Market and Labs Rife with Antifouling News
With some biocides, like tributyltin, long banned in marine coatings and others subject to public scrutiny in recent years, the race to find effective antifouling agents without biocides has heated up in the research-and-development world.
Preventing biofouling is important for industry—which benefits in increased efficiency when resistance is decreased on a ship’s hull—and the environment, as hulls can transport invasive species throughout the world. But concerns over the lasting effects of biocides on small marine life have fueled the push for new alternatives.
A number of products that have come to market in recent months promise resistance to fouling without tin or copper—currently the most common biocide used in hull coatings—and many other novel approaches are in the pipeline.
New Biocide-Free Self-Polishing Copolymer
Nippon Paint Marine, part of the Osaka, Japan-based Nippon Paint, announced last week the release of what it calls the world’s first biocide-free, low-friction self-polishing copolymer antifouling coating line, Aquaterras, a copper-free and non-silicone-based coating.
Aquaterras, according to the company, is based on patented polymer technology that uses hydrophilic and hydrophobic microdomain structures and a hydrolysis reaction to resist biofouling. The line exhibits long-term, stable self-polishing, Nippon says, making it an effective tool against the friction resistance that can drag down fuel efficiencies in vessels.
The polymer is based on materials developed for use in medical devices like artificial hearts and blood vessels.
Historically, self-polishing copolymer coatings relied on tributyltin, but the new coating is tin-free while working off the same basic mechanism.
UV Light, Graphene, Nanostructures
Earlier this year, Dutch coatings firm AkzoNobel announced a development that sees the company working with Royal Philips on a coating that incorporates ultraviolet LEDs that would prevent organisms from growing on a surface like a ship’s hull or the submerged parts of offshore structures. That product is under development and has not been brought to market yet.
|© Lars Heepe|
A recently introduced silicone coating from Germany’s Kiel University utilizes “mushroom-shaped surface topography” to prevent barnacles from getting a foothold with the “cement” they use to attach to a surface.
Australian firm First Graphene Limited is currently working with Engage Marine (Perth) on coatings for marine use that would utilize graphene—the atom-thin carbon material—as an antifouling agent. The firm says marine paints enhanced with graphene could be more effective than antifouling coatings currently on the market, while potentially lasting longer, requiring a recoat only every five years instead of every three.
Some alternatives under development are effective against “macrofouling”—infestations with barnacles and other larger organisms. That includes a recently introduced silicone coating from Germany’s Kiel University, which utilizes “mushroom-shaped surface topography” to prevent barnacles from getting a foothold with the “cement” they use to attach to a surface.
Others, such as a nanomaterial developed at the University of Sydney and based on the surface topography of the pitcher plant, are made to address smaller organisms such as bacteria, which can form an initial biofilm that then leads to the growth of more organisms on a ship’s hull.