Rare earth oxide nanoparticles for superhydrophobic, antifouling and self-cleaning coatings

The widely used rare earth oxides (REOs) have a limited application in antifouling coatings. Here, coatings composited with REOs-1H,1H,2H,2H-perfluorodecytrimeth-oxysilane (REOs-FAS) based on hydrothermal reaction were prepared for study if REOs can be used in marine antifouling coatings. A network consisting of polydimethylsiloxane (PDMS) and REOs-FAS (REOs-FAS/PDMS) (RE = Ce, Pr, Nd) was created by using the blending method and polymerization reaction. The presence of the REOs-FAS imparts to the polymers an amphiphobic structure and disrupts the cell membrane, resulting in excellent antifouling properties and antibacterial performance. The water, coffee, and soya-bean milk droplet state on the Pr₆O₁₁-FAS/Sylgard 184 silicone elastomer with the ratio of 4:1 (PFSR-4) and the ink self-cleaning experiment demonstrated that the PFSR-4 has a perfect self-cleaning property. The most suitable surface roughness of PFSR-4 not only empowered the superhydrophobic (the contact angle of water is as high as 157° ± 2° and the sliding angle of water is as low as 5° ± 2°)-oleophobic characteristic (the contact angle of diiodomethane is as high as 132° ± 3°), but also endowed the coating with the anti-diatom (as high as 97.7 %) and anti-mussel adhesive properties. Moreover, the colored PFSR coatings were prepared to do another barrier for the adhesion of large fouling organisms, especially for the white coatings. The anti-mussel attachment ratio of purely whited PDMS was high to 84.6 %. The antibacterial REOs are appropriate for preparing multi-functional coatings. In general, the designed coating has the potential to be a durable, self-cleaning, antibacterial, and antifouling coating and could serve as a foundation for developing innovative super-amphiphobic coatings.