Polyelectrolyte-fluorosurfactant complex-based meshes with superhydrophilicity and superoleophobicity for oil/water separation

To develop novel interface materials for oil/water separation, we describe a simple method to fabricate polyelectrolyte-fluorosurfactant complex-based meshes with superhydrophilicity and superoleophobicity both in air and underwater. The micro/nano-textured surface morphology, along with the interaction of hydrophilic groups and fluorinated alkyl chains, results in simultaneous superhydrophilicity and superoleophobicity. A water droplet can spread over the mesh surface with the contact angle of 0°, while a hexadecane droplet can roll off the mesh easily both in air and underwater. During oil/water separation process, water passed quickly through the mesh by the driving force of gravity and oils were retained above the mesh. As a result, various oil/water mixtures were separated using the mesh with the efficiency above 99.0%. Moreover, the performance stability of the prepared mesh was investigated using air plasma and corrosive aqueous solutions. After treatment, the mesh can keep the superhydrophilicity, superoleophobicity, and high oil/water separation efficiency. Therefore, this superhydrophilic and superoleophobic mesh would be a good candidate for oil/water separation to meet emerging needs in practical applications.