Low temperature process of electronic charge transport mechanism in PANi/MWCNT nanocomposites: tubular morphology

Abstract

In this work, we investigate the tuning of the electrical transport dimensionality of polyaniline-multiwalled carbon nanotube nanocomposites (PANi/MWCNTs) for electronic device applications. The microstructure and its correlations with electrical transport properties, and the conductivity of nanocomposites were studied from 75 to 330 K. The samples have been prepared with a new low-temperature system in which a layer of polymer has been coated on MWCNTs in a whole tubular morphology. The enhancement in conductivity of the nanocomposites is due to the charge transfer effect from the quinoid rings and the π-π interaction of the PANi to the MWCNT. The synthesized nanocomposites are investigated in the framework of existing theoretical models in 1, 2 & 3 dimensions (phonon assisted tunneling within the carbon nanotube and clusters) and systematically studied and compared in terms of transport parameters. Charge localization length and most probable hopping distance were found to decrease with wt% of MWCNT, whereas the charge hopping energy increases in nanocomposites. The distinction between thermally activated processes and the determination of cross-over temperature were achieved by exploring the temperature dependence of the fractional exponent of the dispersive conductivity. The enhanced transport properties of these categories of nanocomposites due to a combination of MWCNTs in conducting polymer matrix can be applied for photodetectors, organic solar cells, supercapacitors, and electronic strategies.