Fabrication, characterization, properties and theoretical analysis of ceramic/PVDF composite flexible films with high dielectric constant and low dielectric loss
Fabrication, characterization, properties and theoretical analysis of ceramic/PVDF composite flexible films with high dielectric constant and low dielectric loss
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DOI：
10.1039/c3ta14107a
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发表时间：
2014-01-01
影响因子：
11.9
通讯作者：
Li, Longtu
中科院分区：
文献类型：
--
作者：
Luo, Bingcheng;Wang, Xiaohui;Li, Longtu
采用传统固相法制备了锆钛酸钙钡（Ba0.95Ca0.05Zr0.15Ti0.85O3，BCZT）陶瓷颗粒。采用化学包覆法对BCZT粉体进行了多巴胺改性。采用溶液浇铸法制备了多巴胺@BCZT/聚偏氟乙烯复合柔性薄膜。采用X射线衍射、傅里叶变换红外光谱、高分辨透射电子显微镜和场发射扫描电子显微镜对样品的微观结构和形貌进行了表征。使用精密阻抗分析仪和介电耐压测试仪测试介电常数、损耗角正切和击穿强度。TEM结果表明，多巴胺均匀包覆在BCZT颗粒表面，平均包覆厚度为20 nm。SEM结果表明，陶瓷颗粒在基体中均匀分散。在10（3）~ 10（5）Hz的频率范围内，介电常数随BCZT含量的增加而增加，而损耗角正切基本不变。采用不同的理论模型对复合薄膜的有效介电常数进行了预测，并将预测结果与实验数据进行了比较。采用威布尔分布对材料的击穿强度进行了分析，结果表明：材料的击穿强度先下降后保持在60 kV mm（-1）以上。
Calcium barium zirconate titanate (Ba0.95Ca0.05Zr0.15Ti0.85O3, BCZT) ceramic particles were prepared by a conventional solid-state method. BCZT powders were modified by dopamine through a chemical coating method. The composite flexible films based on dopamine@BCZT and polyvinylidene fluoride were fabricated via a solution casting method. The microstructure and morphology were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, high-resolution transmission electron microscopy, and field emission scanning electron microscopy. A precision impedance analyzer and a dielectric withstand voltage test were used to test the dielectric constant, loss tangent, and breakdown strength. TEM results showed that dopamine was uniformly coated on the surface of BCZT particles with an average thickness of 20 nm. SEM results showed that the ceramic particles were dispersed homogeneously in the matrix. The dielectric constant increased with the increase of BCZT contents, while the loss tangent remained constant in the frequency range of 10(3) to 10(5) Hz. Different theoretical models were employed to predict the effective dielectric constants of the composite films, and the estimated results were compared with the experimental data. Weibull distribution was used to analyze the dielectric breakdown strength, and the results showed that the breakdown strength decreased then stayed over 60 kV mm(-1).