Molecular and supermolecular origins of enhanced electric conductivity in template-synthesized polyheterocyclic fibrils. 1. Supermolecular effects

Abstract : The pores in a nanoporous membrane can be used as templates for the synthesis of nanostructures. We have recently shown that conductive polymer fibrils, obtained via this template synthetic method, can show dramatically higher electronic conductivities than conventional versions of the analogous polymers. In this and a succeeding paper we explore the molecular and supermolecular origins of this enhanced electronic conductivity. This paper focuses on supermolecular effects. We have used DC and optical measurements of conductivity, X-ray diffraction, and polarized infrared absorption spectroscopy to show that the polymer chains in the narrowest template-synthesized fibrils are preferentially oriented parallel to the axes of these fibrils. This preferential polymer chain orientation is partially responsible for the observed conductivity enhancements. We also show that template-synthesis can yield poly(3-methylthiophene) fibrils with conductivities as high as 6600 S cm-1. This is the highest conductivity ever reported for a heterocyclic polymer.