Synthesis and Characterization of Nanosized Graphene and Conductive Polymers (Polyaniline) using some Ionic Liquids and Conventional Solvents

Abstract

The graphene/polyaniline nanocomposites were synthesized in four different imidazolium based ionic liquids (1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate' l-butyl-3-methylimidazolium hexafluorophosphate, and l-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide) as well as in five organic conventional solvents (toluene, acetone, tetrahydrofuran, dimethylsulphoxide, and dimethylchloride). Polyaniline was crafted on the surface of graphene oxide resulting in graphene oxide/polyaniline nanocomposites which were later reduced into graphene/polyaniline nanocomposites. The graphene/polyaniline composites were characterized using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet Spectroscopy (UV-Vis), X-Ray Diffractometry (XRD) and Thermogravimetric analysis (TGA). The SEM micrographs of composites synthesized in ionic liquids showed that the Polyaniline (PANI) nanofibers were nucleated and agglomerated in between the graphene sheets, while the PANI in composites synthesized in organic liquids formed slippery flakes in between the graphene (GR) sheets. The XRD distinctively identified the crystalline structures for GR/PANI nanocomposites synthesized in both ionic liquids and conventional solvents. The crystalline sizes ranged between 89-950 nm and 29-250 nm for composites synthesized in ionic liquids and organic solvents respectively. The FTIR and UY-Vis results shown that graphene was incorporated into the graphene/polyaniline nanocomposite structures. EDS and TGA depict that the graphene/polyaniline nanocomposites synthesized in the presence of ionic liquids have similar properties to those synthesized in organic solvents. Hence, this method could be employed to produce graphene based conducting polymer nanocomposites as a measure of producing materials in environmentally benign conditions.