核-壳结构的硅烷偶联剂交联的SrTiO_3/PVDF复合物薄膜的铁电和介电性能（英文）

Enhanced Dielectric and Ferroelectric Properties of Core-Shell Structure of SrTiO_3/PVDF Composite Films Cross-Linked with Silane Coupling Agent

通过溶液浇筑法制备了核-壳结构的硅烷偶联剂3-氨丙基三乙氧基硅烷(3-APTS)交联的SrTiO_3/PVDF复合物薄膜,对其进行了XRD、FTIR、TG、DSC、SEM、介电和铁电性能测试。研究发现,使用硅烷偶联剂有助于SrTiO_3在复合物薄膜中实现均匀分散,其可能与硅烷偶联剂可以被用作交联剂连接聚合物和无机材料形成核-壳结构有关。SrTiO_3(ST)的引入有助于提高复合物薄膜的结晶性,但是会导致电活性β-晶相含量的轻微减少。当ST的质量含量达到30%时,复合物薄膜的介电常数可以增大至纯PVDF的2.5倍,并且不会引起介电损耗的明显增加;同时,该复合物薄膜的剩余极化率(Ps)也可以增大到原来的2倍左右。我们的研究表明,在PVDF中引入硅烷偶联剂表面改性的ST是制备具有良好分散性的复合物薄膜以及提升其铁电和介电性能的一种有效方法。

Core-shell structure of SrTiO3/PVDF composite films cross-linked with silane coupling agent 3-aminopropyltriethoxysilane（3-APTS） were prepared by solution casting method and characterized by XRD, FTIR,TG, DSC, SEM, dielectric and ferroelectric test. SrTiO3（ST） can be homogeneously distributed into PVDF matrix without obvious agglomeration in the presence of silane coupling agent, which may be related to the formation of core-shell structure in which 3-APTS acts as a cross-linker between polymer and inorganic material. The introduction of ST is helpful to improve the crystallinity, but will lead to a slight decrease in the electroactive β-phase content of composite films. The dielectric constant of composite film will increase up to 2.5 times larger than that of neat PVDF when the mass content of ST is up to 30%, and without leading to obvious increase of dielectric losses. Meanwhile, the Psvalue of this film is increased up to about two times larger than that of pure PVDF. Our study suggests that the incorporation of surface modified ST into PVDF matrix is a useful way to obtain well dispersed film and improve its dielectric and ferroelectric property.