Ceria (CeO2) has good anti-ultraviolet ability. The strength of CeO2’s anti-ultraviolet ability is related to its particle size: when the particle size is large, the anti-UV performance is mainly based on reflection and scattering, and it is effective for both medium-wave and long-wave ultraviolet rays, but the anti-ultraviolet ability is relatively weaker; when the particle size decreases, light can pass through the particle surface, and the reflection and scattering of long-wave ultraviolet rays are not obvious, and the small size effect and quantum size effect of the particles cause the absorption band to have a “blue shift” phenomenon, moving toward the short-wave direction, that is, the absorption of medium-wave ultraviolet rays is significantly enhanced, and the anti-UV ability is improved. Nano cerium dioxide has a small particle size with high activity. It can reflect and scatter ultraviolet rays, as well as absorb ultraviolet rays, so it has a stronger shielding properties against ultraviolet rays. When the nano sizes reach a certain small extend and are evenly and stably dispersed, nano ceric oxide has better ultraviolet shielding performance, increasing light quantum efficiency, absorption rate of ultraviolet rays, and can greatly improve visible light transmittance.
Compared with zinc oxide(ZnO) and titanium dioxide(TiO2), cerium dioxide has two advantages in anti-ultraviolet: first, its refractive index is lower than the other two, making the whiteness more natural; second, the UV light it absorbs is mainly through the transition of electronic energy levels, which will not cause photocatalysis, making it an ideal broad-spectrum inorganic ultraviolet shielding material.
Currently, nano cerium dioxide with excellent anti-ultraviolet performance is often used in the following fields:
Coatings: It can be considered to be added to the coating in combination with other materials. While playing an anti-ultraviolet effect, it can also improve aging resistance, mildew resistance, enhance the tensile strength and elongation at break.
Glass: Glass with the addition of cerium dioxidenanopowdercan not only enhance the shielding of glass against ultraviolet rays, but also improve the clear effect of glass.
Textiles: Textiles with the addition of nano cerium dioxide have significantly improved anti-ultraviolet performance, and the effect is still lasting after multiple washings.
Sunscreen products: Good transparency, good anti-ultraviolet effect and show more natural color.
The research on the anti-UV properties of nano cerium dioxide is still deepening, and its application is constantly improving. It is believed that in the future, the use of nano cerium dioxide will be more extensive and its advantages will be further utilized.