Self-repairing silicone coatings for marine anti-biofouling

Marine biofouling is one of the most challenging problems today. Silicone polymer based coatings with a low surface energy and elastic modulus can effectively inhibit or release biofouling. However, their non-repairable properties and poor antifouling ability under static conditions limit their applications. Here, we report a self-repairing coating consisting of poly(dimethylsiloxane) based polyurea (PDMS-PUa) and a small amount of organic antifoulant (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) (DCOIT). The coating can completely recover its mechanical properties after damage either in air or artificial seawater at room temperature. Such recovery can be accelerated at a higher temperature. Moreover, the release rate of DCOIT is almost constant and can be regulated by its concentration. Six-month marine field tests demonstrate that the system has a good antifouling/fouling release performance even under static conditions.