Mechanically Assisted Exfoliation and Functionalization of Thermally Converted Graphene Sheets

A single-step mechanical assisted exfoliation and functionalization of graphene using thermally converted graphene (TCG) and aryl-diazonium salts in ILs (ionic liquid) was successfully demonstrated. The addends of the functionalized materials was conveniently customized by employing different aryl diazonium salts (2a-2g). The degree of functionalization was monitored with X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). The degree of functionalization, TGA was completed on TCG and all products. The samples were heated to 110°C, held for 60 mm to remove water and remaining solvent, and then cooled to room temperature. The solubility of graphene sheets with different functional groups in N,N'-dimethylformamide (DMF) was also measured. Great increases in DMF solubility of the products were observed when compared to the TCG starting material.