Functionality of TERGO Powders During the Synthesis of PANI-Based Composites for Electrical Devices

In this work, hybrid composites were prepared using polyaniline (PANI) and electrochemically reduced graphene oxide (ERGO) by in situ polymerization. ERGO powders were obtained by a two-way route, Hummer’s method, and one-step potential (−2 V) followed by annealing process at 400°C (TERGO powders): different quantities of TERGO fine particles (10, 20, and 30 wt%) were added to the in situ PANI polymerization in order to produce the hybrid composites. The morphology and structure of the PANI/TERGO compounds were characterized by Raman spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thermal treatment of ERGO powders pointed out high-defect surfaces with a wrinkle-type morphology (ID/IG ratio~0.90). The emeraldine phase of PANI was obtained with a maximum value of 61%, which decreases with the amount of TERGO powders. It is also seen that composites displayed a combined morphology between PANI matrix and TERGO powders, confirming a physical interaction between both morphologies. The amount of TERGO particles into the polymeric matrix also modifies the sample microstructure from a semispherical shape to extend sheets, where PANI is sandwiched between TERGO layers. Electrical conductivity of composites slightly increases independent of the TERGO amount (30 S/m and 39 S/m) due to the rough TERGO surface that conditioned the homogeneous nucleation of a large amount of polymer (PANI) reducing the area to move the electrical charge.