S. Navy for a durable titanium dioxide. 

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