The Formation of Oligoaniline Microspheres in Alkaline Media

Aniline oligomers are generally believed to be responsible for the self-assembly that guides the growth of polyaniline nanostructures. The oxidations of aniline with ammonium peroxydisulfate, which are started and finished above pH 2.5, produce aniline oligomers only. Under alkaline conditions, oligoaniline microspheres are formed as the dominating morphology. They will be potentially useful in applications that do not require conductivity, such as in electrorheology, corrosion protection, as ionic conductors or catalyst supports. Aniline oligomers prepared at alkaline conditions as microspheres have been studied by UV–Vis, infrared and Raman spectroscopies in the combination with optical and electron microscopic techniques.