Research of Cu-bearing stainless steel with inhibition function of biofouling formation in freshwater environment

316L SS is widely used but is prone to algae adhesion, making biofouling a big challenge for the long-term functionality and reliability in freshwater. Most reported organic antifouling coatings are not suitable for use in freshwater environments, making copper-containing stainless steels a good candidate for freshwater antifouling. Anti-fouling resistance of 316L-Cu SS and 316L SS was compared using a self-built natural simulation ecosystem in this study. The results demonstrated that the algae adhesion percentage on 316L-Cu SS is much lower than that on 316L SS from both macro and micro perspectives using a single-lens reflex camera and high sensitivity structured illumination microscope. Results of this study clearly revealed that the mechanism of algae resistance for 316L-Cu SS is the release of Cu2+ can inhibit the adhesion of proteins and polysaccharides, weakening the adhesion of the extracellular polymeric substances to the metal substrate and even make the attached diatoms fracture or damage. This study provides a novel strategy to prevent algae adhesion on metal surface for an array of underwater equipment used in freshwater and contributes towards the advancement of materials used for underwater equipment, fostering enhanced performance and reduced maintenance in freshwater applications and the mitigation of algae fouling in aquatic environments.