Properties and Uses
The great versatility of titanium dioxide is owing to its various forms and sizes. Titanium dioxides may be used in the form of microscale pigments or as nano-objects. Their crystal structures may vary: Depending on the arrangement of TiO2 atoms, one differentiates between rutile and anatase modifications.
Due to its high diffraction index and strong light scattering and incident-light reflection capability, TiO2 is mostly used as white pigment. It is these properties and a high UV resistance that make TiO2 the standard pigment found in white dispersion paints with high hiding power. Since light scattering does not occur anymore in nanoscale particles, the white titanium dioxide pigments used are almost exclusively rutile modification particles with grain sizes in the micrometer range. These white pigments are not only found in paints and dyes but also in varnishes, plastics, paper, and textiles. Having E number E171, they are used as food additives and occur in toothpastes, several other cosmetics, and drugs. TiO2 pigments for use in plastics constitute the fastest growing market. It is in particular due to the packaging industry’s strong demand that the consumption of titanium dioxide pigments is on the increase.