Developments and Challenges of Hydrogel Coatings for Long-Term Marine Antifouling Applications

As a result of the accumulation of marine organisms on submerged surfaces, marine fouling can have significant economic and environmental impacts. For example, marine fouling can increase drag and reduce the hydrodynamic efficiency of a vessel, leading to increased fuel consumption and operational costs as well as higher greenhouse gas emissions. The marine organisms attached to submerged surfaces can also induce corrosion and cause the marine structural integrity of the affected surfaces compromised, leading to increased maintenance and repair costs. Additionally, marine fouling can also pose biosecurity risks by spreading invasive species to new regions and disrupting local ecosystems. Great efforts have been made to develop effective and environmentally friendly antifouling technologies to mitigate these impacts. Hydrogel antifouling coatings have been proven effective and environmentally friendly, making them promising for practical marine applications. Here, brief overviews of antifouling mechanisms and types of hydrogel coatings are presented first. The latest developments in hydrogel antifouling coatings are categorized based on design strategies, and the limitations of these coatings are also critically appreciated with regard to their potential for practical marine applications. Finally, insightful perspectives on hydrogel coating are summarized for their use in practical marine applications.