Synthesis and Electronic Applications of Particle-Templated Ti₃C₂T_zMXene–Polymer Films via Pickering Emulsion Polymerization

Abstract

MXene/polymer composites have gained widespread attention due to their high electrical conductivity and extensive applications, including electromagnetic interference (EMI) shielding, energy storage, and catalysis. However, due to the difficulty of dispersing MXenes in common polymers, the fabrication of MXene/polymer composites with high electrical conductivity and satisfactory EMI shielding properties is challenging, especially at low MXene loadings. Here, we report the fabrication of MXenearmored polymer particles using dispersion polymerization in Pickering emulsions and demonstrate that these composite powders can be used as feedstocks for MXene/polymer composite films with excellent EMI shielding performance. Ti 3 C 2 T z nanosheets are used as the representative MXene, and three different monomers are used to prepare the armored particles. The presence of nanosheets on the particle surface was confirmed by X-ray photoelectron spectroscopy and scanning electron microscopy. Hot pressing the armored particles above T g of the polymer produced Ti 3 C 2 T z /polymer composite films; the films are electrically conductive because of the network of nanosheets templated by the particle feedstocks. For example, the particle-templated Ti 3 C 2 T z / polystyrene film had an electrical conductivity of 0.011 S/cm with 1.2 wt % of Ti 3 C 2 T z , which resulted in a high radio frequency heating rate of 13−15 °C/s in the range of 135−150 MHz and an EMI shielding effectiveness of ∼21 dB within the X band. This work provides a new approach to fabricate MXene/polymer composite films with a templated electrical network at low MXene loadings.

Advances in the Chemical Stabilization of MXenes

“…Around 40 different MXenes have been discovered to date, with more being regularly created, given the array of possible compositions and solid solutions. 3 Due to their properties such as hydrophilicity, colloidally stability, high electrical conductivity, pseudocapacitance, and high Young's modulus, MXenes have shown potential for applications such as energy storage, 4 electromagnetic interference shielding, 5,6 humidity sensing, 7 inks, 8 catalysis, 9 and carbon capture. 10 MXene synthesis is generally carried out by a wet etching approach (Figure 1).…”

“…The nanosheets in the supernatant are collected for further processing in functional coatings, thin films, composites, and so forth. 6 This has been particularly successful for Ti 3 C 2 T z .…”

“…The delaminated dispersion is centrifuged to separate the unexfoliated or partially etched MXene and other heavier components. The nanosheets in the supernatant are collected for further processing in functional coatings, thin films, composites, and so forth . This has been particularly successful for Ti 3 C 2 T z .…”

Thermal Stability and Flammability Studies of MXene–Organic Hybrid Polystyrene Nanocomposites

“…In addition, the pronounced peak (002) shifted from a 2 θ angle of 9.6° to a lower 2 θ angle of around 6.5°, which is typical for Ti 3 C 2 T x nanosheets [ 31 , 32 ]. The Supplementary Material includes the AFM image ( Figure S1 ) of Ti 3 C 2 nanosheets, with a thickness of ∼1.6 nm, indicating single-layer nanosheets [ 33 ]. Furthermore, the XRD pronounced peak (002) shifts to a lower 2 θ angle (4.3°) after the organic functionalization (blue line).…”

Tuning the Self-Assembled Morphology of Ti3C2Tx MXene-Based Hybrids for High-Performance Electromagnetic Interference Shielding

“…Additionally, low-density porous MXene-based EMI shields have been mostly prepared by unidirectional freeze-casting, − hydrazine-assisted foaming, using polymer beads or sponges as the template, − and freeze-drying the MXene/hydrophilic polymer mixtures. − Inevitably, lowering the density of MXene macrostructures by introducing the free volume decreases the electrical conductivity and, consequently, the ohmic loss. However, this can be compensated by other absorption mechanisms, such as interfacial polarization at MXene/air interfaces and enhanced internal reflections due to porosity.…”