DIELECTRIC PROPERTIES OF POLY (VINYLIDENE FLUORIDE)/BARIUM TITANATE NANOCOMPOSITES UNDER GAMMA IRRADIATION

• Published in: Radiation protection dosimetry 2019-10, Vol.184 (3-4), p.342-346
• Main Authors: Waree, K, Pangza, K, Jangsawang, N, Thongbai, P, Buranurak, S
• Format: Article
• Language: English
• Subjects: Barium Compounds - chemistry; Dielectric Spectroscopy - methods; Gamma Rays; Nanocomposites - chemistry; Polyvinyls - chemistry; Titanium - chemistry
• ISSN: 0144-8420; 1742-3406
• DOI: 10.1093/rpd/ncz111

Abstract The main focus of this study is to investigate the effect of gamma irradiation on the electrical properties of PVDF/BT nanocomposites. A 1.25 MeV gamma-ray was delivered to the composite films with different BaTiO3-volume fraction, ƒBT = 0–0.4, and with different absorbed doses ranged 50–2500 Gy. Dielectric properties of PVDF/BaTiO3 composites under frequencies ranged from 100 Hz to 10 MHz at room temperature were investigated using an impedance analyser. An increase of 28% in the dielectric constant and a decrease of 15% in the loss tangent were observed in the PVDF/BT 40 vol% nanocomposite film under the accumulated dose of 1500 Gy. Scanning electron microscopy provided no significant difference in microscopic structures between non-exposed and gamma-exposed materials. Fourier-transform infra-red spectroscopy provides gamma-induced transition of PVDF-crystalline forms as alpha-PVDF into beta-PVDF/gamma-PVDF which has been reported as one of the main factors affected the change of dielectric constant in polymers. UV–visible spectrophotometry has been observed gamma-induced red shift in the absorption edge of the PVDF/BT 40 vol% nanocomposite film from 400 nm to 420 nm under the accumulated dose of 1500 Gy. However, a blue shift is observed with increase the accumulated dose up to 2000 Gy.