There is a demand for more sustainable antifouling coatings for ships. These innovative solutions should largely dispense with biocides while still withstanding the challenges of maritime use. Industry and science are working together to develop such environmentally friendly coatings. They are doing this as part of the "BioSHIP" project, funded by the German Federal Ministry for Economics and Climate Action (BMWK) under the "Maritime Research Programme."
With more than 30,000 square metres, the hull of a medium-sized container ship can reach impressive dimensions. These vast areas provide an ideal habitat for a variety of organisms such as algae, barnacles and mussels. However, this colonisation causes significant problems for shipping.
Disadvantages biological fouling
Fouling - biofouling - increases flow resistance and leads to higher fuel consumption. This not only leads to higher costs, but also contributes to an increase in carbon dioxide emissions. There is also a risk that introduced species will threaten the stability of marine ecosystems. Anti-fouling coatings containing biocides are usually used to combat biofouling. These are very effective coatings but often contain poorly degradable substances that have undesirable effects on water quality and aquatic organisms. Therefore, many different approaches have been taken over the past decades to develop more environmentally friendly coatings. Nevertheless, many self-shining coating systems are based on problematic salts of heavy metals that end up in water bodies and sediments.
From coatings with biocides to an eco-friendly alternative
Biocides currently dominate the market. The targeted release of heavy metals makes them particularly effective against biofouling. They account for about 80 per cent of the applications used worldwide. The most commonly used self-shining coatings also contain special polymers that break down on contact with water. In this way, they always create a smooth surface, making colonisation difficult.
The BioSHIP project
The aim of the "BioSHIP" project is to develop a biodegradable, self-shining marine coating that requires significantly lower levels of toxic heavy metals and minimises environmental pollution. A promising approach for biodegradable, self-polishing coatings lies in targeted control of the degradation rate to ensure a long-term antifouling effect. The project focuses on more sustainable formulations. These include the use of bio-based polymers such as polylactide (PLA) or chitosan derivatives, which degrade in a controlled manner under marine conditions without leaving harmful residues. The balance between sustainability and biodegradability can be further optimised by the targeted synthesis of functionalised additives.
Coated rudder blade: Despite the protective coating, barnacle growth occurs, whose chalky shells increase frictional resistance, increase fuel consumption and can interfere with rudder operation. (Photo: Fraunhofer IFAM)
Interdisciplinarity
The project combines expertise from different disciplines to ensure targeted development. Material development focuses on biodegradable polymers and innovative coating components that meet requirements for durability, protection against fouling and environmental friendliness. At the same time, the coatings are tested under real marine conditions, including different geographical regions, to ensure wide applicability. In addition, the project partners conduct ecotoxicological studies to ensure that the materials developed have no harmful effects on organisms.
Technological innovation
Through close collaboration between science and industry, the project shows how technological innovations can help address global challenges. The results of "BioSHIP" can not only make a valuable contribution to the maritime industry. They can also boost other sectors that depend on sustainable material solutions. Especially in regions with strict environmental legislation, such as Europe, Australia, New Zealand or parts of the US, the technology could set new standards and give a decisive impetus to the transition to more sustainable shipping.
Details of the project:
Funding: Ministry of Economic Affairs and Climate Action (BMWK)
Duration: 01/08/2024 - 31/01/2028
Project management organisation: Projektträger Jülich (PtJ)
Funding amount: 1.6 million
Project partners :
- Momentive Performance Materials GmbH (coordinator)
- Dr Brill + Partner GmbH (Institute for Antifouling and Biocorrosion, Norderney)
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM
- Hydrotox GmbH
Opening photo: Barnacles and dried-up biofilm are typical traces of marine fouling. (Photo: Fraunhofer IFAM)
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