Zwitterionic polymer coatings with TMAO-based hydrated protective layers for marine anti-fouling and corrosion...

Marine biofouling and corrosion remain major challenges for ships and offshore infrastructure, increasing maintenance costs and reducing operational efficiency. However, biofouling in marine environments can have detrimental effects on materials. Amphiphilic coatings, which combine hydrophobic and hydrophilic properties, represent a promising class of anti-fouling materials. These coatings can reduce organism-surface interactions and suppress bioadhesion through the formation of a hydration layer. To achieve long-term and stable anti-fouling performance, we designed and fabricated an amphiphilic coating with a dual-network cross-linked structure (HPTE). By incorporating TMAO, an amphiphilic component that strongly interacts with water, the coating constructs a hydrated protective film on its surface. This layer protects the substrate from corrosion and damage induced by marine pollutants. The densely interwoven structure, enabled by abundant cross-linking sites, endows the coating with a high Young's modulus (1 GPa), excellent adhesion strength (∼4.81 MPa), and outstanding durability (withstanding 500 cycles of cotton abrasion). In a 20-day diatom adhesion test, the adhesion rate of chlorella on HPTE was only 51.2 cells per mm². This study provides a promising strategy for developing environmentally friendly and highly efficient anti-fouling coatings for marine applications.