Influence of the chemical functionalization of carbon nanotubes on low temperature ac conductivity with polyaniline composites

Maity, KP and Patra, A and Prasad, V (2020) Influence of the chemical functionalization of carbon nanotubes on low temperature ac conductivity with polyaniline composites. In: Journal of Physics D: Applied Physics, 53 (12).

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Abstract

We report the ac conductivity measurement of polyaniline (PANI) composites with carbon nanotubes (CNT) and functionalized carbon nanotubes (fCNT) with different degrees of functionalization from 300 K-4.2 K in the frequency range 40 Hz-5 MHz. The ac conductivity of PANI follows the universal power law and the charge transport is dominated by small polaron tunneling. In the CNT/PANI composite, metallic behaviour emerges, and ac conductivity does not obey the power law which is explained by the Drude model. Due to the chemical functionalization of CNT, disordered semiconducting behaviour appears in the transport below 50 K and follows the Johnscher's power law. The enhancement of polaron formation due to the polar interaction between fCNT and PANI is reflected in the ac conductivity of the composites. The charge transport is manifested by single electron tunneling for a lower degree of fCNT/PANI (6 h) composite which changes to small polaron tunneling transport for a higher degree of fCNT/PANI (48 h) composite. The dc conductivity behaviour is explained by Mott's VRH model and the characteristic Mott temperature increases with an increasing degree of chemical functionalization.

Item Type:	Journal Article
Publication:	Journal of Physics D: Applied Physics
Publisher:	Institute of Physics Publishing
Additional Information:	Copyright of this article belongs to Institute of Physics Publishing
Keywords:	Electron tunneling; Polarons; Polyaniline; Temperature, Ac Conductivity; Chemical functionalization; Functionalized carbon nanotubes; Functionalized carbon nanotubes (f-CNT); Polyaniline composites; Single Electron Tunneling; Temperature increase; Variable range hopping, Carbon nanotubes
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	09 Mar 2020 08:40
Last Modified:	09 Mar 2020 08:40
URI:	http://eprints.iisc.ac.in/id/eprint/64705

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