Nanofibrillated cellulose-based superhydrophobic coating with antimicrobial performance

Superhydrophobic coatings have been widely developed to endue the materials with antibacterial, self-cleaning, antiseptic, and some other multifunctionalities. 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 cellulose-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 nanoroughness, 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 exhibited a certain degree of antibacterial performance. This work provides a good approach for not only the high-value application of cellulose but also the development of ecological and sustainable multifunctional coatings.