Magnetic Interconnected Macroporous Imprinted Foams for Selective Recognition and Adsorptive Removal of Phenolic Pollution from Water

Here, novel magnetic imprinted porous foams (MIFs) were prepared by Pickering oil-in-water high internal phase emulsion polymerization, using renewable cellulose nanocrystals (CNCs) derived from cotton source as the stabilizer, and surfactant Tween 85 and iron oxide magnetic nanoparticles as additive in aqueous phase, for selective adsorption of 4-nitrophenol (4-NP). Interconnected porous foam structure was formed and optimized by controlling the addition amount of solid stabilizer CNCs, Tween 85, and oil phase volume, the optimum value of which was 7.5 wt%, 5.0 wt%, and 85 %, respectively. The as-synthesized imprinted material had the good thermal stability and magnetic responsivity. The adsorption equilibrium data was fitted well by the Langmuir isothermal model with a maximum adsorption capacity of 287.5 µmol/g. Pseudo-second-order kinetics model could better describe the kinetics data. MIFs showed excellent selective ability for 4-NP as compared with these structural analogues. Besides, Thomas model explained the dynamic breakthrough curves better. The regeneration ability of MIFs was also satisfying after several reuse.