Determination of electrical and optical behaviors of carboxymethyl cellulose/graphene nanocomposites

Carboxymethyl cellulose (CMC)/graphene nanoplatelet (GnP) nanocomposite films containing different volume fractions (0.00, 0.73, 1.46, 2.20, 2.94, and 3.68) were prepared by ultrasonication assisted solution casting method. The effect of GnPs on structural, electrical, optical properties, and dispersion parameters of the nanocomposite have been investigated by a fourier transform infrared (FTIR), scanning electron microscope (SEM), two-point probe resistivity measurement, UV–Vis absorbance, and reflectance spectroscopy. The direct ( E d ) and indirect ( E i ) optical band gap energies of nanocomposites were determined using Tauc and absorbance spectrum fitting (ASF) methods. The results demonstrated that the optical band gap energies could be adjusted by altering the GnP volume fraction. Additionally, it was found that the outcomes obtained through the Tauc and ASF methods were very close to each other. The electrical conductivity ( σ ), Urbach energy ( E u ), refractive index ( n ), dispersion energy ( E do ), optical conductivity ( σ opt ), and optical dielectric constant ( ε ) of CMC/GnP nanocomposite were found to increase with increasing GnP volume fraction ( V ). The improvements in structural, electrical, optical, dispersion parameters, and optical dielectric properties of these nanocomposites make them a potential candidate for many industrial applications.