Synthesis of Conducting Polymer Composite Fibers in Electrochemical Flow Cells

A one‐step electrochemical synthesis of polymer and composite polymer fibers of macroscopic dimensions (>10 cm length and 0.2 mm diam) is reported. Poly(3‐methylthiophene) and polypyrrole fibers are grown from the tip of a Pt microelectrode by oxidation of 3‐methylthiophene and pyrrole, respectively, in a capillary flow cell. Hydrodynamic fields within the capillary cell result in unidirectional growth of the polymer along the axis of the flow cell. High strength, conductive, and flexible composite polymer fibers are synthesized by deposition of poly(3‐methylthiophene) or polypyrrole on a nonconductive Kevlar or polyester string suspended in the solution along the axis of the capillary flow cell. Composite fiber growth rates as large as 30 cm/h are obtained under optimal conditions.