Structural, optical, and dielectric properties of aminated PMMA/GO polymer nanocomposite for storage device applications

Abstract

A series of aminated PMMA/GO polymer nanocomposite (PNG) were synthesized by solution mixing in two step process. The synthesized PNG samples were analysed using X-ray diffraction (XRD), Fourier transform infrared (FTIR), Scanning Electron Microscope (SEM), energy dispersive X-ray analysis (EDAX), Thermo-gravimetric, differential thermal analysis (TG-DTA), UV–Visible spectroscopy (UV–Vis) and impedance spectroscopy. The X-ray diffraction (XRD) data indicated the existence of crystalline nature in PMMA and the reduction of graphene oxide (GO) which is also confirmed by TGA and DTA results. The interaction between graphene oxide nanoparticles and the functionalized polymer matrix has been validated using FTIR investigations. The SEM and EDAX measurements demonstrated the homogeneous dispersion of graphene oxide (GO) over the surface of the produced samples. The UV–Vis spectroscopy analysis revealed that the optical energy gap values of nano composites decrease as the amount of graphene oxide nanoparticles increases. All samples exhibited higher relative permittivity at low frequencies which is a key factor for high energy density. As the concentration of GO increases, the maximum peak of dielectric loss tangent also shifted to higher frequency due to increase in interfaces. The β relaxation is dominant in non-polar PMMA due to the functionalisation and dispersion of GO. The AC conductivity values increased with increase in concentration of GO. The single semicircle in plot from impedance spectroscopy and the drop in bulk resistance values of PNG samples made them as a good material for energy storage devices like supercapacitors.