Electrochemical studies of heterocyclic conducting polymers (original) (raw)

Recent studies of heterocyclic and aromatic conducting polymers

Progress in Polymer Science, 1986

CONTENTS 1. Introduction 2. Polymerization and doping 2.1. Mechanism of conducting polymerization 3. Characterization of conducting polyheterocyclics and polyaromatics 3.1. Stability of polyheterocyclics and polyaromatics 3.2. Percentage of doping, molecular weight, mechanical properties and morphology of conducting polyheterocyclics and polyaromatics 3.3. Spectroscopy of heterocyclic and aromatic conducting polymers 3.3.1. Electrochemical spectroscopy of conducting polyheterocyclics and polyaromatics 3.3.2. Optical and ESR studies 3.3.3. t3C NMR and XPS studies 201 4. Mechanism of electrical conduction in doped polyheterocyclics and polyaromatics 202 5. Conducting copolymers 206 6. Application of doped polyheterocyclics and polyaromatics 208 6.1. Battery application 208 6.2. Photo-electrochemical cell (PEC) 6.3. Schottky barriers, solar cells and solid-state devices 210 6.4. Electro-optic devices 211 6.5. Sensors 6.6. Medicinal uses 213 6.7. Miscellaneous applications 214 7. Concluding remarks Acknowledgements 214 References

The oligomeric approach – the electrochemistry of conducting polymers in the light of recent research

Journal of Solid State Electrochemistry, 1998

Electrochemical investigations on oligomeric model compounds (β-carotenoids) of polyacetylene varying the chain length in the range between 5 and 23 double bonds provide deeper insights into the redox properties of such systems. Furthermore, cyclic voltammetric studies of α,ω-diphenylpolyenes and phenylenevinylenes give clear evidence that the formation of the radical ions is followed by a rapid reversible dimerization between the oligomeric chains. The thermodynamic and kinetic parameters of the chemical reaction are presented. Applying these results to the properties of conducting polymers opens up new perspectives for interpreting charge storage and conductivity.

First-principles studies of some conducting polymers: PPP, PPy, PPV, PPyV, and PANI

Journal of Molecular Structure-Theochem, 1999

We present results of first-principles calculations of the electronic properties of several conducting polymers containing either phenylene or pyridine rings. The applied density functional method employs linear muffin-tin orbitals (LMTOs) as basis functions. It has been explicitly constructed for calculating the electronic properties of infinite, periodic, helical, polymeric chains. We study poly(p-phenylene) (PPP), poly(p-phenylenevinylene) (PPV), poly(2,5-pyridine) (PPy), poly(2,5-pyridinevinylene) (PPyV) and polyaniline (PANI). The structural parameters were obtained either from experimental information or by applying semi-empirical methods. We find that by replacing a carbon atom by a nitrogen atom in the phenylene ring, an occupied n-band appears. Simultaneously, the first ionization potential is increased which can be related to the electronegativity of nitrogen compared to that of carbon. When a vinylene linkage separates the rings, steric effects between the rings are diminished and the rings may thus be coplanar. This increases the p -electron delocalization and produces a stabilization of the system. In contrast, by replacing the vinylene linkage by an amine group (resulting in PANI) a non-planar polymer is obtained which has a larger band gap and a smaller ionization potential. ᭧ Journal of Molecular Structure (Theochem) 468 (1999) 181-191 0166-1280/99/$ -see front matter ᭧ Fig. 1. Schematic representation of the unit cell of the studied polymers.

TOPICAL REVIEW: Conducting polymer-based nanostructurized materials: electrochemical aspects

Nanotechnology, 2005

New modern technologies require new materials. During the past decade, the movement towards nanodimensions in many areas of technology aroused a huge interest in nanostructurized materials. The present article reviews recent works dealing with electrochemistry-related aspects of nanostructurized conducting polymers. Electrochemical synthesis and some properties of nanostructurized conducting polymers, and nanocomposites derived from conducting polymers and metals, carbon, and inorganic and organic materials are considered. Some potential areas for electrochemistry-related applications of nanocomposites are highlighted, including batteries, supercapacitors, energy conversion systems, corrosion protection, and sensors.