Two‐dimensional Ti₃C₂T_x/poly(vinylidene fluoride) metacomposites with weakly negative permittivity

Abstract

In recent years, random metacomposites with tunable negative permittivity have aroused widespread attention because of their distinctive properties and broad potential prospects. It is indicated that an enormously negative permittivity with a large value is not conducive to performance optimizing and impedance matching. In this article, the 2D Mxene Ti3C2Tx was selected as the conductive phase instead of metal and carbon materials to fabricate Ti3C2Tx/poly(vinylidene fluoride) metacomposites. The results of dielectric properties indicated that the conductive Ti3C2Tx networks were formed by Ti3C2Tx contacting with each other near the percolation threshold (ƒc). The as‐obtained metacomposites containing 75 wt% Ti3C2Tx generated percolating phenomenon. Additionally, when the fraction of Ti3C2Tx was below ƒc, the frequency dispersion behaviors of conductivity were in accordance with the Jonscher's power law, which proved that conducting mechanism was dependent on hopping conduction. While above ƒc, the conductivity conformed to the Drude model and Lorentz model, which demonstrated a conductive behavior. Furthermore, the real part of permittivity transformed to negative value at 75 wt%, which can be explained as the existence of the low‐frequency plasma oscillation and electric‐dipole‐induced resonance. The dielectric loss of the metacomposite was also analyzed by the imaginary permittivity spectra. Small negative permittivity values in the range of −550 to −400 were observed, owing to the low free carrier concentration in composites. The appearance of weakly negative permittivity opened up a new direction in negative dielectric materials by 2D layered Ti3C2Tx nanomaterials.

Recent Advances of Wearable Antennas in Materials, Fabrication Methods, Designs, and Their Applications: State-of-the-Art

“…Recently, a new Ti3C2Tx/PVDF metacomposite with a negative permittivity (−550 to −400) and polymer-zirconia nanocomposite has aroused great attention due to their unique properties. It has opened new directions in the field of wearable applications [ 150 , 151 ]. In addition, new composite materials, such as a graphene oxide layer combined with poly 3,4-ethylenedioxythiophene: polystyrene sulfonate (PEDOT: PSS), can be utilized [ 152 ].…”

High‐dielectric PVDF/MXene composite dielectric materials for energy storage preparation and performance study

“…22 Zhang et al fabricated Ti3C2Tx/poly (vinylidene fluoride) metacomposites and considered the appearance of weakly negative permittivity opened up a new direction in negative dielectric materials by 2D layered Ti3C2Tx nanomaterials. 23 Pan et al obtained PVA/MXene nanocomposites via casting/evaporation method, improving the flame retardancy, thermal and mechanical properties of PVA. 24 Donthula et al prepared a ternary composite as high-performance supercapacitor electrodes by depositing polyaniline (PANI) onto electrospun MXene-embedded carbon nanofibers (CNF).…”

“…In recent years, they have been used in wastewater treatment 21 and photocatalytic degradation of organic matter 22 . Zhang et al fabricated Ti3C2Tx/poly(vinylidene fluoride) metacomposites and considered the appearance of weakly negative permittivity opened up a new direction in negative dielectric materials by 2D layered Ti3C2Tx nanomaterials 23 . Pan et al obtained PVA/MXene nanocomposites via casting/evaporation method, improving the flame retardancy, thermal and mechanical properties of PVA 24 .…”

Low‐loss percolative epsilon‐negative composites derived from the ultra‐low percolation threshold

“…[1,2] Different with periodic units, the percolation structures were easier to be tailored and exhibited multiple applications. [3][4][5][6][7] In general, a novel property of negative permittivity along with lower losses could be depended on the distributions of conductive fillers, which is relied on the construction of percolation networks, also known as percolation phenomena. [8][9][10] It is reported that when the conductive fillers content exceeds the f c , the positive permittivity can be transformed into a negative permittivity in the entire frequency range, accompanied by the formation of percolative networks.…”