Graphite Oxide (GrO)-Based Polyethylene Composites as Antifouling Materials for Aquaculture and Marine Renewable Energy

Abstract

Marine structures used in aquaculture farms and offshore renewable energy systems are constantly exposed to biofouling, the unwanted accumulation of microorganisms, algae, and invertebrates on submerged surfaces, which increases maintenance costs and reduces operational efficiency. This study develops antifouling (AF) materials based on a LLDPE matrix modified with graphite oxide (GrO). GrO is synthesized by treating graphite with a mixture of sulfuric and phosphoric acids, and the product with intermediate oxidation is selected for incorporation into polyethylene matrices at 1, 3, and 5 wt%. Test panels are prepared by molding the composites and subsequently exposed to real marine conditions in two zones—splash (0.1 m) and submerged (0.6 m)—for 12 months. Results show that panels containing 5 wt% GrO present a significant reduction in biofouling biomass compared to the unmodified polyethylene control, particularly under splash conditions where organism colonization is most aggressive. Statistical analysis confirms significant differences between GrO-modified panels and the control (p < 0.05), with biofouling reduction reaching 305% for PE-5GrO. These findings validate the AF efficacy of GrO and demonstrate its applicability in aquaculture and marine renewable energy systems. Further studies should address ecotoxicity, leaching dynamics, and mechanical durability under open-sea conditions.