Preparation and evaluation of magnetic molecularly imprinted polymers based on konjac glucomannan for urea

Magnetic molecularly imprinted polymers (MIPs) for urea were prepared using konjac glucomannan (KGM) as the substrate, methacrylic acid as the graft comonomer, ethylene glycol dimethacrylate as the cross-linker, urea as the template molecule, and Fe 3 O 4 NPs as the magnetic ingredient. The resultant MIPs were characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, vibrating sample magnetometry, and Brunauer–Emmett–Teller spectroscopy. The MIPs possessed high superparamagnetism with core–shell structures, which could be easily separated from the mixture by an external magnetic field. The MIPs could specifically recognize urea, and the recognition capacity and adsorption performance remained almost unchanged after three cycles of adsorption and elution. The adsorption kinetics of MIPs on urea could be described by the second-order kinetic model. The maximum adsorption capacity of MIPs on urea was 16.80 mg/g, and the adsorption isotherms of MIPs on urea followed the Langmuir model. In addition, in vitro adsorption experiments through simulated body fluids showed that the MIPs had good adsorption capacity for urea. The product is expected to be used as a novel adsorption material for blood purification.