Fig. 3

a Schematic description of the preparation of polydopamine (PDA) coated stainless steel mesh film and N-dodecyl mercaptan (NDM) modified surface through Michael addition reaction [14]. b The low-magnification view of the PDA–NDM mesh with an average diameter [14] of approximately 40 μm [14]. c The photograph of a water droplet (2 μL) on the PDA–NDM mesh with a contact angle of 143.8 ± 1.0° [14]. d A diesel oil droplet (2 μL) spreads and permeates quickly on the mesh [14]