Charging process in polypyrrole films: effect of ion association

Воротынцев, М. А.; Vieil, E.; Heınze, Jürgen

doi:10.1016/s0022-0728(97)00623-2

Cited by 102 publications

(59 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The length of the fi lm inside the de-aerated electrolyte, 0.1 M LiClO 4 aqueous solution, was 1 cm with 0.44 mg being the immersed polypyrrole mass ( Figure 1 ). The free-standing electrode fi lm was subjected to consecutive potential sweeps in order to get a steady state voltammetric response by erasing any structural material memory [ 20,[41][42][43][44][45][46][47][48] The closed coulovoltammetric loop allows the separation, with quantifi cation of the involved charges, of every reduction/oxidation-induced structural process: reduction-shrinking, reduction-compaction, oxidation-relaxation, and oxidation/ swelling (Figure 2 d). [ 1 ] The intersection point E c corresponds to the closing potential.…”

Section: Infl Uence Of the Cathodic Potential Limitmentioning

confidence: 99%

Structural Electrochemistry from Freestanding Polypyrrole Films: Full Hydrogen Inhibition from Aqueous Solutions

Otero

Martínez

Fuchiwaki

et al. 2013

Adv Funct Materials

View full text Add to dashboard Cite

Free-standing polypyrrole fi lms, being the metal-polymer contact located several millimeters outside the electrolyte, give stationary closed coulovoltammetric (charge/potential) loop responses to consecutive potential sweeps from -2.50 V to 0.65 V in aqueous solutions. The continuous and closed charge evolution corroborates the presence of reversible fi lm reactions (electroactivity), together high electronic and ionic conductivities in the full potential range. The closed charge loop demonstrates that the irreversible hydrogen evolution is fully inhibited from aqueous solutions of different salts up to -2.5 V vs Ag/AgCl. The morphology of the closed charge loops shows abrupt slope changes corresponding to the four basic components of the structural electrochemistry for a 3D electroactive gel: reduction-shrinking, reduction-compaction, oxidation-relaxation, and oxidation-swelling. Freestanding fi lms of conducting polymers behave as 3D gel electrodes (reactors) at the chain level, where reversible electrochemical reactions drive structural conformational and macroscopic (volume variation) changes. Very slow hydrogen evolution is revealed by coulovoltammetric responses at more cathodic potentials than -1.1 V from strong acid solutions, or in neutral salts self-supported blend fi lms of polypyrrole with large organic acids. Conducting polymers overcome graphite, mercury, lead, diamond, or carbon electrodes as hydrogen inhibitors, and can compete with them for some electro-analytical and electrochemical applications in aqueous solutions.

show abstract

Section: Infl Uence Of the Cathodic Potential Limitmentioning

confidence: 99%

Structural Electrochemistry from Freestanding Polypyrrole Films: Full Hydrogen Inhibition from Aqueous Solutions

Otero

Martínez

Fuchiwaki

et al. 2013

Adv Funct Materials

View full text Add to dashboard Cite

show abstract

“…3-methyl thiophene (Janssen, purity of 99%) was distilled with sodium at 95 °C under argon atmosphere. PANI films were electrochemically synthesized on a Pt substrate by cyclic voltammetry in NH 4 …”

Section: Methodsmentioning

confidence: 99%

“…The hysteresis phenomenon occurring in redox processes of PCE has been evidenced by several experimental means, including electrochemical, [1][2][3][4][5] spectroelectrochemical, 1,6,7 and spectrophysical 1,[8][9][10][11][12] techniques. This type of hysteresis can be characterized through the charge-potential curves of the surface redox reaction, if no mass transfer kinetically limits the transformation.…”

Section: Introductionmentioning

confidence: 99%

Analysis of hysteresis phenomenon as observed from voltammetric data of conducting polymers: part I

