GO@TA-Fe/PVDF纳米复合材料制备与介电性能

为降低氧化石墨烯（GO）/聚偏氟乙烯（PVDF）体系的介电损耗，本文采用单宁酸-铁配合物（TA-Fe）修饰GO表面，将改性GO和PVDF复合后制得了GO@TA-Fe/PVDF纳米复合电介质材料，研究了GO@TA-Fe对PVDF复合材料的微观形貌及介电性能影响。研究结果表明，TA-Fe包覆层强化了GO与PVDF基体间界面相容性及界面作用力，促进了GO在基体中均匀分散；TA-Fe界面层的存在显著降低了GO/PVDF漏导电流及损耗，归因于绝缘界面层有效阻止了GO之间直接接触，抑制漏导电流；TA-Fe用量对体系介电性能有明显影响，随TA-Fe用量增大，体系的介电损耗和电导率显著降低。与GO/PVDF相比，质量分数2%的GO@TA-Fe/PVDF在100Hz下介电常数为1000，而介电损耗由19.8降低为0.08。本研究制备的高介电常数及低损耗的柔性GO@TA-Fe/PVDF纳米电介质材料在电子器件及电力设备领域具有潜在应用。

Preparation and dielectric properties of GO@TA-Fe/PVDF nanocomposites

To reduce the dielectric loss of graphene oxide (GO)/PVDF(polyvinylidene fluoride) nanocomposites, the tannic acid-iron complexes(TA-Fe) was used to modify the surface of pristine GO, and the modified GO was employed as filler to reinforce PVDF. The effects of GO@TA-Fe on the microstructures and dielectric properties of the PVDF nanocomposites were studied. The results showed that the introduction of the TA-Fe interface layer improved the interfacial compatibility and interactions between the GO and PVDF matrix, promoting the GO homogeneous dispersion in the matrix. The use of TA-Fe interface layer rapidly decreased the dielectric loss and leakage current of the composites because the TA-Fe interface layer effectively prevented direct contact between the GO nanosheets, thus suppressing the leakage current. Further, the TA-Fe dosage had significant effect on the dielectric properties of nanocomposites. The dielectric loss and conductivity decreased remarkably with an increase in TA-Fe loading. The 2% GO@TA-Fe/PVDF exhibited a high permittivity of 1000 at 100Hz and a very low loss of 0.08 compare with 19.8 for the mass fraction 2% GO/PVDF. The prepared flexible GO@TA-Fe/PVDF nanocomposites with high dielectric constant and low loss had potential applications in the field of electronic devices and power equipment.