Preparation of a Two-Dimensional Ion-Imprinted Polymer Based on a Graphene Oxide/SiO₂ Composite for the Selective Adsorption of Nickel Ions

Langmuir. 2015 Aug 18;31(32):8841-51. doi: 10.1021/acs.langmuir.5b01201. Epub 2015 Aug 4.

Abstract

In the present work, a novel two-dimensional (2D) nickel ion-imprinted polymer (RAFT-IIP) has been successfully synthesized based on the graphene oxide/SiO2 composite by reversible addition-fragmentation chain-transfer (RAFT) polymerization. The imprinted materials obtained are characterized by Fourier transmission infrared spectrometry (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results show that the thermal stability of the graphene oxide/SiO2 composite is obviously higher than that of graphene oxide. RAFT-IIP possesses an excellent 2D homogeneous imprinted polymer layer, which is a well-preserved unique structure of graphene oxide/SiO2. Owing to the intrinsic advantages of RAFT polymerization and 2D imprinted material, RAFT-IIP demonstrate a superior specific adsorption capacity (81.73 mg/g) and faster adsorption kinetics (30 min) for Ni(II) in comparison to the ion-imprinted polymer prepared by traditional radical polymerization and based on the common carbon material. Furthermore, the adsorption isotherm and selectivity toward Ni(II) onto RAFT-IIP and nonimprinted polymer (NIP) are investigated, indicating that RAFT-IIP has splendid recognizing ability and a nearly 3 times larger adsorption capacity than that of NIP (30.94 mg/g). Moreover, a three-level Box-Behnken experimental design with three factors combining the response surface method is utilized to optimize the desorption process. The optimal conditions for the desorption of Ni(II) from RAFT-IIP are as follows: an HCl-type eluent, an eluent concentration of 2.0 mol/L, and an eluent volume of 10 mL.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Graphite / chemistry*
  • Ions / chemistry
  • Molecular Imprinting*
  • Nickel / chemistry*
  • Oxides / chemistry*
  • Particle Size
  • Polymers / chemical synthesis*
  • Polymers / chemistry
  • Silicon Dioxide / chemistry*
  • Surface Properties

Substances

  • Ions
  • Oxides
  • Polymers
  • Silicon Dioxide
  • Graphite
  • Nickel