One-Step Synthesis of Polypyrrole Nanofiber Assemblies with Enhanced Electronic Properties: Implications for Next-Generation Organic Electronics

Ultralong bulky polypyrrole nanofiber assemblies with high degrees of structural hierarchy are successfully synthesized by adding poly(ethylene glycol) (PEG) into the oxidative template of the vanadium pentoxide nanofiber. The added PEG molecules can form cocomplexes with the polypyrrole nanofibers by a charge transfer interaction through the formation of strong hydrogen bonding between the polypyrrole nanofibers and PEG molecules, serving as charge transfer agents. The strength and magnitude of the interaction are simulated using the density functional theory. This strong charge transfer interaction can induce the directional assembly of nanoscale polypyrrole nanofibers into bulky polypyrrole fibers. Both the morphology and electronic structure of the as-synthesized polypyrrole nanofibers can be effectively tuned by the charge transfer agent, resulting in nanofibers with enhanced multimodal functionalities, such as high water dispersibility, high electrochemical activity, and high conductivity, indicating their wide range of applications in organic electronics, biosensors, and field-effect transistors.