GNP/Ag@PDA Incorporated Waterborne Epoxy Coating with Excellent Corrosion Resistance and Antifouling Performance

Corrosion and fouling problems are two main challenges for devices working in the ocean. However, most existing solutions lack the ability to concurrently obtain corrosion resistance and antifouling behavior. Here, a novel waterborne epoxy (WEP) based composite coating that has remarkable resistance to corrosion and fouling is developed. The WEP-based composite coating consists of nanohybrid filler prepared by loading silver (Ag) nanoparticles on graphite nanoplatelets (GNP) surface through a facile in situ hydrothermal synthesis and polydopamine (PDA) modification. The PDA modification effectively improves the dispersion and compatibility of GNP/Ag@PDA (GAP) with the WEP matrix. The synergistic effect of Ag with chemical antifouling behavior and GNP with physical barrier function endows the GAP/WEP composite coating with a low corrosion rate of 1.04 × 10⁻⁷ mm a⁻¹ after immersing in 3.5 wt.% NaCl solution for 28 days, which is about two orders of magnitude lower than that of blank WEP coating, and a high inhibition rate of 90.81% after immersing in Phaeodactylum tricornutum solution for 7 days. This approach has the potential to address the needs of a range of applications around anticorrosion and antifouling in the ocean.