Double-shell lignin microcapsules were prepared by one - step method for fabric coatings with UV resistance and durable antibacterial activity

The design and application of intelligent biomass microcapsules have gradually attracted widespread attention. In this study, double shell lignin microcapsules (DSLM) were prepared in one step by combining interfacial polymerization with free radical copolymerization. The biomass material lignin was grafted into the polyurethane shell at the interfacial polymerization stage to endow the microcapsule with a certain ultraviolet (UV) protection function. Lemon essential oil (LEO) with fragrance and antibacterial properties was further located at the core of the microcapsule and released by the thermal response. In the study, the morphological structure of the microcapsules and the release of the core material as well as the core-shell framework were characterized. Furthermore, these microcapsules were applied to the fabric coatings to give it UV protection and antibacterial properties. The whole preparation and functionalization process is facile and environmentally friendly. Due to the double-shell design, the encapsulated lemon essential oil is not easy to leak, which extends the antibacterial time and service life of the fabric coatings, and the release of the core material was controlled. At the same time, the outer shell of microcapsule plays a double protective role. These smart microcapsules are expected to be applied in outdoor fabric coatings and daily necessities in the future.