Abstract:

The global ultraviolet radiation increases with the destruction of the ozone layer, causing potential harm to human health. Inorganic sunscreen usually have nanotoxicity, oxidation of active free radicals and negative effects on the ecosystem. Due to a large number of functional groups such as benzene ring, keto and phenol hydroxyl, natural lignin has the advantages of removing active free radicals and absorbing ultraviolet light, therefore the development of lignin-based anti-UV materials is of great importance. Inspired by the light protection mechanism of plant leaf structure, titanium dioxide/attapulgite （TiO₂/ATP） binary composite was prepared by precipitation method, and then TiO₂/ATP/dealkali-lignin （TiO₂/ATP/DL） nanocomposite was obtained by microwave hydrothermal method, and the composite was utilized for anti-UV application. Results show that needle-like TiO₂ is uniformly distributed on the ATP surface, thereby enhancing TiO₂ dispersion, and the abundant phenolic hydroxy in DL molecules and the aromatic rings formed p-π coupling enable them to absorb large amounts of UV light while generating interactions with TiO₂/ATP to further improve the UV absorption range. TiO₂/ATP/DL is added to the sunscreen lotion. The one-dimensional structure of ATP makes the emulsion structure more stable, and the formed sunscreen recovers quickly after damage, showing excellent sunscreen application.

Key words: lignin, UV resistance, biomimetic material, attapulgite, TiO₂