Facile fabrication of self-healing silicone-based poly(urea-thiourea)/tannic acid composite for anti-biofouling

A novel silicone-based poly(urea-thiourea)/tannic acid composite (PDMS-P(Ua-TUa)-TA) with excellent mechanical, self-healing and antifouling properties is developed. The multiple dynamic hydrogen bonds formed by thiourea groups, urea groups, and tannic acid (TA) molecules ensured a tough elastomer (ultimate strength: 2.47 MPa) with high stretchability (-10 0 0%). TA molecules as partial hydrogen bonding cross-linking sites interacted rapidly with urea and thiourea groups before the migration of polymer chains, resulting in fast and efficient self-healing. Scratches on the film completely disappeared within 12 min, and the repair efficiency of strength was up to 98.4% within 3 h under ambient condition. Self healing behavior was also evaluated in artificial seawater and the healing efficiency (HE) was 95.1%. Furthermore, TA uniformly dispersed in the polymer matrix provides good antibacterial and anti-diatom properties, as well as strong adhesion to the substrate (-2.2 MPa). Laboratory bioassays against marine bacteria adhesion (-96%,-95% and-93% reduction for P. sp., E. coli, and S. aureus, respectively) and diatom attachment (-84% reduction) demonstrated an outstanding antifouling property of the PDMSP(Ua-TUa)-TA. This work provides a promising pathway towards the development of high-performance silicone-based coatings for marine anti-biofouling. (c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

A novel silicone-based poly(urea-thiourea)/tannic acid composite with excellent mechanical, self-healing, and antifouling properties has been developed. The material demonstrates outstanding antibacterial and anti-diatom properties, as well as strong adhesion to the substrate. It also exhibits fast and efficient self-healing, making it a promising candidate for high-performance marine anti-biofouling coatings.