The effect of gamma irradiation dose in the range of 1-10 kGy is investigated on the structural, optical and electrical properties of the polyaniline -emeraldine salt (PANI-ES) thin films deposited on the indium tin oxide (ITO) coated glass substrate by spin coating technique. X-ray diffraction patterns show that all deposited PANI films have an amorphous character. Fourier transform infrared spectroscopy (FTIR) confirms the emeraldine salt form of deposited PANI films. The analysis of UV-Vis spectrophotometer indicates a decrease of transmittance intensity and optical band gap with increase of gamma irradiation dose while Urbach energy increases. The photoluminescence (PL) spectra show a strong peak at 429 nm due to transition from polaron band to π band in PANI structure which its intensity and peak area increase with irradiation dose increase. Electrical measurement shows that the resistivity of prepared films linearly increases with rise of gamma dose suggesting its possible application as gamma dosimeter in the studied range.

We investigate the effects of different contents of multiwall carbon nanotubes (MWCNTs) on optical and electrical properties of polyaniline (PANI). The MWCNTs/PANI composites are deposited on glass substrates coated with indium tin oxide (ITO) by the spin-coating technique. The scanning electron microscopy shows that nanotubes are coated with the PANI layer and x-ray diffraction patterns show that all deposited composite films have an amorphous character. The analysis of a UV-vis spectrophotometer indicates the blue shift of the absorbance peak and a decrease in optical band gap value by the enhancement of the CNT content in the PANI matrix while the Urbach energy increases. The Raman spectrum shows the blue shift 1404→1417 cm-1 and photoluminescence spectra show an increase in the intensity of characteristic PANI peak at 436nm with the increasing CNT content.

Hydrogen sensing property of composite films of camphorsulfonic acid-protonated polyaniline (Pani) with different amounts of multiwall carbon nanotube (MWCNT) was investigated in this paper. The MWCNT/Pani composite films were deposited by a spin-coating method on both ITO and Au-interdigitated electrodes (Au-IDE) substrates. Sensor film characteristics were evaluated by monitoring the change in electrical resistance in the presence of hydrogen at room temperature. It was observed that all MWCNT/Pani composite films showed the better sensor indicators such as sensitivity, response and recovery times in comparison with pure Pani. It was found that sensor indicators were improved by increasing the MWCNT filler concentration in composite. Moreover, it was observed that Au-IDE substrate drastically increased sensor sensitivity in comparison with uniform ITO-coated glass at 4 wt% MWCNTs exposed to 0.4 vol% H 2 in the air.

In this study, multiwall carbon nanotubes (MWCNTs)/polyaniline nanocomposites deposited on ITO coated glass as substrate by the spin-coating technique were applied to the investigation of the effect of different contents of MWCNTs on the optical and electrical properties of polyaniline. Micrographs from an atomic force microscope were taken to analyze the 3-D microtexture parameters of surface texture factors and fractal dimension. By using optical spectroscopy of samples with different concentrations of MWNCTs in visible and ultraviolet regions, the transmission variations vs photon wavelength, optical bandgap, absorption coefficient, and skin depth were studied. The variation in the resistance of nanocomposite films exposed to 0.4 %vol of H2 gas at room temperature was monitored, and the results indicated that the sensitivity and responsibility of the composites increased with an increase in the MWCNT amount.