Preparation of polyaniline nanofibers and nanoparticles via simultaneous doping and electro-deposition

We present a new post-synthetic method for producing different nano-structures of Polyaniline (PANI), especially nano-fibers and nano-particles of varying doping (oxidation) states, by simultaneous doping and electro-deposition from electrolyte solutions of undoped PANI (Emeraldine bases) and p-toluenesulphonic acid using constant applied voltage and varying deposition time. High Resolution Transmission Electron Microscopy analysis reveals that during the initial doping-dominated stage continuous connected conductive PANI Emeraldine salt nano-fibers of diameter less than 50 nm are formed while in the later deposition-dominated stage, 30-50 nm sized isolated dispersed nano-particles of non conductive Leuco-Emeraldine are formed.