具有多层结构的聚合物复合薄膜的介电和磁性能

采用旋涂法制备了 Fe3 O4/聚偏氟乙烯(PVDF)复合薄膜(A)、多壁碳纳米管(MWCNT)/PVDF复合薄膜(B)以及纯PVDF薄膜(P)。利用热压法制备具有3层结构的AAA、ABA及APA 复合薄膜。为了探究层状结构对复合薄膜介电和磁性能的影响，制备了单层膜A作为对比(厚度与AAA复合薄膜相同)。分别研究了薄膜的介电和磁性能。结果表明：由于界面效应，同等厚度的AAA复合薄膜较A膜而言具有较高的介电常数；以B和P薄膜替代AAA结构中间层薄膜后，其中ABA复合薄膜的介电常数高于AAA及APA复合薄膜，同时保持较低的介电损耗。对于磁性能，层状结构对复合薄膜的饱和磁化强度及矫顽力均无明显的影响，而ABA复合薄膜的饱和磁化强度高于AAA及APA复合薄膜，且ABA和APA复合薄膜的矫顽力增加。层状结构设计不仅能够调节复合材料的介电性能和磁性能，而且有利于不同纳米填料的分散，为制备多功能聚合物复合材料提供了一定的借鉴作用。

Dielectric and magnetic properties of polymer composite films with multilayered structure

Fe3 O4/poly(vinylidene fluoride)(PVDF)composite films (A),multi-walled carbon nanotubes (MWC-NT)/PVDF composite films (B)and pure PVDF films (P)were prepared by solution casting method.The triple-layer structure composite films of AAA,ABA and APA were prepared by hot pressing method.In order to explore the effect of layer structure on dielectric and magnetic properties of composite films,the single layer A films with the same thickness of AAA composite films were prepared for the comparison.The dielectric and magnetic properties were investigated respectively.The results show that AAA composite films have higher dielectric constant than A films as the same thickness due to the interfacial effect.The replacement of the intermediate of A layer of AAA structure by B and P films cause the dielectric constant of AAA,ABA and APA composite films follows a sequence:ABA>AAA>APA and keep the low dielectric loss.For the magnetic properties,the layered structure has slight effect on the saturation magnetization strength and coercivity of composite films.The saturation magnetization strength of AAA,ABA and APA composite films follows a sequence:ABA>AAA>APA and the coercivity increa-ses in ABA and APA composite films.The layer structure design not only tunes the dielectric and magnetic proper-ties of composites but also benefits dispersion of different nanoparticles.This work demonstrates a reference to pre-pare the multifunction polymer composites.