Polypyrrole nanofiber arrays synthesized by a biphasic electrochemical strategy

We report a novel strategy to synthesize nanofiber arrays of conducting polypyrrole with controlled lengths. Combining the merits of the electrochemical polymerization and the interfacial chemical polymerization, our biphasic electrochemical strategy can control the lengths of nanofibers from several hundred nanometres to several micrometres using L-camphorsulfonic acid as a dopant. The morphology of aligned nanostructures can be further adjusted by the amiphiphilic properties of the dopants. The molecular structures of these nanostructures identified by Raman spectra are similar to that of polypyrrole obtained by the conventional method. The surface of polypyrrole nanofiber arrays has a superhydrophobic property with a water contact angle (CA) higher than 165°. Owing to its general formation mechanism and good controllability, our strategy may be developed into a versatile method to produce aligned nanostructures of other functional materials.