Silicone/graphene oxide sheet-alumina nanorod ternary composite for superhydrophobic antifouling coating

Abstract

Superhydrophobic silicone fouling-release (FR) nanocomposite coatings have gained considerable interest as an eco-friendly and economic solution to combat biofouling problems of ship hulls. In this work, graphene oxide anchored with alumina nanorods (GO-Al2O3 NRs) sheet hybrids were fabricated via a two-phase method. A ternary nanocomposite series of elastomeric silicone/GO-Al2O3 hybrid NRs sheet coating was developed via solution-casting method. γ–Al2O3 NRs of 150 nm in length and 20 nm in diameter were fastened between GO nanosheets and conformably coated with silicone layers. Different concentrations of GO-Al2O3 hybrid NRs sheet fillers were inserted in the silicone composites to study the structure property relationship. Nanocomposites’ surface characteristics, such as superhydrophobicity, surface free energy (SFE), and rough topology were investigated here. The physical and mechanical characteristics of the coating materials were also considered. Selected micro-foulants were used for the investigation of biological inertness. Laboratory assessments were performed on coated specimens for up to 28 days. A rigorous field trial was carried out for the fabricated model in natural marine water for 3 months. Well-dispersed GO-γ-Al2O3 NRs sheets hybrids of up to 1 wt.% increased the contact angle (151°), decreased the SFE (13.25), and provided micro-nano roughness. Thus, a promising FR nanocomposite coating was approved with superhydrophobicity, high thermal stability, and economic savings for marine coating applications.