Fabrication of polydimethylsiloxane-attached solid slippery surface with high underwater transparency towards the antifouling of optical window for marine instruments

Marine optical instruments are commonly suffering serious biofouling problem caused by the adhesion of marine microorganisms, which severely affects the instruments to monitor the marine environment. Herein, we developed a robust solid slippery surface (SSS) by fabricated a covalently attached polydimethylsiloxane (PDMS) layer on glass substrate to solve the biofouling problem of marine optical instrument windows. The SSS could effectively inhibit the settlements of marine microorganism (bacteria and alga) in various environmental conditions, resulting from the high flexibility of PDMS molecular chains, and thus could maintain its high underwater-transparency. The antifouling mechanism of SSS was results from the weak nonspecific electrostatic Lifshitz-van der Waals forces and less specific hydrogen bonds between SSS and microorganism, which was been confirmed via both single bacterial force spectroscopy measurement and molecular dynamics simulation. Compared with the traditional slippery lubricant-infused porous surface (SLIPS), the SSS exhibited a better robust mechanical stability than that of the SLIPS. In addition, our study provides a valuable method to fabricated the SSS with reliable underwater-transmittance and antifouling properties, which is promised for the applications for the antifouling of marine optical instruments.