Helical heterojunctions originating from helical inversion of conducting polymer nanofibers

The helical sense of conducting polyaniline nanofibers was induced using chiral acid as dopant, which can be inversed through a copolymerization of aniline with N-methyl aniline. By delicately controlling the inversion driving force of steric hindrance, we successfully obtained helical heterojunctions'' composed of right- and left-handed helical structures in one helical nanofiber.