A facile hydrophilic modification strategy initiated by flame treatment of silicone coatings for marine antifouling application

Non-toxic poly(dimethylsiloxane) (PDMS) elastomer antifouling coatings are used to protect marine equipment from biofouling; however, the coatings cannot resist all fouling organisms. Hydrophilic modification is an effective way to enhance antifouling performances in PDMS but most modification methods are complex and inconvenient. In this work, flame treatment was used to replace other complex surface activation techniques, such as plasmas. The sulfobetaine silane and polyvinyl alcohol (PVA) modifications were developed for flame treatment. The sulfobetaine silane-modified flame-treated PDMS reduced diatom adhesion by 99.0% compared to untreated PDMS. The PVA modification involves a two-step spray process and is simpler than sulfobetaine silane modification. This strategy coats PVA on flame-treated PDMS through the crosslinking effect of boric acid on PVA, which reduced diatom adhesion by 86.6% in the lab and gave better antifouling performances in field tests compare to bare PDMS.