Bioinspired Graphene Oxide–Magnetite Nanocomposite Coatings as Protective Superhydrophobic Antifouling Surfaces
Mohamed S. Selim, Nesreen A. Fatthallah, Mohamed A. Shenashen, Shimaa A. Higazy, Hekmat R. Madian, Mahmoud M. Selim, Sherif A. El‐Safty
Abstract
Antifouling (AF) nanocoatings made of polydimethylsiloxane (PDMS) are more cost-efficient and eco-friendly substitutes for the already outlawed tributyltin-based coatings. Here, a catalytic hydrosilation approach was used to construct a design inspired by composite mosquito eyes from non-toxic PDMS nanocomposites filled with graphene oxide (GO) nanosheets decorated with magnetite nanospheres (GO–Fe 3 O 4 nanospheres). Various GO–Fe 3 O 4 hybrid nanofillers were dispersed into the PDMS resin through a solution casting method to evaluate the structure–property relationship. A simple coprecipitation procedure was used to fabricate magnetite nanospheres with an average diameter of 30–50 nm, a single crystal structure, and a predominant (311) lattice plane. The uniform bioinspired superhydrophobic PDMS/GO–Fe 3 O 4 nanocomposite surface produced had a micro-/nano-roughness, low surface-free energy (SFE), and high fouling release (FR) efficiency. It exhibited several advantages including simplicity, ease of large-area fabrication, and a simultaneous offering of dual micro-/nano-scale structures simply via a one-step solution casting process for a wide variety of materials. The superhydrophobicity, SFE, and rough topology have been studied as surface properties of the unfilled silicone and the bioinspired PDMS/GO–Fe 3 O 4 nanocomposites. The coatings’ physical, mechanical, and anticorrosive features were also taken into account. Several microorganisms were employed to examine the fouling resistance of the coated specimens for 1 month. Good dispersion of GO–Fe 3 O 4 hybrid fillers in the PDMS coating until 1 wt % achieved the highest water contact angle (158° ± 2°), the lowest SFE (12.06 mN/m), micro-/nano-roughness, and improved bulk mechanical and anticorrosion properties. The well-distributed PDMS/GO–Fe 3 O 4 (1 wt % nanofillers) bioinspired nanocoating showed the least biodegradability against all the tested microorganisms [ Kocuria rhizophila (2.047%), Pseudomonas aeruginosa (1.961%), and Candida albicans (1.924%)]. We successfully developed non-toxic, low-cost, and economical nanostructured superhydrophobic FR composite coatings for long-term ship hull coatings. This study may expand the applications of bio-inspired functional materials because for multiple AF, durability and hydrophobicity are both important features in several industrial applications.