Effects of particle size on the dielectric properties of polymer matrix flexible nanocomposites were studied. Synthesized barium titanate (BaTiO3; BT) nanoparticles (NPs) with different sizes were effectively dispersed in the matrix polymer using a simple phase separation method. The dielectric responses of free-standing thin composite films were studied by impedance spectroscopy. The interactions between nanoparticles were also studied by finite element analysis and compared with experimental data using a time harmonic-electric current solver in the AC/DC module of COMSOL Multiphysics® 5.2. The dielectric permittivity of polymer matrix nanocomposites was remarkably affected by the BT particle size, while the dielectric loss did not show any noticeable changes. The real permittivity exhibited the highest value when the BT particle size was near 100 nm. The calculated energy density based on measured real permittivity and breakdown strength was as high as 17.24 J/cm3. The dielectric properties of polymer matrix nanocomposites can be improved by controlling the particle size of nanofillers in conjunction with surface treatment of fillers.

中文翻译：

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纳米粒子尺寸和相互作用对聚合物基柔性介电纳米复合材料介电性能的影响

研究了粒径对聚合物基柔性纳米复合材料介电性能的影响。使用简单的相分离方法，合成的钛酸钡（BaTiO3；BT）纳米颗粒（NPs）具有不同的尺寸，有效地分散在基体聚合物中。通过阻抗谱研究了自支撑薄复合膜的介电响应。还通过有限元分析研究了纳米粒子之间的相互作用，并使用 COMSOL Multiphysics® 5.2 的 AC/DC 模块中的时间谐波-电流求解器与实验数据进行了比较。聚合物基纳米复合材料的介电常数受 BT 粒径的显着影响，而介电损耗没有表现出任何明显的变化。当 BT 粒径接近 100 nm 时，实际介电常数表现出最高值。根据测量的实际介电常数和击穿强度计算出的能量密度高达 17.24 J/cm3。聚合物基质纳米复合材料的介电性能可以通过控制纳米填料的粒径以及填料的表面处理来提高。