Modifications in functional and EMI shielding properties of PCCCe polymer nanocomposite via exposure of 1.3 MeV γ-radiations

Abstract

This research work reports the effect of γ-radiation with a 1.3 MeV Co-60 on functional and shielding properties of PCCCe (PVA: Polyvinyl alcohol/CS: Chitosan/CB: Carbon Black/CeO2) nanocomposite films. The films were synthesized by solution-casting method and exposed under the doses from 10 to 50 kGy. Under the exposure of γ-doses, the exponential increase in Young's modulus, and the reduction in flexibility with increase in γ-doses were observed. FTIR spectroscopy shows a change in broadening of absorption band which suggests the modification of functional groups with increase in γ-doses. Further, the significant decrease in photoluminescence (PL) intensity occurred at higher γ-irradiation doses (50 kGy) suggests a degradation of PCCCe films. The frequency-dependent dielectric properties and the electromagnetic Shielding Effectiveness (SE) of the irradiated nanocomposite films were investigated at room temperature in the frequency range of 8.2–12.4 GHz (X-band) with the help of Vector Network Analyzer (VNA) and a proper wave guide. The exposure of γ-radiations has also exhibited an enhancement in dielectric properties and ac electrical conductivity. The shielding effectiveness through absorption (SEA) increases significantly from 31.08 dB to 47.92 dB at higher frequencies (10.5 GHz–11.5 GHz); while through reflection, Shielding Effectiveness (SER) is slightly enhanced as the γ-doses rose from 10 kGy to 50 kGy. In addition to it, the total SE, achieved a maximum value of 78.14 dB at 10.5 GHz for a γ-dose of 50 kGy. Based on these tremendously enhanced shielding properties, these nanocomposite films are the promising candidate for high-radiation safety applications.