Hull fouling is a problem familiar to most boat owners, and for the maritime industry, marine biofouling represents a significant challenge.

Biofouling consists of various living organisms that attach themselves to parts of boats below the waterline. These can include microorganisms, algae and shells. Fouling increases water resistance, fuel consumption and maintenance costs. Many owners commonly haul their boat out of the water once a year to clean the hull.

“The traditional way to remove fouling is to use toxic biocides. However, this has a negative impact on the environment, and we should therefore limit their use,” said Michael Kelly from the FACET research group at the Norwegian University of Science and Technology (NTNU’s) Department of Materials Science and Engineering.

Kelly’s recent doctoral thesis investigates a more environmentally friendly alternative. This alternative goes by the rather complicated name of ‘graphene-based polymer nanocomposite coatings’. Graphene is a material consisting of a single layer of carbon atoms.

“The graphene coating is both durable and less toxic than biocides, while also acting as an anti-fouling agent,” explained Kelly.

He studied the effect of mixing graphene, graphene oxide and metal oxide nanoparticles with epoxy and silicone. The aim is to establish how these materials can prevent fouling and the formation of biofilm both in the laboratory and in the sea.

“The findings show that graphene nanomaterials prevent fouling not primarily by being chemically toxic, but by physically damaging cells upon contact with the material,” explained Kelly.

He also investigated different epoxy blends and graphene oxide fillers to improve the coatings’ strength and durability.

“The results are promising in terms of developing effective coatings that protect both vessels and infrastructure with minimal environmental impact,” concluded Kelly.