High-purity high density violet tungsten oxide’s color can reflect its quality. Moreover, the color of violet tungsten oxide is related to its oxygen index, tightness of particles and aspect ratio of needle. The purple-colored violet tungsten oxide has a slightly higher oxygen index, slightly thinner and longer needles; And the mauve-colored violet tungsten has slightly coarser and shorter needles.
The quality of violet tungsten oxide can be determined by colorimetry. This method is more intuitive and effective, which saves time and money.
However, during the normal production of violet tungsten oxide, there are non-needled small particles, which exist among uneven particles and are affected by those tungsten oxides lower than WO2.72, but not the impurity. These non-needled small particles are only different from needle-shaped particles in oxygen index. Violet tungsten oxide with few non-needled small particles, that is, high quality violet tungsten oxide, may be obtained by using APT with uniform particles or tungstic acid as raw material.
More details, please visit:
http://www.tungsten-powder.com/violet-tungsten-oxide.html