Superhydrophobic cotton fabric with excellent healability fabricated by the “grafting to” method using a diblock copolymer mist

A diblock copolymer, poly[(methyl methacrylate)-b-(trifluoroethyl methacrylate)] (PMMA-b-PTFMA), was synthesized via RAFT polymerization and was used to fabricate a healable superhydrophobic layer on cotton fabric surfaces via a mist treatment using an acetone solution. The PMMA block in the copolymer enabled covalent linkages with cellulose molecules on the fiber surface via transesterification reactions, while the PTFMA block acted as a functional part to endow the cotton fabric with new surface features. As a result, the modified cotton fabric displayed superhydrophobicity, with a water contact angle (WCA) above 160°. The resulting layer also exhibited excellent stability against laundering and abrasion. Even after 60 laundering cycles or 2000 abrasion cycles, the fabric still demonstrated a WCA higher than 140°. Moreover, this superhydrophobic property could be renewed using the common dry-cleaning agent, perchloroethylene (C2Cl4). This mist-modification approach was shown to have insignificant impacts on the desired cotton properties. The flexibility, water absorptivity, and vapor permeability of the original cotton fabric were largely preserved.