Fifty years of the Baier curve: progress in understanding antifouling coatings

Biofouling is an entirely natural process, but when it affects ship hulls, it adversely affects society through increased fuel consumption and production of carbon dioxide (CO2). Today, marine coatings include toxicants such as copper that prevent fouling but can themselves harm the environment. The societal choice then is either to burn more fuel or to release toxicant. Researchers today are looking for solutions that minimize or eliminate toxicants yet are efficient enough in antifouling performance that additional fuel consumption is not required. Understanding and controlling the physical structure of a coating surface that interacts with its environment may lead to effective toxicant-free or toxicant-reduced antifouling coatings. This commentary describes several current approaches in terms of the Baier curve, the relationship between fouling release and surface energy, the mechanical properties of the coating, the kinds of materials that presently show the most promise and recently developed strategies for antifouling coating design.