Kiel University researchers have developed an environmentally-friendly coating that rids ship hulls of marine organisms such as barnacles, algae and shells.
It is a known fact that barnacles quickly overgrow ship hulls and attack their lacquer coating as part of a process called ‘biofouling.’ This in turn increases the weight of the ship and its flow resistance, causing a surge in fuel consumption and higher CO2 emissions.
Now a research team from the Christian-Albrechts-Universität zu Kiel (CAU) and the Phi-Stone AG, a spin-off of the CAU based in Kiel, has developed a coating that not only impedes the colonization of marine organisms but also makes it easier to clean ships.
“We assume that biofouling increases the fuel consumption of ships by up to 40 percent. That costs the transportation industry over $150 billion a year worldwide and unnecessarily pollutes the environment, “says Ingo Paulowicz, CEO of CAU spin-off Phi-Stone.
In addition, there is a considerable cleaning and maintenance effort to free the hulls of barnacles and other adhering organisms and repaint them again. Many of the existing protective coatings like organotin paints are already banned because of their massive environmental impact.
The newly developed coating is said to combine environmental friendliness with durability. The product is solvent-free and does not release any polluting substances into the sea.
Moreover, the smooth surface of the coating makes it difficult for organisms to cling to the hulls and attack the coating. “This way, the biocorrelation-resistant paint is preserved for a longer time, and barnacles or shells can be brushed off easily and quickly,” explains Dr Martina Baum, Technical Biologist from the working group Functional Nanomaterials.
Together with her former doctoral student, materials scientist Iris Hölken, Baum investigated the soil-reducing properties of a polymer composite based on polythiourethane (PTU) and specially shaped ceramic particles. They improve the mechanical properties of the coating and the adhesion of the paint to the ship’s surface.
The researchers first tested the new product with Schleswig-Holstein companies in the water basins of the GEOMAR Helmholtz Center for Ocean Research Kiel and on ships.
“These tests went very well,” says Baum. “On the ‘African Forest’, which runs from Belgium to Gabon in Central Africa, we were able to detect significantly less fouling after two years with the coating. And he just got away with a sponge. ”
Image credits and content: Dr. med. Martina tree/Christian-Albrechts-Universität zu Kiel (CAU)