Synthesis and formation mechanism of PANI nanotubes prepared via facile aqueous solution polymerization

Abstract

Polyaniline nanotubes were fabricated using itaconic acid as dopant and soft template via facile aqueous solution polymerization. On basis of scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), the influence of polymerization conditions such as oxidizer/aniline molar ratio and oxidizer concentration on the morphology and chemical structure of PANI was studied. Polyaniline nanotubes with 3D porous network structure were successfully prepared under the optimal conditions. The formation mechanism of PANI nanotubes was thoroughly analyzed by the measurements such as transmission electron microscopy (TEM), 1H nuclear magnetic resonance (NMR), the diffusion ordered spectroscopy (DOSY) and relaxation time (T1 H) measurements. Itaconic acid micelles were used as "soft template" to form self-assembled polyaniline nanostructures. Meanwhile, in the micelles composed of aniline and itaconic acid, the aniline cations initiated by oxidizer free radicals were polymerized into polyaniline with the structure of nanotubes. Furthermore, the formation of polyaniline nanotubes was guaranteed by the double electric layer structure.