UV-curing fabrication of universal superhydrophobic coatings based on modified hemp stalk cellulose for multifunctional applications

The poor interfacial adhesion and limited durability of conventional cellulose-based superhydrophobic coatings hinder their practical applications. Herein, we report a robust and universal superhydrophobic coating fabricated from hemp stalk-derived micro-nano cellulose (MNC) via a rapid UV-curing strategy. The MNC was strategically modified to create vinyl-functionalized filler (MMNC), which forms a covalently cross-linked micro-nano network with an epoxy vinyl resin under 30 s of UV irradiation. The resulting coating exhibits a water contact angle (WCA) of 155.7° and demonstrates exceptional durability, maintaining superhydrophobicity (WCA > 150°) after severe tests including sandpaper abrasion, prolonged exposure to extreme pH (1−13) environments, UV irradiation for 288 h, and 30,000 stretching cycles (up to 200 % strain). Multifunctional applications are showcased, such as self-cleaning and anti-icing on glass (delaying freezing time to 470 s), efficient oil-water separation on filter paper, and significantly enhanced corrosion resistance on steel, with an electrochemical impedance modulus three orders of magnitude higher than that of the pure resin after 50 d in salt spray. This work provides a scalable, energy-efficient, and biomass-based platform for high-performance protective coatings. • A superhydrophobic coating was developed from modified hemp stalk micro-nano cellulose. • UV-curing rapidly formed a robust micro-nano composite network within 30 s. • The coating shows excellent durability against abrasion, stretching, and chemicals. • It exhibits multi-functionality including self-cleaning, anti-icing, and oil-water separation. • Superior corrosion protection on metals was demonstrated with high impedance.