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For energy storage applications, a material that has high dielectric permittivity, low loss factor, strong thermal resistance, easy processability, and low cost are highly desirable. In the present study, PVA/xNiO nanocomposite films with different NiO contents of (0, 10, 50 and 100) wt% were prepared by casting technology. The PVA/xNiO of 50 wt% NiO has been irradiated with 3 MeV electron beam at a dose of 50 kGy at room temperature in order to investigate the modifications induced in its dielectric properties. The results show that the NiO nanoparticles are well incorporated inside the PVA matrix and the crystallite size of NiO has been decreased upon doping by 50 wt% NiO from 15.45 to 11.44 nm. Also, PVA/(50%)NiO nanocomposite show indirect allowed optical transition (3.43 eV) with relatively high dielectric constant (7.60 to 9.55) and low loss factor (< 0.1) at high frequency (1 MHz) and the entire indicated range of temperature which proposes to use this material in energy storage applications. The electron beam radiation has increased the dielectric constant (10.52 to 13.94) which is preferable. However, a slight increase is observed in the loss factor (< 0.109).

Polyacrylamide (PAM) was used as a matrix material for preparing nanocomposite samples filled with different weight fractions (1, 3, 5, 7, and 15%) of barium titanate (BaTiO3) by casting method. The PAM/7% BaTiO3 has been irradiated with gamma radiation at a dose of 200 Gy in order to investigate its impact on the structure as well as its optical and dielectric properties. The results show that the BaTiO3 nanoparticles are well incorporated inside the PAM matrix and the crystallite size of BaTiO3 has been decreased upon filling inside the PAM matrix as confirmed by the analysis of Fourier transform spectroscopy, and X-ray diffraction patterns, respectively. The prepared films show direct forbidden optical transition. Moreover, filling PAM with 7% BaTiO nanoparticles has increased the dielectric permittivity from 1.07 to 2.44 (at 100 kHz) with a slight increase in the loss factor from 0.015 to 0.020. In the other side, gamma radiation has decreased the crystallite size in relative to the un-irradiated sample with increased dielectric permittivity (2.89) and a slight decrease in the loss factor (0.019) at 100 kHz.

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