Preparation of Light-Colored Lignosulfonate Sunscreen Microcapsules with Strengthened UV-Blocking and Adhesion Performance

Inspired by the UV-blocking of lignin in plants and the adhesion of catechol in mussel dopamine, light-colored lignin-based microcapsules ((OMC + BMDM)/LS-OH₃-T) with strengthened UV-blocking and good bioadhesion were obtained by demethylation modification of sodium lignosulfonate (LS) and encapsulation of chemical sunscreen actives. The results show that the adhesion between LS and skin improved from 0.158 to 0.173 mN/m due to the formation of catechol groups. When (OMC + BMDM)/LS-OH₃-T was used as the unique active ingredient in the sunscreen, the sun protection factor (SPF) reached 86.67, fully meeting the daily sunscreen requirement. In addition, the color of microcapsule-based sunscreen was close to pure white, which effectively solves the dark color problem of the existing lignin-based sunscreens. As it demonstrates good biocompatibility, this new light-colored lignin-based sunscreen agent has good application potential in the skincare field.