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Nickel-doped poly vinyl alcohol (PVA) films were developed for potential application in industrial sectors like radiation processing. We report in this paper the results of an experimental investigation of 60Co source γ-radiation effect on colorimetric, structural and morphological properties of PVA films doped with 0.5% Ni2+ ions (PVA/Ni2+). The PVA/Ni2+ films were irradiated by different gamma-radiation doses varying from 5 to 100 kGy. Color modification of films were studied using L∗, a∗ and b∗ color space measurements as function of the γ-dose and post-irradiation time. The visual change in all samples was verified by microstructure analysis, Fourier transforms infrared (FTIR) spectroscopy, X-Rays diffraction (XRD) and scanning electron microscopy (SEM). The color space exhibited a linear dose response at a dose ranging from 5 to 50 kGy, and then it reached saturation for higher γ-doses. The calculated color changes (ΔE) show a linear dose response relationship from 9.90 to 115.02 in the dose range from 0 to 50 kGy. It showed also the activation of stable color centers. The variability of the color change did not exceed 3% during 80 h (h) post-irradiation. Furthermore, the microstructure analysis evidenced that the color modification due to the optical activation of nickel-oxide (NiO) color center were obtained by complexing Ni2+ ions in irradiated PVA films. The obtained results inspire the possibility to use PVA films for the control process in industrial radiation facilities in dose range 5–50 kGy.

An Irradiated nickel oxide (NiO) thin film was deposited onto glass substrates at 723 K by the spray pyrolysis using nickel chloride as precursors. The obtained films were irradiated by gamma-radiation doses varying from 180 Gy to 10 kGy. The structure and optical properties of the samples were examined by X-ray diffraction, UV–vis spectrometer and photoluminescence measurement. Un-irradiated and irradiated NiO thin films have a cubic structure with the same preferred orientation along the plane (111). XRD investigation shows that, the intensity of preferred orientation and crystallite size depend on gamma-radiation dose. For a study of the dose effect, it is very important to optimize the precursor concentration. With a concentration of 5.10−2M precursor NiCl2 and a dose of 10 kGy, we obtain a thin film of Ni2O3. With a 10 kGy dose we obtain a new dominant phase, Ni2O3, which induced an activation of the visible range under the effect of gamma rays. This improved the photocatalytic performance under gamma rays treatment. Moreover, the PL quenching effect shows an improvement of photocatalytic properties.