Function of nanometer titanium dioxide (2)

4. Anti ultraviolet function

Self dispersive nano titanium oxide manufacturers to explain the anti ultraviolet function of nano titanium dioxide. Nano titanium dioxide can not only absorb ultraviolet light, but also reflect and scatter ultraviolet light, and can pass through visible light. It is a physical shielding type ultraviolet protective agent with superior performance and great development prospect.

The anti ultraviolet mechanism of nano-TiO2 is as follows

According to the different wavelengths, ultraviolet rays are divided into short wave region 190-280 nm, medium wave 280-320 nm and long wave 320-400 nm. The ultraviolet energy in the short wave region is high, but it is blocked when passing through the ozone layer. Therefore, the damage to the human body is generally in the medium wave area and the long wave area. The strong UV resistance of nano-TiO2 is due to its high refractive index and high light activity. The ultraviolet resistance and its mechanism are related to the particle size: when the particle size is large, the main barrier to ultraviolet radiation is reflection and scattering, and it is effective for ultraviolet rays in medium and long wave regions. The mechanism of sunscreen is simple covering, which belongs to the general physical sunscreen, and the sunscreen ability is weak; with the decrease of particle size, the light can pass through the particle surface of nano titanium dioxide, and the reflection and scattering of ultraviolet light in long wavelength region is not obvious, but the absorption of ultraviolet in medium wave area is obviously enhanced. Its sunscreen mechanism is to absorb ultraviolet rays, mainly absorbing ultraviolet rays in the middle wave region. It can be seen that the mechanism of Nano-TiO2 on UV protection of different wavelengths is not the same. The main barrier of nano-TiO2 to UVB is scattering, and the main barrier to UVB is absorption. Compared with other organic sunscreen agents, nano-TiO2 has stable performance and good effect. Shiseido Japan uses 10-100nm nano titanium dioxide as a sunscreen ingredient to add lipstick and cream, and its sun protection factor can be SPF11-19. Due to its small particle size and high activity, nano-TiO2 can reflect and scatter ultraviolet rays and absorb ultraviolet rays, so it has stronger blocking ability to ultraviolet rays. Compared with some organic UV protectors of the same dose, the absorption peak of vk-t02 nano-TiO2 in the ultraviolet region is higher. What is more valuable is that it is also a broad-spectrum shielding agent, which does not only absorb UVA or UVB as organic UV protectors. It can also pass through visible light. When added to cosmetics, the skin whiteness is natural. Unlike pigment grade TiO2, it cannot penetrate visible light, resulting in unnatural pale color on the user's face. Nano-TiO2 can also be used as food packaging film, ink, coating, textile products and plastic filler by using its transparency and ultraviolet absorption capacity. It can replace organic ultraviolet absorber and improve the aging resistance of coatings.