Bioinspired PDMS-Phosphor-Silicone Rubber Sandwich-Structure Coatings for Combating Biofouling

Inspired by the antifouling strategies of fluorescent corals and Gulf parrotfish, a novel polydimethylsiloxane (PDMS)-phosphor-silicone rubber sandwich-structure coating is fabricated for combating biofouling. The coatings can emit weak light during night hours and have hydrophilic surfaces. The effectiveness of the coatings against various algae and bacteria, namely, Chlorella, Nitzschia closterium f. minutissima, gram-negative Paracoccus pantotrophus, and gram-positive Bacillus subtili is investigated. The results show that the PDMS-phosphor-silicone rubber sandwich-structure coatings have broad-spectrum antifouling performances. The results also demonstrate that surface hydrophilicity can effectively reduce adhesion of algae and bacteria, and that fluorescence inhibits only algae. In addition, the effect is revealed of the wavelength of different colored phosphor layers on antifouling capability to resist Chlorella and N. closterium f. minutissima. Blue (427 nm), yellow (663 nm), and red (731 nm) phosphor layers are conducive to combating Chlorella and N. closterium f. minutissima, whereas the green (512 nm) phosphor layer shows no distinct effect on resisting Chlorella and N. closterium f. minutissima. These findings can contribute to the development of new antifouling coatings. In addition, the antifouling capabilities of these coatings have potential for further improvement and development. The sandwich-structure materials fabricated in this study should prove very useful in practical applications.