A Comparative Study on Anti-corrosion and Antifouling Performance of Marine High Density Polyethylene-Capsaicin Composite Coatings with Different Biocide Content

Artificial engineering materials suffer from serious marine corrosion and biofouling issues with the sustainable exploitation and utilization of marine resources. Thermal sprayed protective coating is an effective strategy for extending service life and reducing economic losses of maritime materials. This study focuses on developing anti-corrosion/fouling dual functional marine coatings via flame spraying the composites of high density polyethylene (HDPE) and eco-friendly biocide capsaicin (CAP). Attachment and colonization behaviors of marine bacteria and algae were measured to evaluate the antifouling performances of the coatings for 30 days. The HDPE-CAP (0.6%, 0.9%, and 2.0 wt.% capsaicin) composite coatings effectively inhibit adhesion, aggregation and accumulation of the Bacillus subtilis and Chlorella on their surfaces. The antifouling rates of HDPE-2.0CAP against Chlorella and B. subtilis are 81.9% and ~ 100%. Electrochemical tests were further conducted to evaluate the corrosion resistance of these coatings. The results showed that the HDPE and HDPE-CAP coatings exhibited better corrosion resistance than uncoated 316L stainless steel substrate. Overall, this study provides valuable insights into the development of novel thermal sprayed anti-corrosion/fouling coatings for potential marine applications, including marine engineering and biotechnology.