Fabrication of deep eutectic solvent-molecularly imprinted polymer in water: A green strategy for adsorption of bisphenol A

Abstract

Molecularly imprinted polymers (MIPs) have been widely used in the field of environmental engineering, but the traditional MIPs are still not green because large quantities of organic porogen and hazardous functional monomers are required during the preparation process. To overcome these challenges, the green deep eutectic solvent (DES) and water were separately used as functional monomer and porogen to prepare molecularly imprinted polymer (MIP). Herein, the multiple functional groups on DES can form various forces with the target (bisphenol A, BPA) resisting the interference of water molecules. Characterization showed MIP had rough surface and rich functional groups. Results of batch experiments demonstrated that the MIP had a maximum adsorption capacity of 110.15 mg g−1 toward BPA from water and the Freundlich isotherm and pseudo-second-order kinetic models were suitable for analyzing the BPA adsorption process. Results of fixed-bed column illustrated that the breakthrough time prolonged with the adsorbent mass increasing, while forwarded with the BPA inlet concentration and flow rate increasing. Both Thomas and Yoon Nelson models could effectively describe fixed-bed adsorption. Additionally, the MIP was used as a pretreatment column adsorbent in combination with HPLC for the determination of BPA in eight environmental samples with satisfactory recoveries (91.02–108.20%). And the selective recognition mechanism of MIP for BPA was due to the combination of imprinting effect, hydrogen bonding and π-π stacking. In this work, a promising way has been developed to prepare green MIP for the selective adsorption of BPA in the field of environmental chemical engineering.