Synthesis and characterization of a broad-spectrum TiO₂@lignin UV-protection agent with high antioxidant and...

TiO₂ with biocompatibility and low price was limited application in cosmetics due to its narrow UV protection range, producing free radicals under UV irradiation to accelerated skin aging and whitish. Herein, a series of highly effective broad-spectrum TiO₂@lignin sunscreen microscopes (TWLx) were prepared by modulating van der Waals forces and hydrogen bonding interactions between TiO₂ and lignin. The results showed that the UV main absorption peak of TWLx increased from UVA to UVA + UVB. TWLx could completely eliminate the hydroxyl radical produced by TiO₂ under UV irradiation owe to introduction of lignin. Meanwhile, the combination of TiO₂ and lignin could neutralize color, which made TWLx color closer to human skin. The UV-protection test showed that the SPF value of sunscreen containing 3 wt% TWLx reached 137.4. The antioxidant experiment showed that TWLx has about 16 times the DPPH radical scavenging ability of TiO₂. Finally, high internal phase Pickering emulsions were prepared by using TWLx as a stabilizer. It was found that the internal phase volume fraction of the emulsion was up to 86 vol%, which could be recognized as the highest internal phase reported in suntan lotion. This work would provide new ideas for the synthesis of highly effective broad-spectrum sunscreens.