Hangzhou Harmony Chemical Co.,Ltd
sustainable development
Titanium Dioxide Whiteness
Most of the whiteness annotations are compared with the standard sample or expressed with L, a and b. Almost all application fileds require good whiteness. The impurity of titanium dioxide and particle dialogue degree have significant influence on tio2 whitness. The international lighting associationCIE, short for commission internationals DE eclairage has set out L*, a* and b* values to measure the color value. This method is called CIELAB. L* stands for lightness, from brightness (L*=100) to darkness (L*=0).A * stands color from green (A *) to red (+ A *), and b * stands color from yellow (+ b *) to blue (b *).

Main factors affecting the titanium dioxide whiteness:

(1) the types and contents of harmful impurities in titanium dioxide: the content of harmful impurities, such as iron, chromium, cobalt, cerium, copper, manganese, vanadium, lead, etc. will have obvious affect on the whiteness. This is because of the color effect of impurities themselves, and because of the presence of impurity ions, especially heavy metal ions, the distortion of the lattice curves of titanium white powder has lost its symmetry.

Rutile type titanium pigment is perticularly sensitive to the influence of impurities. For example if the iron oxide content is more than 0.003% in the rutile type titanium pigment, it will present the color, but the anatase tio2 wil appear colors only whenit reaches to more than 0.0099%.

(2) shape and size distribution of titanium dioxide particles: the particle shape of titanium dioxide requires smooth contour, without edges and corners, because the surface of edges and corners will reduce the reflection of light. The particle size should be controlled between 0.2 and 0.4 microns, that's about half the wavelength of visible light, so that you can get high light scattering, making it even whiter.When the particle size is less than 0.1 micron, the crystal is transparent;When the particle size is too large, that is more than 0.5 micron, it can reduce the scattering ability of particles to light, which may have a very harmful effect on pigment performance. For particle size distribution, uniform and narrow distribution is required.
Related News
  • Titanium Dioxide Synthesis

    Titanium Dioxide Synthesis

    January 22, 2018Gas Phase Oxidation:Gas phase oxidation was carried out with dry oxygen at 923K-1023K:TiCl4 + O2 = TiO2 + 2 cl2Sulfuric Acid Method:In the first place, the soluble sulfates were prepared by using the ...view
  • Tio2 Density

    Tio2 Density

    January 22, 2018The relative density of titanium dioxide is related to its crystalline form, particle size, chemical composition, especially the size of surface treatment. During the manufacturing process, the relati...view
  • Tio2 Structure

    Tio2 Structure

    January 22, 2018There are three forms of Tio2 in the natural environment, including rutile, anatase and brookite with different properties, among which rutile Tio2 is the most stable one of tio2 and it will never con...view
  • Titanium Dioxide Whiteness

    Titanium Dioxide Whiteness

    January 22, 2018Most of the whiteness annotations are compared with the standard sample or expressed with L, a and b. Almost all application fileds require good whiteness. The impurity of titanium dioxide and particl...view
  • Titanium Dioxide Chemical Properties

    Titanium Dioxide Chemical Properties

    January 22, 2018The chemical properties of titanium dioxide are very stable. As a kind of acidic amphoteric oxide, Tio2 does not act with other elements and compounds at normal temperature, and it does not act on oxy...view
  • Titanium Dioxide Dispersion

    Titanium Dioxide Dispersion

    January 22, 2018Simply, the dispersion is the degree of scatter particles of pigment occurring in the medium of the base in certain condition of dispersion and time. Or under certain condition of dispersion, the need...view
  • TEL:+86-0571-56189835
  • FAX:+86-0571-87247555
  • EMAIL:sales@chinaharmony.cn
  • ADDRESS:31 Floor,Sunon Central Mansion, No.200 Civilian Street, Qianjiang CBD, Hangzhou, Zhejiang, China