Modeling of spherical silver nanoparticles in silicone-based nanocomposites for marine antifouling

Since the use of organotin antifouling paints was prohibited in 2003, researchers have endeavored to develop novel environment-friendly marine antifouling coatings. We report the successful fabrication of model silicone foul-release (FR) coatings with elastomeric polydimethylsiloxane (PDMS)/spherical silver (Ag) nanocomposites. This design integrates two inhibition modes of (1) chemical inertness and (2) the physical repelling force of microfouling. The antifouling nanocomposite models were successfully synthesized via the solution casting technique. In this approach, a series of filler concentrations of Ag nanoparticles (NPs) with a particle size of <10 nm and spherical morphology facet dominantly controlled on the {111} lattice plane was used to control the antifouling models. The surface hydrophobicity, roughness, and free energy properties of the nanocomposites were systematically studied as fouling non-stick factors. The physicomechanical properties were also assessed. Selected bacterial strains were used as microfoulants for a laboratory assay investigation for 30 days. Our findings provide important insights into how subtle structural changes in polymer nanocomposites can considerably improve biological activity and simplify surface cleaning. Hydrophobicity, surface inertness, fouling resistance, and surface easy-cleaning properties significantly improved in the nanocomposite design models fabricated with nanofiller loadings of up to 0.1% spherical Ag NPs without changes in the bulk mechanical properties. The fabricated models were subjected to a rigorous test in a field trial in Red Sea water. The results show the potential of our models based on Ag nanofillers up to 0.1% for ecologically friendly antifouling coatings as an alternative to traditional systems. The PDMS/Ag composite models have a long-term durability and antifouling performance, which are important factors for developing effective, stable, and eco-friendly nanocomposites.