LAMELLAR CONJUGATED POLYMERS BY ELECTROCHEMICAL POLYMERIZATION OF HETEROARENE-CONTAINING SURFACTANTS - POTASSIUM 3-(3-ALKYLPYRROL-1-YL)PROPANESULFONATES

A series of self-assembling monomers, potassium 3-(3-alkylpyrrol-1-yl)propanesulfonates, are electrooxidatively polymerized from micellar solution to afford lamellar phases of the substituted polypyrrole. The kinetics of electrochemical oxidation are quite sensitive to the concentration of the surfactant monomer and display the effects of solvent-induced molecular self-assembly. The films were characterized by low-angle X-ray diffraction, glancing angle infrared spectroscopy and X-ray photoelectron spectroscopy. The lamellar phase consists of a head-to-head packed of the surfactant repeat units. Consequently, the crystal repeat distance corresponds to approximately twice the extended length of the monomer. Infrared measurements indicate that lower homologs are conformationally less ordered, in accord with the observation that they also give rise to broadened X-ray diffraction lines, reflecting less positional order. The as-grown films are resistive (<10(-6) OMEGA-1 cm-1). Upon treatment with aqueous HClO4 the conductivity along the films enhanced (10(-3) OMEGA-1 cm-1) imparting anisotropic conductivity which is consistent with the lamellar structure.