Preparation and applications of 4-methyl imidazole magnetic surface molecularly imprinted polymers

Abstract

The magnetic surface molecularly imprinted polymers (MIPs) with specific recognition of 4-methyl imidazole (4-MI) were prepared by using 4-MI as template molecule, methacrylic acid (MAA) as functional monomer and Fe3O4 as magnetic fluid. The polymers were characterized by of Fourier transform infrared spectrometer (FT-IR) analysis, X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The results demonstrated that an imprinted polymer layer was successfully coated onto the surface of modified Fe3O4 nanomaterials, resulting in a narrow diameter distribution and good magnetic responsibility. The ultraviolet (UV) spectrophotometry was used to demonstrate the interaction between 4-MI and MAA. It was found that one 4-MI molecule was entrapped by one MAA molecule, which was the main existing form of subject and object. By UV spectrophotometric method to study the adsorption performance of magnetic molecularly imprinted polymers, the specific adsorption equilibrium and selectivity were evaluated by batch rebinding studies. The Scatchard analysis showed that there were two kinds of binding sites in the Fe3O4 @ (4-MI-MIP). The corresponding maximum adsorption capacities of 4-MI onto Fe3O4 @ (4-MI-MIP) were 40.31 mg/g and 23.07 mg/g, and the dissociation constants were 64.85 mg/L and 30.41 mg/L, respectively. The kinetic experimental data were correlated with second-order kinetic model. The magnetic molecularly imprinted polymers were used for the adsorption of 4-methyl imidazole in environmental water samples, and good results were obtained.