Nanofibrillated lignocellulose-based superhydrophobic coating with antimicrobial performance

Superhydrophobic coatings have been widely developed to endue the materials with antibacterial, self-cleaning, antiseptic, and some other multi-functionalities. Fluorochemicals are the most commonly used superhydrophobic coatings, however, the released toxic substances from fluorinated polymers are a significant source of water pollution and even a threat to human health. With the increasingly great attention to the environment, it is imperative to exploit green and effective hydrophobic coatings. Here, a nanofibrillated lignocellulose-based multifunctional superhydrophobic coating (NMSC) was fabricated by using an efficient silylation process from cellulose, tetraethyl orthosilicate, and cetyl trimethoxysilane. Microscopic, chemical structural, and thermal properties analyses revealed that the NMSC has nano roughness, low surface energy, and good thermal stability. More importantly, the NMSC displayed an unprecedented hydrophobic and self-cleaning performance (water contact angle ~ 165°). The NMSC superhydrophobic coating can realize long-term effective barriers to many fluids, including strong acid (pH = 1), strong alkali (pH = 13), alcohols, alkanes, esters, and some other organic solvents. Moreover, the NMSC also showed good antibacterial properties with E. coli and S. aureus . This work not only improved the high-value application of lignocellulose but also provides a good pathway for the development of ecological and sustainable multi-functional coatings.