Spraying Preparation of Eco-Friendly Superhydrophobic Coatings with Ultralow Water Adhesion for Effective Anticorrosion and Antipollution

Abstract

Sustainability, eco-efficiency, and green chemistry guide the development of new materials in various fields. Herein, we designed and fabricated bio-based superhydrophobic coatings by means of a facile spraying synthesized method. The as-prepared superhydrophobic coatings exhibited high water repellency with higher water contact angle being up to 156.9 ± 2.7° and a lower sliding angle of only 4.3 ± 0.6°. Also, the water adhesion on the superhydrophobic coatings was as low as 11 μN, which was far less than that (346 μN) of the normal polyurethane surfaces. The superhydrophobic properties still retained high stability under the conditions of soaking in acid solution (pH = 1) and alkaline solution (pH = 13). Meanwhile, the as-prepared bio-based superhydrophobic coatings were verified for effective corrosion and pollution protection ability. The electrochemical measurements showed excellent corrosion resistance with a higher corrosion voltage of -204.7 mV and lower corrosion current of 1.494 × 10-5 A/cm2. The corrosion protection efficiency reached a value of 95.2%, and meantime, the superhydrophobic coatings displayed higher antipollution performance without any stains when they were removed from the polluted liquids. On this basis, the underlying physical-chemical mechanisms clearly revealed that the surface micro-nanostructures could capture the continuous and stable air layer to segregate the corrosion and pollution media.