A Comparative Study of Potentiodynamic and Potentiostatic Modes in the Deposition of Polyaniline

Abstract

The electrodeposition of polyaniline films was performed under potentiodynamic and potentiostatic conditions. Cyclic voltammetry shows that the redox electrochemical behavior changed from quasi-reversible to totally irreversible with increasing aniline concentration. In terms of the kinetics of the nucleation and growth processes in the potentiostatic deposition mode, progressive nucleation with two-dimensional growth is predominant, followed by one-dimensional growth leading to the formation of a fibrous structure. The overall polymer growth rates and the morphology of polymer surfaces are very different depending on the deposition method. The morphology associated with the kinetics is correlated with those experimentally determined by scanning electron microscopy and atomic force microscopy. Conductivity of the potentiostatically grown film is lower than the one potentiodynamically grown. The observed decrease in conductivity appears to be linked to a decrease in the charge carrier mobility due to the agglomerated structures that are formed during secondary growth.

Growth Processes and Morphological Evolution of Polyaniline Film During Potentiostatic Growth

“…14 Figure 1 shows the existence of three stages in two different growth regimes during 2400 s in the potentiostatic growth. The selected voltage should be sufficiently high for oxidative polymerization to proceed, while being low enough to avoid undesirable secondary reactions and overoxidation of the polymer.…”

“…4 One of the most important points in the electrochemical studies of conducting polymers is the understanding of nucleation/growth processes. 8,14 There have been several studies conducted on the electrochemical growth processes of PAni. [11][12][13] Our research group has conducted comparative studies of the effects of electrodeposition methods on the electrochemical and morphological properties of PAni films, e.g., potentiodynamic vs. potentiostatic and potentiodynamic vs. galvanostatic modes.…”

Effect of structural factors on the physicochemical properties of functionalized polyanilines

“…Electrochemical syntheses of PANI derivatives, which involve the deposition of a polymer onto a working electrode made of metals, 29,[62][63][64][65][66][67][68][69][70][71][72] carbon materials (glass carbon, graphite), or optically transparent electrodes made of glass coated with metals or metal oxides, 37,[70][71][72][73][74] are performed in galvanostatic, potentiostatic, or potentiodynamic modes in a three-electrode cell. A study of this process by scanning electron microscopy conrmed that the most homogeneous products are obtained in the potential cycling mode.…”

“…It was found that with an increase in the volume of substituents framing the macromolecule, the electrical conductivity decreased from the methoxy group at position 2,6-or 3,5-to 2,6-dithiophen-2-yl and 2,6-dibromopolyaniline. 62 As a rule, heteroatom-containing substituents are intentionally incorporated in PANI in order to change some specic properties of the nal material and to expand the spectrum of possible applications in a particular industry. 37,101,102 In order to increase the charge capacity of PANI, we obtained a polymer with disulde bridges, i.e., poly[bis(2-aminophenyloxy) disulde], whose electrical conductivity is 2-3 orders of magnitude lower than that of PANI -6.4 Â 10 À2 S cm À1 (Fig.…”

Central composite design optimization of methylene blue scavenger using modified graphene oxide based polymer

“…Graphene oxide nanosheets is readily functionalized with various surfactants, polymeric materials, and nanoparticles in order to provide enormous potential for applications in materials science and engineering [10,11]. In recent years, graphene oxide catalyzed photocatalytic reactions such as degradation of dyes [12][13][14][15][16]. Graphene oxide is prepared by the oxidative procedure of graphite by one of the principle methods improved by Brodie, Hummers or Staudenmeir [17].…”