Universal water-soluble cyclodextrin polymer-carbon nanomaterials with supramolecular recognition

Functionalization of carbon nanomaterials (including fullerenes, single-walled carbon nanotubes, multi-walled carbon nanotubes (MWCNTs), and graphene sheets) dispersed in water with macromolecules was achieved by a one-step strategy using β-cyclodextrin polymer (CDP). CDP-carbon nanomaterials were characterized by ultraviolet-visible, Raman, and Fourier transform infrared spectroscopies, transmission and scanning electron microscopies, and thermogravimetric analysis. These nanomaterials showed high solubility and stability in water because of the noncovalent interaction between carbon nanomaterials and CDP. The supramolecular recognition abilities of CDP-carbon nanomaterials were studied by cyclic voltammetry (CV). CDP-MWCNTs were also decorated by p-aminothiophenol (PATP) which formed inclusion complexes with the CDP. The conjugates (PATP-CDP-MWCNTs) were ideal templates for the highly efficient assembly of noble metal nanoparticles (Au and Pt) with dramatically different properties. Methanol oxidation of Pt-decorated PATP-CDP-MWCNTs in CV analyses indicated its potential application in direct methanol fuel cells, facilitating the feasibility of metal-decorated CDP-carbon nanomaterials in real technological applications. This universal method of producing carbon nanomaterials functionalized with macromolecules is beneficial for investigating the structure-performance relationship of carbon nanomaterials for designing compounds with specialized functions.