Abstract 9508723 Epstein The objective of this research is to explore electrically conducting polymers. Despite the extensive studies there are many open questions concerning the correct description of the metallic state of the various conducting polymers and the determination of the ultimately achievable conductivity of each of these families of conducting polymers. In this research, an extensive array of correlated charge transport, magnetic and optical studies of highly conducting polymers (including doped polythiophenes, doped polypyrroles and doped polyanilines) is planned. In addition to traditional experiments such as electrical conductivity, thermopower, and susceptibility, frequency-dependent studies will be emphasized to gain insight into microscopic processes. The dielectric constant and conductivity will be obtained at microwave frequencies and also from the far ir to the uv. For the first time synchrotron radiation will be used to span the important region between the microwave and the far ir. Where appropriate, experiments will be conducted at very high magnetic fields or very low temperatures. Correlation of the results of these studies with structural and compositional information of the different polymer systems should elucidate the design criteria for creating truly metallic polymers, some with conductivities even exceeding that of copper. %%% Electrically conducting polymers have been studied for the past 1.5 decades. Highly conducting polymer materials have expanded from doped polyacetylene to include also doped polypyrrole, doped polythiophene, doped polyaniline, and their many derivatives and related polymers. There continue to be important advances in these materials and their understanding. Initially, these systems were only modestly good conductors, and, in fact, became insulators at low temperatures. The present generation of materials have conductivities in the range of that of traditional metals. This new generation of conduct ing polymers share other properties in common with traditional metals (such as a negative dielectric constant). Despite the extensive studies there are many open questions concerning the correct description of the metallic state of the various conducting polymers and the determination of the ultimately achievable conductivity of each of these families of conducting polymers. These issues are the subject of this research. Success in this research program would have an impact in the understanding of electronic polymers, nanostructured materials, and concepts of localization, delocalization, and electronic properties in reduced dimensions. Also, development of a fundamental understanding of the metallic state will impact the implementation of metallic polymers in technologies ranging from electromagnetic interference shielding to molecular manufacturing, to improved environmentally friendly materials for ease of recycling.
