Superhydrophobic silicone/graphene oxide-silver-titania nanocomposites as eco-friendly and durable maritime antifouling coatings

Abstract

In this work, a novel ecofriendly series of polydimethylsiloxane-polymethylmethacrylate (PDMS-PMMA) blend filled with silver nanospheres and titanium dioxide nanorods grafted on the graphene oxide surface (Ag–TiO2@GO) were produced by the catalytic hydrosilation method as outstanding marine antifouling coatings. Innovative Ag–TiO2@GO hybrid nanofillers, that would release fouling and confer surface robustness, were developed by a single-phase procedure. Ag nanospheres with 20 nm mean diameter were prepared by a controlled solvothermal method, while anatase TiO2 nanorods with 10 nm average diameter were grown by a hydrothermal technique. The solution casting method was used to distribute various Ag–TiO2@GO filler percentages throughout the silicone matrix. Atomic force microscopy, surface free energy, and water contact angle (WCA) were employed to examine the superhydrophobicity and roughness of the coatings. The mechanical durability and antifouling characteristics of the PDMS-PMMA nanocomposites filled with Ag–TiO2@GO composites were also investigated. Several microorganisms were employed to examine the fouling resistance of the coated specimens for 30 days. Trichogaster lalius fish and the bivalve Brachidontes variabilis species were used to examine the nanocomposites’ toxicity. Well-dispersion of Ag–TiO2@GO nanofillers in the PDMS-PMMA resin until 2.5 wt% exhibited the highest WCA (160° ± 2°), the lowest surface free energy (22.9 mN/m), rough topology, and improved bulk mechanical properties. Furthermore, the well-dispersed PDMSPMMA/Ag–TiO2@GO (2.5 wt%) nanocomposite presented the lowest biodegradability percentages and optical density against various gram-positive and gram-negative bacterial strains. Furthermore, it displayed non-toxicity against the tested species of fish and bivalve. The developed non-toxic and non-stick nanocoating exhibited various merits, including superhydrophobicity, mechanical robustness, and fouling retardancy, for using as maritime ship hull coatings.