LAUSR

Abstract A novel lead (Pb) ion imprinted polymers (IIPs) based on multi-walled carbon nanotubes (MWCNTs) were synthesized in inverse emulsion system, using N-isopropyl acrylamide (NIPAM) as the thermo-sensitive monomers, Methyl methacrylate (MMA) as the comonomer monomer and Pb(Ⅱ) as the template ion. The chemical structure and surface topography of IIPs were characterized by Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), thermogravimetry (TG) and scanning electron microscopy (SEM). The adsorption properties of ion imprinted polymers were investigated by atomic absorption spectrophotometry (AAS). The results showed that the adsorption and desorption efficiency of imprinted polymers could be controlled by changing the temperature. Under the optimal adsorption temperature of 45 ℃, the maximum adsorption for Pb2+ by IIPs was 18.09 mg/g. The adsorption process conforms the thermodynamic Langmuir model and pseudo second-order kinetic isotherms, the desorption efficiency at 25 ℃ was much greater than that at 50 ℃. When the competitive Cu2+, Cd2+, Zn2+ and Ni2+ were present, the selection coefficients of Pb2+/Cu2+, Pb2+/Cd2+, Pb2+/Zn2+ and Pb2+/Ni2+ were 20.61, 24.15, 24.20 and 27.57, respectively, indicating that IIPs had strong recognition ability for Pb2+. The electrochemical properties of ion-imprinted carbon paste electrodes (CPE/IIPs) were investigated by cyclic voltammetry (CV). Studies had shown that CPE/IIPs had excellent electrochemical properties, which laid the foundation for future electrochemical research.