Waree K, Pangza K, Jangsawang N, Thongbai P, Buranurak S
Department of Physics, Faculty of science, Khon Kaen University, Khon Kaen, Thailand.
Gems Irradiation Center, Thailand Institute of Nuclear Technology, Nakhon Nayok, Thailand.
Radiat Prot Dosimetry. 2019 Oct 1;184(3-4):342-346. doi: 10.1093/rpd/ncz111.
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.
本研究的主要重点是研究γ辐照对聚偏氟乙烯/钛酸钡（PVDF/BT）纳米复合材料电学性能的影响。用1.25 MeV的γ射线辐照不同钛酸钡体积分数（ƒBT = 0 - 0.4）且吸收剂量范围为50 - 2500 Gy的复合薄膜。使用阻抗分析仪研究了室温下频率范围为100 Hz至10 MHz时PVDF/钛酸钡复合材料的介电性能。在累积剂量为1500 Gy的情况下，在PVDF/BT 40体积%的纳米复合薄膜中观察到介电常数增加了28%，损耗角正切降低了15%。扫描电子显微镜显示未辐照和γ辐照材料的微观结构没有显著差异。傅里叶变换红外光谱表明γ辐照使PVDF的晶型从α - PVDF转变为β - PVDF/γ - PVDF，这已被报道为影响聚合物介电常数变化的主要因素之一。在累积剂量为1500 Gy的情况下，紫外可见分光光度法观察到PVDF/BT 40体积%纳米复合薄膜的吸收边发生γ辐照诱导的红移，从400 nm移至420 nm。然而，当累积剂量增加到2000 Gy时观察到蓝移。
