Ten-Minute Synthesis of Highly Conductive Polymer Nanosheets on Ice Surfaces: Role of Ice Crystallinity

Abstract

Conducting polymers have been studied widely over the past decades for use as organic electrode materials owing to their high electrical conductivity and low-cost synthesis. Among the various synthesis methods reported, the recently established ice-assisted approach for developing conducting polymer nanosheets is regarded as an advanced technology that allows for easy fabrication in an eco-friendly manner. However, the role of the crystallinity of the underlying ice surface in determining the physicochemical properties of the conducting polymers remains unclear. Here, the electronic properties and packing structures of polyaniline (PANI) nanosheets formed on ice surfaces are studied by controlling the ice crystallinity. Intriguingly, the crystallinity of the PANI nanosheets resembles that of the ice surfaces, in that the anisotropic growth of the PANI crystals with a face-on orientation occurs preferentially on high-crystalline ice surfaces. In addition, it is found that the development of highly crystalline PANI nanosheets results in efficient charge transport, owing to polaron delocalization in PANI with extended chain conformations and the improvement in the degree of backbone ordering because of the preorganized aniline moieties on the ice surface.