Preparation and characterization of polyaniline- and polythiophene-based copolymer and its nanocomposite suitable for electro-optical devices

Doped polyaniline (PANI), doped polythiophene and their copolymers (by interfacial and aqueous polymerization) with monomers at 50:50 ratio has been synthesized and are characterised by X-ray diffraction (XRD), thermo gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) measurements. The copolymer synthesized by interfacial polymerization is mixed with copper oxide nanoparticle synthesized chemically in lab at 0.2% loading. XRD measurement showed no peak for PANI and polythiophene, which confirms amorphous structure of the two. However, clear peak for copper oxide nanoparticle at 2 theta= 36.45 and multiple peaks for the copolymer (interfacial polymerization) and the copolymer Nanocomposite signifies crystalline structure. TGA results show that the stability of copolymer prepared by interfacial polymerization lies in between the PANI and polythiophene. FTIR spectroscopy confirms that both aniline and thiophene units are present in the interfacial copolymer. Further the monomers are chemically linked in the copolymer (by interfacial and aqueous polymerization). The presence of peak at about 1103 cm(-1)confirms the formation of N-S bonding by reaction in between aniline and thiophene in the interfacial copolymer. The uniform distribution of nanoparticles in copolymer (interfacial polymerization) matrix have been confirmed from TEM images. The electrical properties of polymers, copolymers and copper oxide Nanocomposite are studied from which it is found that the copolymer have a synergistic effect on the improvement of conductivity when compared with the individual polymers. The 0.2% loading of copper oxide nanoparticles further improves the conductivity of the interfacial copolymer by approximate 15.24-fold.