Nanocoatings are under development for marine applications that are mechanically and chemically resistant against sand, salts, enzymes, and bio-compounds produced by marine life.
Biofouling is a major problem in the marine industry. When organisms such as bacteria, barnacles and algae stick to the surfaces of ships it is a costly nuisance. Biofouling negatively impacts maritime activities, creating biological films on different structures. Due to biofouling, regular maintenance and the use of biocides is needed, which interrupts maritime operations and contaminates water.
These biofouling organisms mean that ships burn 40% more fuel at an annual cost of more than €5 million for businesses, as well as an incalculable cost to the environment.
Nanocoatings can restore original color, extreme gloss, surface hardness and UV resistance back into oxidized clear coatings on marine vessels. Fouling organisms have traditionally been controlled through the application of antifouling paints that release biocides. Regulations now require that antifouling paints must not cause significant adverse effects on the environment. Nanomaterials allow for environmentally benign coatings. Biofouling can be minimized by reducing bio-adhesion via nanomaterials. Non-stick nanocoatings prevent adhesion of marine life to ships hulls.
Nanocoatings have been applied in military and commercial steel ship hulls and steel, aluminum or fiberglass boat hulls, making them non-susceptible to permanent adhesion of marine fouling organisms such as barnacles, sea-grasses etc. Nanostructured cemented carbide coatings are used on US Navy ships for their increased durability. Carbon nanotubes (CNT) have been incorporated into marine coatings for anti-corrosion. These coatings allow for Improved integrity of barrier films due to lower pigment loading and CNT reinforcement. They also display improved durability and modulus understress and impact and abrasion resistance.
Graphene is also under developed by a number of companies for application in impermeable rustproof coatings for ships.
Advanced Marine Coatings (www.amcoat.no) is a Norwegian paint company producing and marketing next generation marine coating with CNTs using a new unique patented technology. BIOCYL™ is Nanocyl’s (www.nanocyl.com) trade name for a range of eco-friendly, fouling release paints designed for all major marine coating applications, such as ship hulls, oil rigs, and underwater intake valves.
Hempel’s (www.hempel.com) anti-fouling products, Globic 9000 and Globic 6000 are designed around patented nano-capsule binder technology. The nanocapsule acrylate copolymers are the main binder which in combination with a powerful bioactive mixture makes it suitable for protection on vessels operating in aggressive fouling waters.
Wetted surfaces coated with the Inframat Corporation’s (www.inframat.com) product on naval vessels that were coated with this material approximately five years ago still show virtually no signs of biofouling. NanoCover A/S (www.nanocover.dk) products include marine seals and marine glass. Nanogate Technologies GmbH has developed a non-toxic surface coating, Nano® FPU to ensure a biofouling-free ship’s hull.
Nanovere Technologies, Inc. (www.nanovere.com) specializes in the development of clear coatings ultra-scratch resistant and self-cleaning paint that can be applied to marine paint. Tesla NanoCoatings (www.teslanano.com) supplies corrosion control coatings incorporating carbon nanotubes for marine markets. Diamon-Fusion International, Inc. (www.diamonfusion.com) develops nanocoatings with water and oil repellency (hydrophobic and oleophobic) for marine glass.
PURETi (www.pureti.com) produces a water based solution that air dries to form an invisible, well adhered, ultra thin, long lasting coating that actively protects all surfaces to which it is applied from the buildup of any organic matter – including bio-film, bacteria, molds or fungi. PURETi products can be applied to virtually any surface, including buildings, signs, solar panels, sidewalks, outdoor furniture, holding tanks, boats, and planes. Reactive Surfaces (www.reactivesurfaces.com) develop exterior marine coatings functionalized with bio-based additives for submersed hull surfaces and stationary structures.