Dielectrical properties of Graphite Nanosheets/PVDF Composites Regulated by Coupling agent

Publication date: Available online 15 October 2019Source: Materials Today CommunicationsAuthor(s): Xue Li, Xiaoming Wang, Ling Weng, Yang Yu, Xiaorui Zhang, Lizhu Liu, Cheng WangAbstractnanosheets (GNs) with different coupling agents to enhance the dielectric properties of GNs/PVDF composite membranes, and the modified results were characterized by FT-IR. The dielectrical properties and the breakdown field strength of composites film was characterized. The results indicated that the dielectric constant of the composite increases, with the increasing of GNs volume fraction. Moreover, the coupling agent modifies the GNs to confine the carriers of the GNs, which reduces the dielectric loss and increases the breakdown field strength. Since PFOES contains C-F, higher affinity for PVDF leads to higher dielectric constant, and modification of GNs with PFOES and KH570 improves the compatibility of GNs and PVDF, which leads to higher breakdown field strength. When the graphite nanosheets (5 wt%) was modified with coupling agent KH570, the dielectric constant was increased by an order of magnitude to 167 compared with PVDF, the breakdown field strength was also increased to 85.39 kV/mm, and the storage density reached 5.37655. J/cm3; when used PFOES modified graphite nanosheets, the dielectric constant was as high as 295 when the amount was 5 wt%, and the breakdown field strength was increased to 68.64 kV/mm, which is 3.3 times that of pure PVDF. The storage density is 6.13691â...
Source: Materials Today Communications - Category: Materials Science Source Type: research