Enhancement of dielectric properties in flexible Ti3C2Tx/PVDF composite films

Ti3C2Tx MXene has gained increasing research in high dielectric materials. In this study, Ti3C2Tx nanosheets were incorporated as conductive filler into the PVDF matrix and Ti3C2Tx/PVDF composite films were prepared by an easy solution-casting method. The prepared Ti3C2Tx nanosheets with large aspect ratios were confirmed by XRD, SEM and TEM. The effects of various Ti3C2Tx nanosheets loadings on the morphology, crystallization behaviour and dielectric properties of Ti3C2Tx/PVDF composite films were explored and the mechanism of dielectric properties was explained using an equivalent circuit model. The results showed that a high dielectric permittivity of 155 accompanied by a low dielectric loss of 0.32 at 1 kHz was obtained in the Ti3C2Tx/PVDF composite film with 13 wt% Ti3C2Tx loading. With up to near the percolation limit of 15 wt% Ti3C2Tx loading (fc = 15.9 wt%), the dielectric permittivity increased to 762. The enhanced dielectric properties are mainly caused by the strong interfacial polarization and micro-capacitance effect, as well as good interfacial compatibility between Ti3C2Tx nanosheets and PVDF matrix. This work will provide a promising composite in modern electronic fields.