Matencio¹,

Pernaut²,

Vieil³

2003

J. Braz. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

Estudamos o fenômeno de histerese inerente aos processos redox dos polímeros condutores eletrônicos (PCE). As histereses foram separadas em duas classes: i) as histereses dinâmicas constituídas por componentes cinéticas e ôhmicas e ii) as histereses estacionárias ou termodinâmicas. Efetuamos uma análise matemática das histereses dinâmicas observadas nos voltamogramas cíclicos de dois polímeros: a polianilina (PANI) e o poli(3-metiltiofeno) (P3MT). Mostrou-se que no caso do P3MT a histerese é principalmente cinética devido à velocidade de uma das etapas do processo redox com também uma componente ôhmica relacionada à existência de uma impedância elétrica em serie com o sistema eletroquímico. No caso da PANI, observou-se que a histerese é independe da corrente, o que é característico de uma histerese termodinâmica.The hysteresis phenomenon inherent to redox processes of Electronic Conducting Polymers (ECP) has been studied. Hysteresis was divided into two classes: i) dynamic hysteresis, containing a kinetic and an ohmic component and ii) stationary or thermodynamic hysteresis. A mathematical analysis was performed on the dynamic hysteresis observed in cyclic voltammograms of two polymers: polyaniline (PANI) and poly(3-methylthiophene) (P3MT). It has been shown that in the case of P3MT, the hysteresis is mainly kinetic due to the rate of one of the steps of the redox process. However, an ohmic component related to the existence of an electrical impedance in series with the electrochemical system is also present. As for PANI, hysteresis is current independent, which is characteristic of thermodynamic hysteresis.

show abstract

“…Electron transfer at the electrode/polymer interface creates positive charge sites, for which electroneutrality requires the entry of anions (or exit of cations) at the polymer/solution interface 25 (colloquially, "(un-)doping"). These ion transfers have been explored in detail for polypyrrole exposed to aqueous [26][27][28][29][30][31] and non-aqueous [32][33][34] media.…”

Section: Introductionmentioning

confidence: 99%

Fundamental aspects of electrochemically controlled wetting of nanoscale composite materials

et al. 2017

View full text Add to dashboard Cite

Electroactive films based on conducting polymers have numerous potential applications, but practical devices frequently require a combination of properties not met by a single component. This has prompted extension to composite materials, notably those in which particulates are immobilised within a polymer film. Irrespective of the polymer and the intended application, film wetting is important: by various means, it facilitates transport processes -of electronic charge, charge-balancing counter ions ("dopant") and analyte/reactant molecules -and motion of polymer segments. While film solvent content and transfer have been widely studied for pristine polymer films exposed to molecular solvents, extension to non-conventional solvents (such as ionic liquids) or to composite films has been given much less attention. Here we consider such cases, based on polyaniline films. We explore two factors: the nature of the electrolyte (solvent and filmpermeating ions) and the effect of introducing particulate species into the film. In the first instance, we compare film behaviours when exposed to a conventional protic solvent (water) with an aprotic ionic liquid (Ethaline) and the intermediate case of a protic ionic liquid (Oxaline). Secondly, we explore the effect of inclusion of physically diverse particulates: multi-walled carbon nanotubes, graphite or molybdenum dioxide. We use electrochemistry to control and monitor film redox state and change therein, and acoustic wave measurements to diagnose rheologically vs. gravimetrically determined response.The outcomes provide insights of relevance to future practical applications, including charge/discharge rates and cycle life for energy storage devices, "salt" transfer in water purification technologies, and the extent of film "memory" of previous environment when sequentially exposed to different media. 11,20 (including supercapacitors 21 ) and artificial muscles 22,23 . Inevitably, such applications require combinations of properties that are not generally found in a single material, so it is natural to move to composites. Additionally, it has become widely recognized that dynamics within such systems -from transport rates of charge balancing ions and analyte species to the nanomechanical motions of the polymer chains -are governed by the solvent content, i.e. the internal wettability of the material. In this study, we bring these two aspects together by exploring solvation phenomena for polyaniline composites containing multi-walled carbon nanotubes (MWCNTs), molybdenum dioxide and/or graphite when exposed to aqueous and room temperature ionic liquid media. KeywordsPolyaromatic conducting polymers, typified by polyaniline, may be interconverted between their insulating and conducting forms by electrochemically controllable redox processes 1,24 . Electron transfer at the electrode/polymer interface creates positive charge sites, for which electroneutrality requires the entry of anions (or exit of cations) at the polymer/solution interface 25 (colloquially, "(un-)doping"). T...

show abstract

Charging process in polypyrrole films: effect of ion association

Cited by 102 publications

References 58 publications

Structural Electrochemistry from Freestanding Polypyrrole Films: Full Hydrogen Inhibition from Aqueous Solutions

Structural Electrochemistry from Freestanding Polypyrrole Films: Full Hydrogen Inhibition from Aqueous Solutions

Analysis of hysteresis phenomenon as observed from voltammetric data of conducting polymers: part I

Fundamental aspects of electrochemically controlled wetting of nanoscale composite materials

Contact Info

Product

Resources

About