Plate-barrier architecture of rGO-TiO2 derived from MXene for constructing well-aligned polymer nanocomposites with excellent dielectric performance

Dielectric polymers are playing increasingly important roles in advanced electronics and electric power systems, because of their high dielectric strength, stability, and lightweight. However, the relatively low intrinsic dielectric constant of dielectric polymers hinders their further applications. Herein, dielectric polymer composites were fabricated by blending with plate-barrier architecture fillers, which are comprised of reduced graphene oxide (rGO) and intercalated titanium dioxide (TiO2) cubes. TiO2 cubes are homogeneously and controllably integrated onto rGO nanosheets utilizing 2D transition metal carbides (MXene) by means of shape match. TiO2 cubes could serve as joints to anchor rGO nanosheets for more effective polarization, and as barriers to impede the conductive contact of rGO nanosheets. In the nanocomposites, rGO nanosheets possess high alignment and overlap area resorting to the anchoring effect of TiO2, which increases the micro-capacitors in series that greatly enhance the dielectric constant. Therefore, it is investigated that the nanocomposites exhibit a high dielectric constant (211) and ultralow dielectric loss (0.104). Moreover, the enhancement mechanism of the micro-capacitors was also revealed by the finite element simulation. This contribution provides a novel strategy to fabricate well-aligned nanocomposites that are promising in electronics flexible materials. MXene derived TiO2 cubes can serve as dielectric mediums and supporting barriers between rGO layers to form well-aligned micro-capacitors, which enable the PVDF nanocomposites to achieve excellent dielectric performance. [Display omitted]