Sustainable antifouling by controlled release from polymer bound SelektopeⓇ

Creating new ways to introduce polymer-bound active substances into marine antifouling coatings

Abstract

Biocide-containing antifouling coatings are widely used to prevent the accumulation of marine biofouling on vessel underwater surfaces. The adhesion of microbial slimes, macro algae and hard-shelled organisms such as barnacles on vessels create increased friction as the hull glides through the water. This can lead to reductions in vessel manoeuvrability, increased weight and reduced speed, all of which can result in increased fuel consumption and maintenance costs.

A study conducted by I-Tech and Safinah Group found that of 44% of the 249 large, ocean-going vessels inspected in dry dock had over 10% of their underwater hull surface covered with hard fouling. If you extrapolate that to global fleet scale, we estimate that based on added resistance due to hard fouling data published in study by Michael P. Schultz in 2011) just 10% hard fouling coverage could be responsible for at least 110 million tonnes of excess carbon emissions per year, and an additional US 6 billion spent annually on fuel from the international shipping industry.

As the first line of defence against biofouling, antifouling coatings must ensure continued protection, as biofouling conditions change and intensify in warming waters due to climate change.

Today, there are a limited number of biocides available for use in marine antifouling coatings. For these biocides, a sustainable release rate of across the entire intended lifespan of a coating product is essential for effective biofouling prevention. For example, antifouling coatings for large, merchant vessels need to deliver adequate antifouling protection for up to five years vessel operational time between dry docking, as dictated by safety obligations at an international level.