Self-Assembled Polyaniline Nanostructures with Photoisomerization Function

Nanostructures (e.g., nanotubes and nanofibers) of polyaniline (PANI) with an average diameter of 110−130 nm and a conductivity of 2.5 × 10 - 2 S/cm were synthesized by a self-assembly process in the presence of azobenzenesulfonic acid (ABSA) as a dopant. It was found that the formation probability and size of PANI−ABSA nanostructures depended on the molar ratio of aniline to ABSA and the concentration of ABSA. ABSA or aniline−ABSA salt micelles were proposed to interpret the formation of PANI−ABSA nanostructures. In particular, the PANI−ABSA nanostructures exhibited trans−cis photoisomerization similar to that of the azobenzene moiety upon irradiation with UV light (λ = 365 nm).