Constructing Self-Renewing Silicone-Hydrogel Hybrid Coatings with Integrated Fouling Resistant/Release/Killing Mode toward Superior Biofouling Defense

Abstract

Silicone hydrogel coatings, which integrate fouling self-release and fouling resistant properties, represent a groundbreaking advancement in environmentally friendly biofouling mitigation, but are still plagued by static fouling conditions and longevity concerns. In this work, Schiff base chemistry and a sol-gel technique is leverage to develop degradable silicone-hydrogel hybrid antifouling coatings by incorporating amphiphilic silicone-based polymers with terephthalaldehyde (TPE) and cinnamaldehyde (CAL). The synergistic combination of flexible Si─O bonds in the polymer backbone and reversible covalent crosslinking imparts exceptional flexibility (hardness of 0.135), controlled degradability, and dynamic surface self-renewal capabilities, ensuring sustained antifouling performance through surface dynamic stability. During degradation, the amphiphilic polymers will self-enrich at the interface, forming a dual-functional surface that combines fouling release and fouling resists properties. The antibacterial TPE and natural CAL, anchored within the polymer network, exhibit environment-responsive release behavior, effectively suppressing bacterial proliferation and biofilm adhesion. The optimized coating achieves a bactericidal rate of 98.8%, an anti-bacterial adhesion rate of 99.8%, and a predicted anti-fouling longevity of 5.5 years with a thickness of 200 µm. This innovative approach enables a new anti-biofouling coating that involves unique fouling control mode, thereby meeting the diverse application.