Enhanced dielectric constant and suppressed electrical conductivity in polymer nanocomposite films via loading MXene/TiO2/MoS2 nanosheets

Conductor/polymer nanocomposites can achieve high dielectric constant with low filler loading, but conductive fillers come into contact with each other easily, resulting in the formation of conductive paths. In this work, MXene/TiO2/MoS2 nanosheets were prepared by one-step hydrothermal method, and MXene/TiO2/MoS2/poly (vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) nanocomposite films were prepared by solution casting method. At 1 kHz, with an optimized MXene/TiO2/MoS2 nanosheets loading of 8.0 wt%, MXene/TiO2/ MoS2/P(VDF-HFP) nanocomposite films achieve a high dielectric constant of 944 and maintain a low dielectric loss of 0.19. TiO2 and MoS2 semiconductive layers on the surface of MXene nanosheets can prevent the formation of conductive paths, and therefore, nanocomposite films possess suppressed electrical conductivity. Moreover, MXene/TiO2/MoS2 nanosheets can build more microcapacitor structures in nanocomposite films with higher filler loading, which further improves the dielectric constant of nanocomposite films. Finite element simulation shows that TiO2 and MoS2 semiconductive layers can lower the electric field intensity and polarization intensity at the interface between conductive fillers and polymer matrix. Herein, MXene/TiO2/MoS2/P(VDF-HFP) nano composite films possess not only excellent dielectric properties, but also excellent mechanical properties, which can be used as flexible dielectric materials in electronic packaging technology.

Automated summary

In this study, MXene/TiO2/MoS2 nanosheets were prepared using a one-step hydrothermal method, and MXene/TiO2/MoS2/P(VDF-HFP) nanocomposite films were prepared by solution casting method. The optimized nanocomposite films exhibited a high dielectric constant and low dielectric loss, with suppressed electrical conductivity. Additionally, the presence of MXene/TiO2/MoS2 nanosheets allowed for the construction of more microcapacitor structures in the nanocomposite films, further improving the dielectric constant. Finite element simulation results showed that the semiconductive layers of TiO2 and MoS2 could reduce the electric field and polarization intensity at the interface between the conductive fillers and polymer matrix. These MXene/TiO2/MoS2/P(VDF-HFP) nanocomposite films possessed excellent dielectric and mechanical properties, making them suitable for use as flexible dielectric materials in electronic packaging technology.