Fabrication and antifouling behavior research of self-healing lubricant impregnated films with dynamic surfaces

Strategy for Fabricating Degradable Low-Surface-Energy Cross-Linked Networks with Excellent Anti-Fouling Properties

Marine biofouling negatively impacts marine industries and ship navigation. However, current coatings are based on a single antifouling mechanism, which is insufficient to cope with the complex and ever-changing marine environment. Herein, multifunctional antifouling coatings were developed using a material system containing perfluoropolyether and caprolactone chains. First, an acrylic resin containing perfluoropolyether side chains was synthesized as a liquid-repellent component and then a degradable cross-linked network was constructed by bridging polycaprolactone chains. Surprisingly, polycaprolactone chains not only effectively improved the tensile strength but also provided flexibility to the resin. Thus, the coating exhibited satisfactory mechanical stability and low roughness (4.06 nm) during dynamic polishing. It is worth noting that the cross-linked network with a low surface energy (SE) (22.0 mJ·m-2) effectively inhibited the adhesion of marine fouling organisms. Moreover, the hydrolysis of ester groups promoted the formation of a self-renewing surface, and the synergistic effect of the low SE and degradability of the coating ensured excellent and long-lasting antifouling performance of the coating. The coating reduced the adhesions of Vibrio alginolyticus, Nitzschia sp., and Navicula sp. by 99.99, 84.6, and 91.0%, respectively, compared with their adhesions to a commercially available self-polishing coating (B3000). Thus, the degradable low-SE antifouling coating produced using the proposed strategy can be potentially applied to various maritime industries.

Amphiphilic Marine Antifouling Coatings Based on Zwitterion-Modified Silicone Polymers

Silicone coatings are widely employed in marine antifouling applications due to their low surface energy. However, in static marine environments, pure silicone coatings are ineffective in preventing the adhesion of marine biofilms, which consist of proteins, marine bacteria, and extracellular matrices, ultimately promoting the attachment of macrofouling organisms. To address the limitations in antifouling performance under static conditions, this study introduces a silicone-based antifouling coating modified with zwitterionic polymers. Sulfobetaine (SB) zwitterionic segments were grafted onto the side chains of poly(dimethylsiloxane) (PDMS) to synthesize the amphiphilic polymer P(DMS-SB), which was incorporated into the PDMS network to create an interpenetrating network-structured silicone coating. The zwitterionic segments effectively inhibited the adhesion of proteins, bacteria, and algae through hydration effects. Compared to pure PDMS coatings, the adhesion of proteins, bacteria, and algae was reduced by 88%, 98.9%, and 99.3%, respectively. Additionally, the coating demonstrated excellent fouling-release properties, achieving a 91.3% removal rate for settled algae under water flow conditions and reducing the simulated barnacle adhesion strength by 68.4%. This coating presents a promising antifouling solution for ships, offshore structures, and aquaculture facilities in static marine environments with significant potential for widespread application.