Novel graphene-based ternary nanocomposite coatings as ecofriendly antifouling brush surfaces

Abstract

Since the ban on TBT compounds in antifouling paints in 2003, silicone foul-release (FR) coatings have elicited increasing attention and market share as environmentally benign and cost-effective alternatives. Herein, the catalytic hydrosilation approach was used to develop a series of elastomeric nanocomposites of polydimethylsiloxane top coat packed with graphene oxide (GO) sheets ornamented with anatase TiO2 nanorods (GO/TiO2 NRs). A simple two-phase process was used to create a unique, simple, cost-effective, and environment-friendly GO/TiO2 nanocomposite. The GO surface containing epoxy, OH, CO, and COOH results in the adhesion of TiO2 NRs to the surfaces via charge-transfer interaction and physisorption including π–π interactions and hydrogen bondings. To investigate the structure–property relationship, different concentrations of GO/TiO2 nanofillers were injected into the composite top coat nanosurfaces through an in situ approach. A controlled hydrothermal technique was used to successfully prepare single crystals of organic-capped anatase TiO2 NRs with 10 nm mean width, 20 nm length, and growth in the [101] direction. Surface nonwettability with rough topological structure and low surface free energy (SFE) has sparked considerable attention. The obtained virgin and GO/TiO2 filled composites' physical, mechanical, and anticorrosive properties were also examined. Various microfouling species were selected to test the biological inertness of the coated specimens for up to four weeks in the laboratory. The findings shed light on the impact of GO/TiO2 filler distribution and topological roughness to enhance the modeled nanopaints' fouling repellency and superhydrophobicity. The water-contact angle (152°) considerably increased, the SFE (12.3 mN/m) decreased, and the rough topology improved with the addition of nanofillers until 1 wt% without any changes in the bulk mechanical characteristics. A 45-day field trial in natural seawater was carried out in a tropical area to confirm the coatings' durability and FR performance based on the screening process and image analysis. Thus, we obtained a promising FR nanocomposite top coat for marine coating applications and healthcare facilities with great thermal stability, superhydrophobicity, surface inertness against fouling adherence, cost-effectiveness, and increased lifetime.