KNN/PVDF纳米复合膜的制备及介电性能研究∗

摘要

采用聚合物前驱体法合成了 K0．5 Na0．5 NbO3(KNN)纳米粉体.X 射线衍射(XRD)和扫描电子显微镜(SEM)分析表明,制备出的 KNN 粉体为单一的纯钙钛矿结构,并且其晶粒尺寸在15~25 nm 之间.采用溶液混合法制备了 KNN/聚偏氟乙烯(KNN/PVDF)纳米复合膜,研究了 KNN 纳米粉体的含量对复合膜微观形貌和介电性能的影响.结果表明,KNN纳米粉体均匀地分散在聚偏氟乙烯(PVDF)基体中, KNN/PVDF复合膜材料的介电常数和介电损耗均随着KNN含量的增加而增加.在1 kHz下,当KNN质量分数为20％时,复合膜的介电性能较为优越,其介电常数为29．9,介电损耗为0．053.%K0.5 Na0.5 NbO3 (KNN)nanoparticles were prepared by polymeric precursor method.X-ray diffraction (XRD)and scanning electron microscopy (SEM)show that the KNN particles possess pure perovskite struc-tures and the crystalline size is 15-25 nm.It was accessible that KNN/Polyvinylidene fluoride (KNN/PVDF) composite membranes were fabricated using the method of solution mixing.The SEM images of the composite membranes display that the KNN nanoparticles are dispersed homogeneously in the PVDF matrix.The effect of content of KNN particles in the composite membranes on its morphology and dielectric property has been inves-tigated.The dielectric constant and dielectric loss of the composite membranes increase with increasing content of KNN particles.When the KNN nano-powder content is 20wt%,the composite membrane shows excellent di-electric properties with a dielectric constant of 29.9 and the dielectric loss of 0.053 at 1 kHz.