Fabrication and Characterization of Zwitterionic Coatings with Anti-oil and Anti-biofouling Activities

Underwater ultraoleophobic materials with superhydrophilic surfaces have great potential for several applications due to their anti-fouling, self-cleaning, oil/water separation, droplet manipulation, and drag reduction properties. In our research described here an underwater ultraoleophobic coating containing zwitterion carboxybetaine acrylamide (CBAA) was prepared using self-polymerization of dopamine (DA) and co-deposition of polydopamine (PDA) with zwitterionic poly(carboxybetaine acrylamide) (PCBAA) based on hydroxyl radical activation. The morphology of the coatings could be easily controlled by adjusting the initial ratio of dopamine/carboxybetaine acrylamide (DA/CBAA). The structures, surface morphologies and properties of the coatings so obtained were analyzed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurements. The polydopamine/poly(carboxybetaine acrylamide) (PDA/PCBAA) coatings exhibited excellent superhydrophilicity and underwater superoleophobicity with water contact angles (WCA) of 1.5° and underwater oleophobicity contact angles (OCA) of 160°. The anti-biofouling, oil-water separation, and mechanical stability properties for PDA/PCBAA co-deposited coating were comprehensively investigated. These interesting properties make the coatings promising candidates for numerous applications.