Copper alumina nanoparticles-reinforced poly(pyrrole-co-indole): characterization, dielectric properties and gas-sensing applications

Conducting polymer nanocomposites have been developed as efficient materials in various technological fields. This work concentrates on the synthesis, characterization and properties of copper alumina (Cu–Al 2 O 3 ) nanoparticles-reinforced poly(pyrrole- co -indole) (PPy- co- PIN) copolymer nanocomposites by an in situ polymerization technique. The effects of Cu–Al 2 O 3 on structural, morphological, thermal transitions, electrical properties and gas-sensing properties of (PPy- co -PIN) were systematically evaluated. The interactions between the organic and inorganic constituents in synthesized copolymer nanocomposites were confirmed with Fourier transform (FT-IR) spectroscopy. The successful reinforcement of Cu–Al 2 O 3 nanofillers and improved structural regularity were observed from the X-ray diffraction of synthesized materials. The high-resolution transmission electron microscope images showed the consistent distribution of inorganic Cu–Al 2 O 3 nanofillers in the copolymeric network. Differential scanning calorimetry manifested an enhancement in glass transition temperature with the increased stuffing of nanofillers into the copolymer. Nanocomposites exhibit higher dielectric permittivity and dielectric loss tangent than pure copolymer. The engendering of charge carriers within the co-polymer was initiated by the reinforcement of Cu–Al 2 O 3 nanofillers and eventually improved dielectric properties. The potent application of these materials in ammonia gas sensing at ambient temperatures was established. The gas-sensing response of (PPy- co -PIN)/Cu–Al 2 O 3 recorded toward NH 3 gas was superior, which arises from the movement of positively charged holes and electrons within the heterosystem. These admirable properties can be exploited in developing multifunctional electronic devices.