Universal, mechanically robust and self-healing superhydrophobic coatings enabled by covalent adaptable networks of disulfide bonds

Abstract

Covalent bonding and self-healing ability offer superhydrophobic coating high durability, however, the barrier to the migration and self-healing is obvious due to its covalent network and high glass transition (Tg) temperature. In this work, we design a novel strategy for incorporating covalent adaptable networks of disulfide bonds into superhydrophobic surfaces by coating cotton fabric for its mechanical robustness and processability, which is based on enzyme etching and subsequent oxidation coupling of sulfhydryl alkyl silane (MPTES) and (mercaptopropyl)methylsiloxane-dimethylsiloxane copolymers (S-PDMS). The super water-repellency is durable enough even after 25 cycles of repeated accelerated washing or 2000 cycles of Martindale abrasion. The dynamic adjustment of covalent adaptable networks of disulfide bonds happens upon heat stress, which allows lower temperature (90 °C) for the self-healing on superhydrophobicity. The grafting of MPTES and disulfide coupling reaction make the route available to other substrates. Such a novel way for preparing covalent adaptable networks may promote the development of durable functional coatings and routine maintenance.