Polymer Nanocomposites: Synthesis of Polyaniline, Its Nanocomposites with Pristine and Functionalized Carbon Nanotubes and Comparative Analysis of Their Electrical Properties

Abstract

Polyaniline (PANI) is an electrically conducting polymer with its conductivity falling in semiconductor range with applications in rechargeable batteries, electro-chromic displays, biosensors, antistatic coatings, membranes and solar cells. During this project, PANI was synthesized using standard polymerization method. Unique properties of multi-walled carbon nanotubes (MWCNTs) were employed in improving properties of pure PANI by making PANI/CNT nanocomposites with different loadings of MWCNTs. Commercially available MWCNTs were used in pristine form as well as after chemical functionalization to improve dispersion in the polymer matrix. SEM results confirmed extremely good dispersion of functionalized CNTs in PANI. In-Situ polymerization technique was used to successfully synthesize nanocomposites. Thin films of pure PANI and PANI/CNT nanocomposites were successfully deposited using dip coating method. Nanocomposites were characterized using various techniques such as FTIR, TG/DTA, SEM, Profilometer and Hall Effect measurements. For nanocomposite thin films, average film thickness was found to be ~70 nm. Film deposition mechanism was investigated for both pure PANI and PANI/CNT nanocomposites by carrying out deposition for different times. In addition, PANI/CNT granule powder was also obtained and characterized. DC and AC conductivity measurement indicated that incorporation of P─CNT, CNT─OH, and CNT─NH2 significantly improved the electrical properties of Polyaniline. Comparatively, nanocomposites containing amine functionalized CNTs produce enhanced electrical characteristics.