Core-shell structured nets for biofouling control in aquaculture

Abstract This study demonstrates a robust, flexible interpenetrated composite based on 3D spined fabrics as core material and polydimethylsiloxane (PDMS) as shell material. The penetration of the shell component into the core material enables the mechanical interlocking at the micro and macro scale, providing mechanical stability and at the same time, introducing hydrophobic surface properties. Pure PDMS is a well-known biofouling-release material, showing drawbacks with respect to mechanical strength and adhesion-to-substrate, which can be overcome by the presented approach. Nowadays, antifouling strategies for aquaculture nets are realized by using biocide-containing coatings to avoid the attachment of organisms or repel them. Up to now, there are no coatings available on the market that provide adequate biofouling protection for aquaculture nets during the whole production cycle of the cultured stock. Even biocidal coatings exhibit a limited efficiency and need to be regularly cleaned, causing a substantial loss of the coating and increased emissions of biocides into seawater. This proof-of-concept study covers the scope from the design and production of the composite up to the first field tests in the Baltic Sea. The presented approach enabled by material science facilitates a fundamentally different approach in biofouling management and contributes to sustainable aquaculture.