Synthesis of molecularly imprinted polymer on magnetic core-shell silica nanoparticles for recognition of Congo Red

Abstract

The extraction of Congo red from aqueous media is reported by a synthesized magnetic molecularly imprinted polymer. This polymer was prepared by coating of synthesized molecularly imprinted polymer on pre-prepared amino-modified Fe3O4 nanoparticles (Fe3O4@NH2-SiO2) surface. Coating process was done through the chemical coprecipitation method by use of acrylamide as functional monomer, N, N' methylenebisacrylamid as cross-linking agent, ammonium persulfate as initiator and N, N, N', N'-tetramethylethylenediamine as co-initiator in the presence of Congo red. The polymer was characterized by Field emission scanning electron microscope, Fourier transform infrared spectrometer, vibrating sample magnetometer, X-ray diffraction, and re-binding experiments. In addition, more investigations were performed including isotherms, adsorption kinetics, competitive adsorption and reusability. The results proved the sensitivity of the prepared polymer toward magnetic field. Accordingly, it can be easily removed by an external magnet. It demonstrated effective recognition selectivity as well as ability to simultaneous separation and enrichment of Congo red.