Zwitterionic modified electrostatic flocking surfaces for diatoms and mussels resistance.

Environmentally friendly antifouling coatings without biocide release need to be developed. Herein, a vertical array of nylon fibers coated with poly(sulfobetaine methacrylate) (PSBMA) was prepared by the electrostatic flocking technique and free radical polymerization catalyzed by Fe2+, which are called zwitterionic electrostatic flocking surfaces (ZEFS). The ZEFS showed resistance to diatoms because the fiber diameter was smaller than the diatom size. At the same time, the ZEFS prevented mussels adhesion. The number of plaques on the ZEFS was reduced by more than 98% and 96% compared with the glass surface and polydimethylsiloxane (PDMS) after a 4-day assay. The special surface morphology of the vertical arrangement of fibers makes it difficult for the mussels to empty seawater. Zwitterionic surface modification further enhanced the resistance to mussel adhesion. The ZEFS showed strong hydrophilicity with an underwater oil contact angle of up to 152 ± 2.4°, which reduces the adhesion work of mussel protein adhesion to the fibers and the wettability of the protein on the fiber surface. In addition, the zwitterionic layer exhibited good stability in artificial seawater, and it retained more than 96% stability after 30 days immersion in artificial seawater.