Preparation of polyaniline nanotubes by a template-free self-assembly method

Polyaniline nanotubes were prepared by the template-free self-assembly method in various aqueous media. Typically, polyaniline synthesized in methanol solution has a carambola-like shape covered with some nanotubes, and those obtained in acetic acid are short nanotubes accompanied with lots of nanoparticles. When appropriate mixed solution was used, uniform and long polyaniline nanotubes were obtained. The impact of proportion of methanol and acid was illustrated as well as the synergetic effect of these two components. The morphology evolution during the polymerization process was also investigated. SEM images clearly demonstrate that polyaniline nanotubes form through a self-curling behavior. The structure features of end products in various aqueous media and intermediates in the optimum mixed solution were surveyed by FTIR.

Research Highlights
► It is a simple synthesis method without template and any special apparatus.
► The obtained polyaniline nanotubes are uniform and long under the synergetic effect of methanol and acetic acid in appropriate proportion.
► This method is promising to synthesize PANI nanotubes on a large scale.