Synthesis, characterization, gas sensing, and electrical property evaluation of polyaniline/copper‐alumina nanocomposites

Abstract

AbstractA series of organic‐inorganic hybrid of polyaniline (PANI)/copper‐alumina (Cu‐Al2O3) nanocomposites were prepared by in situ polymerization technique. The structural, morphological and thermal properties of PANI with different contents of nano Cu‐Al2O3 were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction analysis (XRD), scanning electron microscopy (SEM), high‐resolution transmission electron microscope (HR‐TEM), differential scanning calorimetry (DSC), and thermogravimteric analysis. The dielectric constant, dielectric loss and the AC conductivity were measured using a dielectric analyzer in a frequency ranging from 100 Hz to 1 MHz. Also, current (I)‐voltage (V) characteristics and gas sensing performance of the composites were studied in detail. The FTIR spectra of composite exhibited the IR band of nanoparticles in the macromolecular chain of PANI. The XRD pattern showed the systematic arrangement of Cu‐Al2O3 particles in the molecular structure of polyaniline. The SEM and TEM images indicated that the nanoparticles were sheathed by polyaniline. DSC results showed that incorporation of Cu‐Al2O3 accelerated the glass transition temperature of PANI. TG analysis demonstrated the enhancement in thermal stability of PANI/Cu‐Al2O3 nanocomposite relative to the base polymer. Conductivity studies showed that both AC and DC conductivity, dielectric constant, and dielectric loss increased with increase in the concentration of nanoparticles up to 5 wt%. Similarly, the ammonia gas sensing behavior of nanocomposites was also improved by the addition of Cu‐Al2O3 nanoparticles.