Strategies for the development of marine antifouling coatings

Submerged surfaces in the marine environment are rapidly colonized by microscopic (bacteria, microalgae) and macroscopic (macroalgae, invertebrates) organisms. This diverse community is known as "biofouling". The harmful effects of this undesirable accumulation of organisms are now well known: increased boat weight and fuel consumption, bio-corrosion, introduction of invasive species...

Combating the development of these biofouling agents is a crucial issue from both a socio-economic and regulatory point of view. The solutions proposed are all based on limiting the adhesion of marine organisms, although the physico-chemical strategies and principles vary. Two main types of coating are marketed.

The first strategy is based on a chemical effect involving the release of biocidal molecules designed to eliminate organisms attempting to adhere. These coatings, commonly known as "antifouling paint", are now being called into question in the interests of preserving the natural environment. The development of these coatings has a significant regulatory dimension.

The second strategy proposes a surface that is inhospitable to the adhesion of marine organisms. The effect is based on the physical properties of the surface. These "non-stick" coatings are called "Fouling Release Coatings".

However, none of the solutions currently proposed are fully satisfactory (toxicity, loss of activity over time, difficult to use, etc.). In 2020, university and industrial research teams are turning to new strategies to offer solutions that are effective over time while respecting the environment. For this, nature is a real inspiration, enabling us to evaluate new avenues and propose new antifouling surfaces, which will be presented in this article.