Bioinspired Slippery Zinc Phosphate Coating for Sustainable Corrosion Protection

Abstract

In this work, a slippery zinc phosphate coating composed with homogeneous pores was successfully fabricated by a facile method which was inspired by nepenthes pitcher plants. The as-prepared coating exhibited superhydrophobicity with a large water contact angle (WCA) of 156.6° after modification with fluoroalkylsilane (FAS) ethanol solution. A slippery surface with highly water-repellency was achieved by completely filling the Krytox 100 lubricant into the pores. Generally, based on the stable and low-volatile lubricant, a slippery surface can provide a better corrosion resistance than that of superhydrophobic surface for metals. Herein, this novel slippery coating also displayed an efficient and sustainable anticorrosion performance. The corrosion resistance was enhanced by 7 orders of magnitude compared with that of bare mild steel substrate. More importantly, the corrosion inhibition efficiency of this coating is still higher than 99.99% even after immersion in NaCl solution for 6 weeks, demonstrating an excellent long-term stability for corrosion protection. The coating has great potential to be used as antibacterial, anti-icing and water harvesting films.