Conjugated polymers conductivity

In the search for potentially conducting conjugated polymers all of these methods have been explored. In the following sections we survey the main types of conjugated structure and briefly outline the strategies which have been adopted to prepare them. 

Many of the most interesting polymers are intrinsically stiff, such as the electronically conducting conjugated polymers. These polymers typically include... 

The formation of conductive conjugated polymers [e.g., polyacetylene, polypyrrole, polythiophene, polyaniline and poly(p-phenylene)] [92, 94] on electrodes by electropolymerization has been studied thoroughly [95]. If the electropolymerization is performed in a solution containing both the monomer and enzyme, then enzymes present in the immediate vicinity of the electrode surface become trapped in the... 

Conducting (conjugated) polymers have a unique set of properties The electronic properties of metals and semiconductors and the processing advantages and mechanical properties of polymers. It is the and that makes conducting polymers special materials. There are, after all, many excellent metals for example, copper, nickel, silver and gold, to name but a few. Similarly, there are many excellent semiconductors. Indeed, the sophisticated modem electronics industry uses silicon as the semiconductor of choice. It would be difficult to improve on the quality of copper as a metal or silicon as a semiconductor. 

As the title of this article suggests, the material covered will deal with the electronic structure of conductive conjugated polymers in relation to their physicochemical properties. This subject is so broad that the theme is confined herein to polyacetylene and other conjugated systems having aromatic rings. The research in this area, however, is rapidly developing and, on reflection, yielding fruitful results that have wide applications and ramifications in quantum chemistry. 

For the discussion of the physicochemical properties of conductive conjugated polymers, it is most important to set up the appropriate model and to employ the proper method of calculations. In this article most of the analyses have been based on the one-dimensional tight-binding CO methodology for polymers with periodical unit cells. This approach is useful because it gives not only the band structure but also information reflecting the nature of each atomic orbital in the unit cell. 

Conductive conjugated polymers belonging to polyenes or polyaromatics, such as polyacetylene, polyanUine (PANl), polypyrrole (PPy), polythiophene, poly(p-phenylene), and poly(phenylene vinylene) classes, have been investigated extensively [1-3]. PANI and PPy families of conjugated polymers are of much interest due to their low cost, easy synthesis, unique conduction mechanism, good stability and environmentally benign performance [4,5],... 

Some of the research focused on the nanosized loaded on conductive conjugated-polymer matrix. Mho et al. prepared V Oj/PANI composite films by a two-step electrochemical method and evaluated for their application in Li-ion batteries [64]. As a first step, the PANI film was... 

Proposed more than 10 years ago, a new concept is attracting a lot of interest, the plastic LEDs and plastic lasers [50], which are based on neutral, not conductive conjugated polymers, where conductive polymers are intended to be used as the hole injection layer. But this area has by far not yet reached a market acceptance as has been hoped for or predicted by the active scientists, companies, and the interested public. 

Asberg, R, and O. Inganas. 2003. Hydrogels of a conducting conjugated polymer as 3-D enzyme electrode. Biosens Bioelectron 19 199. 

Semi-conducting conjugated polymers (application as polymer light-emitting diodes, photovoltaic cells, sensors, field-effect transistors etc., e.g. poly(phenylene vinylene) (PPV)),... 

Scheme 13 Schematic representation of synthesis of soluble 3,4-ethylenedioxythiophene containing poly(arylsilane) PSEDT and its electrochemical conversion into highly conducting conjugated polymer PSEDTx...

Figure 24.6 Bonding in conducting conjugated polymers. The sp hybrid orbitals are shown in gray, and the unhybridized p orbitals in white. Electrons are represented by black dots. The two thin sp hybrid orbitals on the side extend in and out of the plane of the paper.

W. L. Harmer, L. Christensen, G. J. Drtina. and H. J. Helmin, Abrasive article with conductive conjugated, polymer coat and method of making same, U.S. Patent 5,061,294 (1991). 

Quite interestingly, the conductive conjugated polymers can be shaped at the nanoscale by anodic decttodeposition onto properly designed electrodes. For example, one side of porous membranes was coated by a metal (Au) to make them anodically polarizable. PPy nanotubules were then grown elec-trochemically into the pores and collected upon dissolution of the membrane (Figure 19). 

Many books and reviews have been devoted to the electrochemical synthesis and applications of conductive conjugated polymers. Only for reasons of limited space, just few of them are cited herein. ... 

---