Conducting Polymers

  • Skaarup, Steen, (Project Manager)
  • West, Keld , (Project Participant)
  • Bay, Lasse, (Project Participant)

Project Details

Description

Polymers with alternating (conjugated) single and double bonds have unusual electronic properties that are normally not associated with polymer materials. By oxidation or reduction, mobile electronic defects may be introduced on the conjugated backbone, rendering these polymers electronic conductors. In extreme cases, electronic conductivity better than copper (by weight) have been reported.
The introduction of charges on the polymer backbone requires that compensating counter charges are introduced into the polymer matrix. This process is often refered to as "doping", but is conceptually identical to an intercalation reaction. Conducting polymers may therefore be useful in the same kinds of applications as described for intercalation materials: Rechargeable batteries, electrochromic displays showing controllable color change, as well as in sensors.
We have characterised a number of conducting polymers and demonstrated how the analogy to intercalation may help in the understanding of the complex behaviour of these systems. One important difference between inorganic intercalation materials and conducting polymers is the lack of perfection of the polymer structure. High concentrations of defects may be present in the chemical bonds making up individual polymer chains, and the stacking of these chains into a "crystal lattice" is far from uniform. By careful control of the synthesis of poly-pyrrole, we have demonstrated how the degree of perfection of the polymer backbone greatly influences the physical and electrochemical properties of the polymer.
Polymers are relative soft materials, and the doping process may lead to significant changes in the dimensions of conducting polymers. We are presently investigation the exploitation of this electro-chemo-mechanical effect in mechanical actuators - "artificial muscles". The aim is to be able to precisely control position and force by the application of a small (
StatusFinished
Effective start/end date01/01/199031/12/2002