Synthesis and Characterization of Nanostructured Polyaniline Doped with Ni2+ ions

Conducting polymers are polymers that have conjugated backbone and inherently conduct electricity. Their unique physical and chemical properties; such as conductivity change, conductivity control and dopant exchange; result in applying these intelligent polymers in different chemical and electrochemical areas including batteries, fuel cells, corrosion protection and sensors [1]. Among conducting polymers, polyaniline has received much attention due to its specific properties. To obtain conducting form of polyaniline, doping with Bronsted acids is essential. Doping of polyaniline with Lewis acid and also with transition metal ions have been studied in recent years [2]. In this paper polyaniline nanofibers were synthesized for the first time in the presence of nickel ions, and structural properties of the polymer were investigated by ultraviolet and visible (Uv-vis) and Fourier transform infrared (FTIR) molecular absorption spectrometry, X-ray diffraction (XRD) and field effect scanning electron microscopy (FESEM). Nanostructured polyaniline was synthesized using different percentages of nickel chloride. The FESEM images of the samples indicate the formation of nanofibers similar to polyanilne nanofibers. The XRD pattern reveals the amorphos nature of polyaniline/nickel ion composites. Some of the characteristic absorption bands of polyaniline are shifted in the Uv-vis and FTIR spectra. These observed changes may indicate that Ni2+ ions interact with nitrogen atoms in the polyaniline chain as dopant. The obtained material can be used for gas sensing applications.