Fabrication of High-Concentration and Stable Aqueous Suspensions of Graphene Nanosheets by Noncovalent Functionalization with Lignin and Cellulose Derivatives

Stable aqueous suspensions of graphene (G) nanosheets with high concentration (0.6-2 mg/mL) were prepared through chemical reduction of exfoliated graphite oxide (EGO) with the aid Of sodium lignosulfonate (SLS), sodium carboxymethyl Cellulose (SCMC), and pyrene-containing hydroxypropyl Cellulose (HPC-Py). The noncovalently functionalized graphene nanosheets with a 3.3 +/- 1.4 rim average thickness were characterized With use of UV-vis spectroscopy, fluorescence spectroscopy, atomic force microscopy, attenuated total reflectance micro-Fourier transform infrared spectroscopy, and Raman spectroscopy.