Effect of various initial concentrations of CTAB on the noncovalent modified graphene oxide (MGNO) structure and thermal stability

Graphene oxide (GO) was prepared by oxidation reaction of graphite (GF) using the Hummers' method and modified by a cationic surfactant (cetyltrimethylammonium bromide - CTAB) followed by chemical reduction using hydrazine monohydrate (N2H4 x H2O) to obtain MGNO powders. The structural and thermal properties of GO and MGNO powders were studied using zeta potentiometer (ZP), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The results demonstrated that CTAB was successfully grafted onto the surface of the GO through non-covalent modification between CTA(+) ions and GO for all MGNO powders. A reasonable improvement in thermal stability of the MGNO powders was also observed. FTIR results showed the successful intercalation of CTA(+) ions for all MGNO powders. The optimum concentration of surfactant was found to be 120 mg x l(-1) (MGNO-120) by using analysis results. The ease of synthesis of MGNO-120 with both excellent intercalation and thermal stability will greatly facilitate potential applications.