CHAPTER 13 Experimental procedures for assessing electrical and thermal conductivity of polyaniline Zahed Ahmadi a , Narendra Pal Singh Chauhan b , Payam Zarrintaj c,d , Aidin Bordbar Khiabani e , Mohammad Reza Saeb f , Masoud Mozafari e,g,h a Department of Chemistry, Amirkabir University of Technology, Tehran, Iran b Department of Chemistry, Bhupal Nobles’ University, Udaipur, Rajasthan, India c Polymer Engineering Department, Faculty of Engineering, Urmia University, Urmia, Iran d Advanced Materials Group, Iranian Color Society (ICS), Tehran, Iran e Bioengineering Research Group, Nanotechnology and Advanced Materials Department, Materials and Energy Research Center (MERC), Tehran, Iran f Department of Resin and Additives, Institute for Color Science and Technology, Tehran, Iran g Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran h Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran 1. Introduction Conductive polymers, based on their redox state and dopant strength, exhibit a vast range of conductivity form metallic to insulator, mostly applied as semiconductors (Fig. 1). In general, conductive polymers are not thermoformable; they are organic materials like insulating poly- mers. They can offer a high electrical conductivity, but do not necessarily reveal similar mechanical features in comparison with other commercially available materials. The electri- cal properties of PANI are to a large extent adjusted for a specific usage. Since conducting polymers like PANI have backbones of adjacent sp 2 hybridized carbon centers, they provide one valence electron on each center in a pz orbital orthogonal to the other three sigma bonds, which are combined with each other to a set of orbitals of wide delocalized molecules. The presence of highly mobile electrons in the delocalized state of a “doped” condition resulting from oxidation causes removal of some of the delocalized electrons. As a result, the conju- gated p-orbitals form a one-dimensional electronic band in assist, with electrons within such band becoming mobile when it is partially emptied. The band structures of a conductive polymer can be easily calculated with a tight-binding model based on the wave function set of isolated atom superposition. In principle, the reduction process is used for doping such materials for which unfilled bands are loaded by electrons. In practice, p-type semiconductors are commonly prepared by oxidative doping. PANI is composed of benzene ring and nitrogen ending in a rigid rod-like structure. PANI, due to its unique features such as suitable electrical/thermal conductivity, low 227 Fundamentals and Emerging Applications of Polyaniline © 2019 Elsevier Inc. https://doi.org/10.1016/B978-0-12-817915-4.00013-0 All rights reserved.