Towards suppressing dielectric loss of GO/PVDF nanocomposites with TA-Fe coordination complexes as an interface layer

In this work, graphene oxide (GO) nanosheets with surface modification by Tannic and Fe coordination complexes (TA-Fe) were incorporated into poly(vinylidene fluoride) (PVDF) to prepare high constant but low loss polymer nanocomposites, and the effect of TA-Fe interlayer on dielectric properties of the GO@TA-Fe/PVDF nanocomposites was investigated. The results indicate that the dosage, mixing ratio, and reaction time of TA-Fe complexes have obvious influences on the dielectric properties of the nanocomposites. Furthermore, the TA-Fe interlayer significantly influences the electrical properties of GO@TA-Fe nanoparticles and their PVDF composites, and the GO@TA-Fe/PVDF composites exhibit superior dielectric properties compared with raw GO/PVDF. Dielectric losses of the GO@TA-Fe/PVDF are significantly suppressed to a rather low level owing to the presence of TA-Fe layer, which serves as an interlayer between the GO sheets, thus preventing them from direct contacting with each other. Additionally, the dynamic dielectric relaxation of the GO/PVDF and GO@TA-Fe/PVDF nanocomposites was investigated in terms of temperature.