Preparation And Absorption Properties Of Ion-Imprinted Materials Based On Carbon Nanotubes

Carbon nanotube-based ion imprinting materials have selective adsorption for targeted metal ions.By such adsorption,heavy metal ions in environment can be removed and recycled effectively.With magnetic carbon nanotubes as base materials,Ni2+ as templates,chitosan,acrylic acid and N-isopropyl acrylamide as functional monomers,two new ion imprinting materials,IPPs-1 and IPPs-2,were prepared.1)The structural properties of IPPs-1 and ?Ps-2 were characterized by Fourier transform infrared spectroscopy,X-ray diffractometer,field emission scanning electron microscopy and thermal integrated analyzer.It showed magnetic Fe3O4 particles were loaded onto the surface of carbon nanotubes,imprinting polymers were modified onto the surface and excellent thermostability was possessed by both ?Ps-1 and ?Ps-2.2)The adsorption properties and mechanisms of ?Ps-1 and ?Ps-2 were checked by flame atomic absorption spectrophotometer.The results showed,for ?Ps-1,equilibrium absorption capacity was 19.86 mg/g;optimum p H of adsorption solution was 6;saturated adsorption capacity remained almost unchanged after five cyclic adsorptions;adsorption process matched second-order kinetics and Freundlich thermodynamic adsorption models.For ?Ps-2,the results indicated equilibrium absorption capacity was 24.06 mg/g;optimum p H of adsorption solution was 6;saturated adsorption capacity declined slightly after four cyclic adsorptions;adsorption process matched second-order kinetics and Freundlich thermodynamic adsorption models.Good selective adsorption of ?Ps-1 and ?Ps-2 for Ni2+ can be seen while competing ions Pb2+ and Cu2+ coexisted in solutions.3)The prepared ?Ps-1 and ?Ps-2 were preliminarily studied in electrochemistry.Electrochemical responses of CPE/?Ps-1 and CPE/?Ps-2 in base solutions with Ni2+ were tested via cyclic voltammetry.It indicated that the redox peaks appeared on cyclic voltammetry curve of the two modified carbon paste electrodes towards Ni2+ in solutions,indicating the potentials for Ni2+ detection of the two modified carbon paste electrodes.