Constructing industrial lignin into robust and multifunctional superhydrophobic coating for effective anti-icing
Liyunlong Wang, Zongwei Guo, Daliang Guo, Jian Li, Srinivas Janaswamy, Guihua Yang, Xingxiang Ji, Gaojin Lyu
Abstract
Using renewable materials as primary components for constructing superhydrophobic coatings is an effective strategy for enhancing the environmental sustainability of anti-icing technologies. Alkali lignin, a by-product of the pulp and paper industry, was graft-modified with 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane to create a robust and multifunctional superhydrophobic coating for effective anti-icing. The results demonstrated that the industrial lignin-based coating achieved a contact angle of 162.1°. Its robustness was evidenced by the fact that the contact angle showed no significant change after 400 vertical drop hammer impacts (with 100 g weights) and 900 cm of abrasion with 800-grit sandpaper. Furthermore, the coating versatility was confirmed through excellent self-cleaning properties, ultraviolet (UV) aging resistance, high-temperature durability, and substrate applicability. These characteristics provided a solid foundation for use of anti-icing coatings in extreme environmental conditions. More importantly, the superhydrophobic aluminum alloy samples exhibited outstanding anti-icing properties, as confirmed by low-temperature freezing delay and durability tests. The freezing time of the water droplets on the aluminum alloy sample was extended threefold, and the coating remained superhydrophobic for 10 days at -24 °C. This study offers new insights into the development of environmentally friendly anti-icing coatings and the value-added utilization of industrial lignin.