Optical studies of polyaniline nanostructures

An investigative infrared spectroscopic study is undertaken of nano polyaniline (PANI) samples differing in size and morphology in order to explore the sensitivity of spectral behavior on these factors. IR spectroscopy is used for studying the changes in the interaction between polymeric molecules as parts of nanodimensional structures. A time dependent interfacial oxidative polymerization of aniline monomer is conducted in order to obtain the desired nano PANI samples in doped form. The morphological changes in samples so obtained are characterized using scanning electron microscopy (SEM). The SEM images of samples obtained using the time dependent interfacial polymerization show preferential formation of 1D nano/micro structures with dimensions varying with reaction time intervals, which is also confirmed by transmission electron microscopy (TEM). X-ray diffraction study is undertaken to assess the crystalline nature of the samples. The IR spectra and the X-ray diffraction pattern of samples reflect these morphological variations. A comparative study of bulk polyaniline sample obtained using standard procedures is also undertaken. Significant variations in the conductivity of different polyaniline samples are also observed. The 10 min sample shows significantly enhanced conductivity as compared to the 20 min and 24 h. PANI samples having well defined nanofibers.