Chiral polyaniline nanotubes synthesized via a self-assembly process

Electrical and optical active polyaniline (PANI) nanotubes doped with (1R)-(−)-10-camphorsulfonic acid (L-CSA) and (1S)-(+)-10-camphorsulfonic acid (D-CSA) as a chiral dopant, which have 80 to 200 nm in outer diameter and 20 to 40 nm in inner diameter, were synthesized via a self-assembly process. It was found that the formation yield and the size of the nanotubes is affected by the molar ratio of CSA to aniline; however, the influence of the configuration of CSA on their formation yield and morphology and size could be neglected. The nanotubes not only show electrical properties (∼10−2 S/cm) but also exhibit optically activity that Cotton effects corresponding to a helical screw of the polymer chains were observed by the circular dichroism (CD) spectra. The micelles composed of anilinium cations and CSA anions were proposed as templates in the formation of the chiral nanotubes.