Fabrication of mechanically stable UV-curing superhydrophobic coating by interfacial strengthening strategy

Abstract

UV-curing superhydrophobic coatings, which have high efficiency and energy saving characteristics, have wide application prospects, but still face some challenges, such as limited mechanical stability and low adhesive force. Herein, a durable UV-curing superhydrophobic polyurethane acrylic (PUA) coating was prepared via an interfacial strengthening strategy. Nano-SiO2 grown in situ on the surfaces of carboxylated carbon nanotubes (CNTs) were used to strengthen the interfacial interaction between the particles and reduce the barrier effect of the nanoparticles on the resin monomers. The CC bonds on the CNTs@SiO2 particle surface, which were grafted with 3-methacryloxypropyltrimethoxysilane (MPS), improved the lateral film-forming properties of the coating as the PUA monomers polymerized with the unsaturated CC bonds. Additionally, the longitudinal bonding between the coating and metal surface was enhanced by the addition of MPS, which acted as a bridge that connected the CC bonds of PUA to the hydroxyl group on the metal surface. Because of the aforementioned interfacial strengthening in both the vertical and horizontal directions, the superhydrophobic PUA/MPS/CNTs@SiO2 coating exhibited excellent adhesion (0 grade) and maintained superhydrophobicity even after 1500 cycles of abrasion. In addition, the prepared superhydrophobic coating also possessed good UV-resistance, self-cleaning properties, and could withstand impact by water droplets (4.4 m/s) and sand.