Glass transition temperature of Agar-Reduced Graphene Oxide (RGO) Composites using 2-D contour mapping of temperature dependent FTIR spectra

Abstract

In the present work, composites of Reduced Graphene Oxide (RGO) and Agar have been synthesized via the solution cast method and their structural, thermal and dielectric properties are studied. UV–Visible, X Ray Diffraction (XRD), Raman Spectroscopy and Fourier Transform Infrared (FTIR) have been employed for analyzing structural properties of the prepared samples. Analysis of different peaks in XRD and Raman Spectra suggests the interaction of RGO layers with Agar at the molecular level. FTIR spectra indicate that interaction of Agar with RGO occurs through hydrogen bonding linkage. Further, the Glass transition temperature (T_g) of prepared samples has been determined using 2D contour mapping from temperature-dependent FTIR spectra as well as from the Differential Scanning Calorimetry (DSC)technique. Values of T_g obtained from both techniques have been found in close agreement with each other. In addition to that, value of T_g of Agar increases from 72 °C to 80 °C as an effect of 2 wt.% RGO loading indicating the improvement in the thermal behavior of Agar. Moreover, the dielectric behavior of as-prepared composites demonstrate that the dielectric constant of these composites has been increased in comparison to pure Agar.