An Ion-Imprinted Microporous Polypropylene Membrane for the Selective Removal of Cu(II) from an Aqueous Solution

An ion-imprinted microporous polypropylene membrane for the selective removal of Cu(II) from an aqueous solution was successfully prepared by combining graft polymerization with chemical modification. The chemical and physical changes of the ion-imprinted membranes surface were characterized by Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (FESEM-EDX), and water contact angle (WCA). The adsorption behaviors of the ion-imprinted membranes towards Cu(II) were investigated in detail using batch experiments. The equilibrium was achieved in approximately 60 min, and the experimental kinetic data fitted the pseudo second-order model better. The maximum adsorption capacity was 183.49 mu g/cm(2), and the Langmuir equation fitted the adsorption isotherm data. The results of competitive adsorption experiments indicated that the ion-imprinted membranes had high selectivity towards Cu(II), and the selectivity coefficients with respect to Zn(II), Ni(II) and Pb(II) were 60.40, 68.80, and 70.64, respectively. Permeation experiments showed that the ion-imprinted membranes exhibited good permeability and permselectivity towards Cu(II). Furthermore, the ion-imprinted membranes could maintain almost the same adsorption capacity towards Cu(II) even after ten adsorption-desorption cycles.