Physical Properties of Titanium Dioxide
Relative density: Among the commonly used white pigments, titanium dioxide has the smallest relative density. Among the white pigments of the same quality, titanium dioxide has the largest surface area and the highest pigment volume.
Dielectric Constant: Titanium dioxide has excellent electrical properties due to its high dielectric constant. When determining some physical properties of titanium dioxide, the crystallographic direction of titanium dioxide crystals should be considered. For example, the dielectric constant of the rutile type varies with the direction of the crystal. When it is parallel to the C axis, the measured dielectric constant is 180, and when it is perpendicular to this axis, it is 90, and the average value of the powder is 114. The dielectric constant of anatase titanium dioxide is as low as 48.
Conductivity: Titanium dioxide has semiconductor properties, its conductivity increases rapidly with temperature, and it is also very sensitive to oxygen deficiency. For example, rutile titanium dioxide is also an electrical insulator at 20°C, but its conductivity increases by a factor of 107 when heated to 420°C. Slightly reducing the oxygen content will have a special effect on its conductivity. According to the chemical composition of titanium dioxide (TiO2), the conductivity is <10-10s/cm, while the conductivity of TiO1.9995 is as high as 10-1s/cm. The dielectric constant and semiconducting properties of rutile titanium dioxide are very important to the electronics industry, which utilizes these properties to produce electronic components such as ceramic capacitors.
Rutile crystal structure
Hardness: According to the Mohs hardness scale of 10 points, the rutile titanium dioxide is 6~6.5, and the anatase titanium dioxide is 5.5~6.0. Therefore, in the chemical fiber extinction, the anatase type is used to avoid abrasion of the spinneret holes.
Melting point and boiling point: Since both anatase-type and brookite-type titanium dioxide transform into rutile-type at high temperature, the melting point and boiling point of brookite-type and anatase-type titanium dioxide do not actually exist. Only rutile titanium dioxide has a melting point and boiling point. The melting point of rutile titanium dioxide is 1850 °C, the melting point in air is (1830 ± 15) °C, and the melting point in oxygen-rich is 1879 °C. The melting point is related to the purity of titanium dioxide. The boiling point of rutile titanium dioxide is (3200±300)K, and titanium dioxide is slightly volatile at this high temperature.