Fast and efficient removal of copper using sandwich-like graphene oxide composite imprinted materials

Publication date: 15 October 2017
Source:Chemical Engineering Journal, Volume 326
Author(s): Delong Kong, Ning Qiao, Huan Liu, Jian Du, Nian Wang, Zhiyong Zhou, Zhongqi Ren
A sandwich-like ion-imprinted polymer (IIP) was prepared using functional graphene oxide (GO) as the support, acrylamide as the functional monomer, and ethylene glycol dimethacrylate as the crosslinking agent in the presence of copper ions with various solvents (porogen). The effect of solvent type on polymerization process and properties of polymers was investigated. Methanol/acetonitrile was considered as the best porogen, and almost no redundant secondary polymer particles were produced. This can be explained by the good thermodynamic compatibility and slow phase separation property of monomers and crosslinking agents in polymerization process. Fourier-transform infrared spectroscopy, Energy dispersive X-ray spectroscopy, thermogravimetric analysis, and scanning electron microscopy were used to confirm the prepared IIP. The effects of pH, initial concentration of the Cu(II) aqueous solution, and contact time on adsorption behavior were investigated. Adsorption by prepared IIP was fast (adsorption equilibrium was reached within 15min) and followed pseudo-second-order kinetic and Freundlich isotherm models. The IIP showed a good imprinted factor and the maximum adsorption capacity was up to 132.77mgg⁻¹, which is higher than that of IIP prepared by bulk polymerization, owing to the large surface area of GO and surface imprinted technology. The selectivity factors for Cu/Zn, Cu/Ni, Cu/Co, and Cu/Cd were 36.33, 8.44, 77.3, and 8.5, respectively. The polymer showed a widely application prospect for recovery of Cu ions from aqueous solutions.

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