Supersonic Copper Particle Embedment to Prevent Marine Biofouling

Application of paint loaded with copper compounds is a common method for deterring settlement of marine organisms onto man-made infrastructure. However, painting is often impractical or suffers poor adhesion to low surface energy polymers or flexible objects such as cables. An alternative solution, developed at the CSIRO, Australia is to embed antifouling particles into the surface of soft polymers by cold spray. The particles remain in contact with the environment via the impact tunnels. In this paper, copper, copper alloy, silver-coated copper and Cu₂O particles were embedded into polyurethane at particle loadings 53 – 431 g/m². To assess antifouling efficacy, 50 × 50 mm samples were cut and deployed in field trials at Queenscliff, Australia. There was a clear correlation between loading and rate of fouling accumulation, while pure copper particles slightly outperformed copper alloy and silver-coated particles. Particle degradation mechanisms were studied by immersing samples in a tank of flowing, filtered seawater and examining at intervals by XRD and ICP-OES.