Electrical Transport Properties of Molecular Composites Derived From the Oxidation of Poly(N-Vinylpyrrole)

Abstract

Homo and copolymers of N-vinylpyrrole (NVP) were synthesized and the structure/properties relationships of the chemical oxidation products with Fecl₃ at different Fe³⁺/NVP molar ratios characterized. From DC electrical, FT-IR and Raman spectroscopic characterizations, the picture of a composite at a molecular level emerges as that of a block copolymer of non-conducting and conducting segments, these last derived from the oxidation of PNVP. The possibility of giving an estimate of the growth of the oxidation level is seen from FT-IR data, whereas Raman spectroscopy seems to be specifically sensible to the modifications induced by the oxidation in the NIR-Via absorption, probably coupled to the enhancement of the conduction process. The transport properties are analyzed according to the hopping model and the result of fitting procedures discussed.