Graphene Coatings: Sustainable Antifouling for Marine Surfaces

Marine biofouling remains one of the most persistent cost drivers in the shipping and offshore industries, as the accumulation of microorganisms and algae on submerged surfaces increases drag and raises fuel consumption. For decades, the leading industry response has been to apply antifouling coatings based on toxic biocides. While these have been relatively effective, there has been growing regulatory pressure to lower environmental damage.

“The traditional way to remove fouling is to use toxic biocides,” notes Michael Kelly from the Norwegian University of Science and Technology. “However, this has a negative impact on the environment, and we should therefore limit their use.”

Now nanotechnology research is pointing to an affordable, yet more sustainable alternative in graphene‑based polymer coatings.

Kelly is a material science expert and has conducted extensive research into how nanomaterials can solve real-world industrial problems. In this instance, his studies analysed how mixing graphene, graphene oxide, and metal oxide nanoparticles with epoxy and silicone could “prevent fouling and the formation of biofilm both in the laboratory and in the sea.”

Graphene offers an interesting pathway, as it is a single‑atom‑thick layer of carbon arranged in a hexagonal lattice which combines exceptional mechanical strength, chemical stability, and barrier properties. When incorporated into polymer matrices such as epoxy or silicone systems, graphene and graphene‑oxide nanoparticles form advanced nanocomposite coatings which reduce the ability of microorganisms to attach and form stable biofilms on surfaces.

And while traditional biocidal coatings continuously release active substances into surrounding waters, contributing to long‑term ecological damage, graphene‑based systems aim to be non‑toxic. This they achieve through physical and surface‑chemical mechanisms rather than chemical release—an approach which aligns well with rising environmental standards and the risk of future regulatory bans on specific biocides.

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“The findings show that graphene nanomaterials prevent fouling not primarily by being chemically toxic, but by physically damaging cells upon contact with the material,” Kelly declares. Adding that, “The graphene coating is both durable and less toxic than biocides, while also acting as an anti-fouling agent.”

From a performance perspective, graphene‑enhanced coatings show several advantages over conventional systems. Not only do they avoid the need to poison marine organisms, but the graphene also improves hardness and abrasion resistance, extending a coating’s lifetime, even in harsh environments. The barrier properties of the nanocomposite also limit water and oxygen penetration, which can indirectly reduce corrosion of the underlying substrate.

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

From a commercial standpoint, life‑cycle economics are key. While graphene materials are still more expensive than conventional fillers, the overall cost balance favours the use of nanotechnology when durability and fuel savings are considered. Reduced drag lowers fuel consumption and the longer durability of a nanocoating reduces material use and labour costs associated with frequent recoating.

Beyond shipping, the market potential extends to offshore wind foundations, aquaculture installations, and underwater sensors, where biofouling similarly affects performance and maintenance costs.

While for coating manufacturers and raw‑material suppliers, graphene nanocomposites represent an opportunity to differentiate products in a market increasingly shaped by sustainability criteria rather than upfront price alone.

But perhaps most importantly, is that the use of nanotechnology in coatings is continuing to find ways to provide better protection with reduced environmental damage. In a world where a product’s “green qualities” are in as much demand as improved performance, a nano-coating which provides both will hold a clear market advantage.

Photo credit: Freepik, Picryl, & Satish Dharmavarapu on Unsplash