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MXene has garnered extensive attention in the preparation of polymer dielectric materials due to its outstanding electrical conductivity. However, high dielectric loss has hindered the application of such polymer-based composites. In this study, MXene/PVDF composites were prepared with polyvinylidene fluoride (PVDF) as the matrix and two-dimensional nanosheets (Ti 3 C 2 T x MXene) as fillers. To mitigate dielectric loss, MXene was adorned with a polydopamine (PDA) layer. Results showed that compared to MXene/PVDF composites, MXene@PDA/PVDF composites exhibit lower dielectric loss. At 103 Hz, the dielectric constant of 2 wt% MXene@50%PDA/PVDF composite (50 % PDA relative to the mass of MXene) is 12.8, showing a 1.5-fold that of pure PVDF. However, it boasts a mere dielectric loss of 0.017, signifying a remarkable reduction of 57.4 % when compared to the MXene/PVDF composite. The 12 wt% MXene@25%PDA/PVDF composite (25 % PDA relative to the mass of MXene) demonstrates a dielectric constant of 101.4 at 103 Hz. It boasts a dielectric loss of 0.377, signifying a reduction of 36.1 % compared to the MXene/PVDF composite. Composites with excellent dielectric properties can be prepared by the addition of MXene@PDA into PVDF. [Display omitted] • Incorporation of MXene filler significantly increases the dielectric constant of the PVDF matrix. • PDA-coated MXene disperses more uniformly in the PVDF matrix, enhancing performance. • 2 wt% MXene@50%PDA/PVDF has a dielectric constant 1.5 times that of pure PVDF. • 12 wt% MXene@25%PDA/PVDF composite achieves high dielectric constant and reduced loss. • MXene@PDA/PVDF composites are simple to prepare and have great potential in the field of dielectric materials. [ABSTRACT FROM AUTHOR]

Dielectric composites made using two kinds of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] (70/30 and 80/20 mol%) as polymer matrices and nickel particles coated carbon nanotubes (Ni-CNTs) as filler were developed via solution-processed method. The scanning electron microscopy (SEM) indicated good compatibility and dispersion of Ni-CNTs in the P(VDF-TrFE) matrix. Ni-CNTs/P(VDF-TrFE) composites exhibited high dielectric constants with low dielectric losses. The maximum dielectric constants of Ni-CNTs/P(VDF-TrFE) composites of 198 and 185 at 100 Hz were obtained at 18.0 wt% Ni-CNTs loading, respectively. The incorporation of Ni-CNTs in the P(VDF-TrFE) matrix resulted in enhanced thermal conductivity. The highest values, obtained at 18.0 wt% Ni-CNTs loading, were 1.05 and 1.03 W/m K, respectively. Although there were no very obvious difference, the dielectric properties and thermal conductivity of Ni-CNTs/P(VDF-TrFE) 70/30 mol% composites were slightly better to those of Ni-CNTs/P(VDF-TrFE) 80/20 mol% composites in many cases. The aforementioned results suggest that these high-performance composites hold great promise for application in electrical and electronic field. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride) (PVDF)/poly(methyl methacrylate) (PMMA)/hydroxylated multiwall carbon nanotubes (MWNTs-OH) nanocomposites are prepared via solution blending and hot-press processing. The structure, morphology, crystallization behavior and dielectric properties of nanocomposites are studied. The results show that the crystallization of PVDF is affected by PMMA and MWNTs-OH. With the introduction of PMMA and increment of MWNTs-OH, the content of polar phase in PVDF increases. The dependence of the dielectric properties of the nanocomposites on both volume fraction of the fillers and frequency is investigated. The percolation threshold of the nanocomposite, 2.79 vol.% (volume fraction), is much lower than that of the common two phase particle-polymer composite. A dielectric constant of over 300 is observed at 10 Hz with 3.12 vol.% of MWNTs-OH, which is near the percolation threshold. Large enhancements of the conductivity and loss tangent are also observed near the percolation threshold. The results can be explained by the percolation theory and nanocapacitor model theory. [ABSTRACT FROM AUTHOR]