Adhesion of micro-organisms on hulls, algae to the coated surface, is the precursor of later fixation of macro-organisms, which causes serious hydrodynamic problems.
Research and innovative developments of environmental friendly surface protection is the main goal of the present project.
The basic idea concerns the modification of usual hulls by providing anew antifouling coating, by fixing covalently bioactive molecules, whichcan provide biocide activity, in order to avoid leaching and to promotea long-term effect of surface protection. This requires the bindingthrough a molecular bridge and to study the effective concentration ofthe binded active compounds. The new surface coating technology will bythis way minimize the surface roughness and improve hydrodynamicproperties of hulls.
Innovative coatings to combat biofouling
Marine biofouling is a well-known problem involving adhesion and growth of macro- and microorganisms on water-immersed surfaces that can pose a significant impediment to ship performance. EU-funded researchers developed environmentally safe biofouling prevention coatings that can also find use in bridges and other inland metallic structures in coastal areas and wet zones.
Fouling of ship hulls can reduce a vessel's speed, requiring a large increase in fuel consumption to counter the added drag. Increasing the hull roughness only by 50 μm can raise fuel expenditure by 50 %. The International Maritime Organization (IMO) estimated that carbon dioxide emissions associated with fuel consumption from shipping could increase more than twice by 2030.
Within http://www.foulxspel-antifouling.com/ (FOUL-X-SPEL) (Environmentally friendly antifouling technology to optimise the energy efficiency of ships), researchers investigated environmentally friendly coatings for ship hulls to prevent biofouling organisms from interfering with a ship's hydrodynamic performance. Previous biofouling solutions included use of toxic biocides that beyond killing organisms trying to attach to the hull also posed a threat to the wider aquatic ecosystem. Hitherto solutions based on biocide-free formulations proved to be inefficient in preventing aquatic attachment.
FOUL-X-SPEL research yielded significant progress in the development of two powerful, non-toxic protective coatings. The first one was a polyurethane-based paint containing two immobilised biocides (Econea and Irgarol), and the second one a silicone-based formulation containing immobilised Econea.
Researchers provided novel antifouling coating technology by fixing bioactive molecules (biocides) in the coating matrix to eliminate biocide discharge into the surrounding environment and also ensure long-term surface protection. The new coatings present very low friction with water and keep the vessel free from fouling for up to 90 months. In addition, they minimise the surface roughness and improve hull hydrodynamic properties.
By reducing microorganism build-up, the newly developed coatings can substantially improve ship performance and fuel efficiency, while dramatically cutting hull maintenance costs. Furthermore, they can reduce the transport of invasive species via ship hulls.