Liquid/Liquid Interfacial Polymerization To Grow Single Crystalline Nanoneedles of Various Conducting Polymers

Abstract

Single crystalline nanoneedles of polyaniline (PANI) and polypyrrole (PPY) were synthesized using an interfacial polymerization for the first time. The interfacial crystallization of conductive polymers at the liquid/liquid interface allowed PANI and PPY polymers to form single crystalline nanocrystals in a rice-like shape in the dimensions of 63 nm x 12 nm for PANI and 70 nm x 20 nm for PPY. Those crystalline nanoneedles displayed a fast conductance switching in the time scale of milliseconds. An important growth condition necessary to yield highly crystalline conductive polymers was the extended crystallization time at the liquid/liquid interfaces to increase the degree of crystallization. As compared to other interfacial polymerization methods, lower concentrations of monomer and oxidant solutions were employed to further extend the crystallization time. While other interfacial growth of conducting polymers yielded noncrystalline polymer fibers, our interfacial method produced single crystalline nanocrystals of conductive polymers. We recently reported the liquid/liquid interfacial synthesis of conducting PEDOT nanocrystals; however, this liquid/liquid interfacial method needs to be extended to other conductive polymer nanocrystal syntheses in order to demonstrate that our technique could be applied as the general fabrication procedure for the single crystalline conducting polymer growth. In this report, we showed that the liquid/liquid interfacial crystallization could yield PANI nanocrystals and PPY nanocrystals, other important conductive polymers, in addition to PEDOT nanocrystals. The resulting crystalline polymers have a fast conductance switching time between the insulating and conducting states on the order of milliseconds. This technique will be useful to synthesize conducting polymers via oxidative coupling processes in a single crystal state, which is extremely difficult to achieve by other synthetic methods.

One‐Dimensional Conducting Polymer Nanostructures: Bulk Synthesis and Applications

“…The interfacial polymerization technique has also been applied to the polymerization of EDOT which results in short nanorodlike structures of PEDOT. [80,81] The PEDOT nanorods possess an average diameter of 30 nm and appear to display a high degree of structural order.…”

Recent progress on nanostructured conducting polymers and composites: synthesis, application and future aspects

“…The aqueous/organic interface consists of 3,4-ethylenedioxythiophene in an organic solvent and ferric chloride as an oxidant in aqueous phase. They also obtained PANI (63 nm × 12 nm) and PPy (70 nm × 20 nm) in a rice-like shape at the liquid/ liquid interface using the same method [67]. The resulting crystalline polymers exhibited fast conductance switching time between the insulating and conducting states in the order of milliseconds.…”

Advance and Prospect of Nanoscale Chinese Medicine

“…No.7 step is to do drug effect test, No.8 step is to measure leftover of organic solvent. No.9 is other specific evaluation for nanoscale Chinese medicine [18][19][20][21][22][23][24].…”