Impedance Analysis of Polyaniline in Comparison with Some Conventional Solid Electrolytes

Abstract

Doped polyaniline (PANI) is well-known as an electronic (polaronic) conductor and mostly is used as semiconductor in various applications. However, in the literature there are examples of employment of the acid doped form of PANI as electrolytic filler in proton exchange membranes. In order to distinguish between two types of conduction, in the present study powdered samples of polyaniline, either in the form of emeraldine base (PANI-EB) or in the form doped with camphorsulfonic acid (PANI-CSA), were investigated using impedance spectroscopy both in the dry state and in contact with liquid water. The obtained spectra were compared with the spectra of such conventional solid electrolytes, as zeolites X and ZSM5 and a strong electrolyte boron orthophosphate, acquired in identical conditions. The most important dissimilarity between conventional electrolytes and PANI was that ion diffusion dominates in the impedance response of the formers, whereas the behavior of PANI is under control of electron/hole displacement and the diffusion part is quite inessential. This corroborates the results of analysis of temperature dependence of PANI conductivity, which revealed values of activation energy twice as large as typical solid electrolytes. Equivalent circuits, simulating the impedance responses of all materials, were built up and used to estimate a possible diffusion coefficient of cations in the comparable solids. It was found that the diffusion in a strong electrolyte such as BPO is ∼2 orders of magnitude faster than evaluated for zeolites and ∼4 orders higher than what was PANI estimation. A conclusion was made that the slow cation diffusion both in protonated and in base form of PANI makes them less efficient solid electrolytes than conventional materials.

Impedimetric Polyaniline-Based Aptasensor for Aflatoxin B1 Determination in Agricultural Products

“…The conductivity of PAni is mainly contributed by the C−N +• polaron lattice (PL) structure, which is formed from the doping of the imine functional group in quinoids [ 44 ]. The charge transfer is directly affected by the conductive parts of PAni [ 45 , 46 ]. Therefore, the sensitivity of the electrode was enhanced.…”

Effects of the Polymer Amount and pH on Proton Transport in Mesopores

“…[ 4 ] These limitations have inspired research on novel PEM materials as well as on understanding and modulating proton transport. Various approaches on polymeric membranes, [ 6 ] porous materials, [ 7 ] and development of composite materials [ 8 ] can be found in the literature. Proton transport through structurally rigid and ordered nanoscale porous materials used as membranes, such as mesoporous silica, is of special interest, as changes in proton conductivity can be directly correlated to the membrane characteristics, factors such as swelling can be excluded, and water management can be facilitated, e.g., profitable condensation can occur.…”

Synthesis and Characterization of Electrochemical Sensor Based on Polymeric /TiO2Nanocomposite Modified with Imidizolium Ionic Liquid for Determination of Diclofenac

“…Among various types of conducting polymers, poly(3,4-ethylenedioxythiophene) (PEDOT) is a widely investigated and can be easily electrodeposited on several surfaces by electro-oxidation of its monomer [40][41][42][43]. PEDOT modified electrodes have been extensively reported and showed excellent electrocatalytic effect [44].…”