Fabrication of 3D porous materials with underliquid dual superlyophobic properties for oil–water emulsion separation and Cu2+ adsorption

Multifunctional materials for the simultaneous separation of oil-in-water or water-in-oil emulsions and adsorption of heavy metal ions are urgently needed for treating industrial wastewater with complex composition; however, at present these materials are strictly limited to a single function. To meet the above demand, a 3D polystyrene–divinylbenzene–trimethylolpropane triacrylate/polyethyleneimine (P(St-D-T)/PEI20) porous material with underliquid dual superlyophobicity was designed and prepared by the high internal phase emulsion polymerization one-pot method. Based on a structural design strategy involving the combination of hydrophilic and hydrophobic segments, hydrophilic and cationic PEI components were chemically grafted onto the surface of the hydrophobic P(St-D-T) porous material through a 1,4-conjugate addition reaction, endowing the material with underliquid dual superlyophobicity and metal ion-chelating coordination groups. The as-prepared material could continuously separate surfactant-stabilized oil-in-water and water-in-oil emulsions, with corresponding separation efficiencies of 99.4 % and 97.4 %, along with separation fluxes of 2543 and 8363 L m-2h−1 bar−1, respectively. The material also possessed excellent mechanical stability and outstanding chemical corrosion resistance. Furthermore, the P(St-D-T)/PEI20 porous material could adsorb Cu2+ in water through metal ion chelation, with a maximum adsorption capacity of 190.2 mg/g. This study provides a new approach to prepare a porous material with underliquid dual superlyophobicity for the treatment of complex oily wastewater.