Eco-friendly design of superhydrophobic nano-magnetite/silicone composites for marine foul-release paints

• Published in: Progress in organic coatings 2018-03, Vol.116, p.21-34
• Main Authors: Selim, Mohamed S., Elmarakbi, Ahmed, Azzam, Ahmed M., Shenashen, Mohamed A., EL-Saeed, Ashraf M., El-Safty, Sherif A.
• Format: Article
• Language: English
• Subjects: Abrasion resistant coatings; Adhesion tests; Antifouling coatings; Atomic force microscopy; Atomic structure; Bacteria; Bacterial progenies; Bending modulus; Biological properties; Cleaning; Corrosion prevention; Crystal lattices; Durability; Electron microscopes; Energy consumption; Fillers; Fouling release; Fuel consumption; Good-distribution; Lotus effect; Magnetic properties; Mechanical properties; Modulus of elasticity; Nano-magnetite fillers; Nanocomposites; Polymer matrix composites; Polymers; Protective coatings; Seawater; Spectrum analysis; Studies; Sustainable development; Toxicity; Wettability
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2017.12.008

•Elastomeric silicone/controlled nanomagnetite composites were successfully fabricated.•Ecofriendly/economic nanocomposites were modeled via solution casting technique.•Controlling nanofiller dispersion is essential to improve different properties.•Anti-bactericidal activity was tested using microfoulants of diatoms/bacteria progeny.•The designed nano-system could be potentially applied in perfect FR self-cleaning. Advances in nanomaterials science are associated with developments fabrication methods in terms of energy saving, environment friendliness, and low cost. Self-cleaning nanocoatings with fouling release (FR) mechanism have been extensively investigated because of their non-stick, non-leachant, ecological, and economic advantages. Herein, we successfully modeled a series of self-cleaning technologies by using elastiometric siloxane polymer/nano-magnetite composites. The nanocomposite systems are dynamic non-stick surfaces and deter any fouling attachment through physical anti-adhesion. A series of superhydrophobic nanocomposites were synthesized through solution casting using different concentrations of nano-magnetite fillers. The fillers Exhibit 10–20nm particle diameter range and spherical shape facet mainly with the {311} crystal lattice plane. The composites were dispersed in linear ἀ,ὼ-dihydroxy polydimethylsiloxane (PDMS). Wettability characteristics, such as hydrophobicity, roughness, and free energy, were investigated by water contact angle analysis, field emission scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy to evaluate self-cleaning and FR features. The nanocomposites were also subjected to various tests on surface adhesion and mechanical properties, such as tensile modulus, impact, T-bending, crosscut, and abrasion resistance. The anticorrosive features were investigated through salt spray test in 5wt.% NaCl. Microfoulants of diatoms and bacterial progenies were selected and used to assess the anti-adhesion performance of the tailored nanosurfaces. The biological tests in laboratory was confirmed with a 3-month natural seawater field trial which indicated excellent inhibition of diatoms and bacterial growth and approved superior antifouling FR potential of the polymer/nano-magnetite (0.5%) composite hybrid coatings. This study provides insights into how structure–property relationship can enhance biological antiadhesion and FR performance. The uniform distribution of the nano-magnetite particle