Hierarchical porous molecule/ion imprinted polymers with double specific binding sites: Combination of Pickering HIPEs template and pore-filled strategy

Abstract

To recognize and remove targeted organic and inorganic pollutants simultaneously, a simple and outstanding approach was provided to fabricate hierarchical porous molecule/ion imprinted polymers (M-IIPs) with double specific binding sites, Firstly, λ-cyhalothrin (LC) molecules imprinted polymer foam initiators (MIPFIs) with the average void diameter of 8.0μm were prepared via a W/O Pickering high internal phase emulsions (HIPEs) template stabilized by vinyl-silica particles (V-SPs). Secondly, based on a pore-filled strategy, adjustable amounts of copper ions (Cu(II)) imprinted polymers (IIPs) were incorporated into the macroporous surface of MIPFIs via atom transfer free radical polymerization (ATRP). Owing to the well-defined hierarchical porous structure, M-IIPs possessed enhanced binding kinetics, and the maximum monolayer adsorption capacities of as-prepared M-IIPs were 193.1μmolg−1 and 169.9μmolg−1 towards LC and Cu(II), respectively. The imprinting factor ε was 1.942 for LC, while their relative selectivity coefficients αr for Cu(II)/Zn(II) and Cu(II)/Ni(II) were 6.31 and 4.24 times higher than those of non-imprinted polymers (N-NIPs), illustrating that M-IIPs showed excellent molecular recognition in testing solutions. In the binary solution of LC and Cu(II), an enhanced adsorption capacities towards LC and Cu(II) were observed, indicating the existence of promotion in selective adsorption ability in the case of coexistence of LC and Cu(II). Besides, test of reusability suggested that the M-IIPs could be repeatedly used without any significant loss in binding capacity. Overall, this work not only provided new insights into the fabrication of porous imprinted composites with huge specific surface area and binary function, but also highlighted their application for selective and simultaneous removal of LC and Cu(II).