The locations of dopant ions in polymeric host matrices have been determined using a variety of experimental and theoretical techniques. Areas of work have included structural studies, diffusion measurements, electrochemistry and theoretical calculations.
Extended X-ray absorption fine structure (EXAFS) techniques have been shown to be uniquely useful, having confirmed the nature of the dopant ion when polyacetylene is exposed to ferric chloride, and having revealed subtle differences in structures adopted by polymeric dibenzo-18-crown-6-ether depending on the size of the dopant. New gravimetric techniques to determine diffusion coefficients and activation energies for ion motion have been applied as well as radiotracer and exchange methods. Crown ether polymers have been prepared electrochemically and electrochemical techniques have been used to study polymers deposited at electrode systems.
The following theoretical approaches have been applied to the study of polyacetylene, polyparaphenylene, polypyrrole, polythiophene and polymeric crown ethers:
atomistic static lattice simulation techniques to determine structures, and positions and migration pathways of dopant ions;
quantum chemistry techniques to elucidate electronic structures and their modification by dopants.
The project will elucidate structural, transport and electrochemical properties of a range of conducting polymers. The structural studies will use both EXAFS and diffraction techniques employing synchrotron radiation. Transport measurements will be made employing gravimetric, radiotracer, and electrochemical methods. The experimental studies will be supported by the application of theoretical methods to predict both structural and electronic properties of the materials. The concerted use of these techniques is essential for providing the understanding at the atomic level which is needed to optimise the design and application of these technologically important materials.
Funding SchemeCSC - Cost-sharing contracts
ST5 5BG Staffordshire