Direct Ink Writing of Highly Conductive MXene Frames for Tunable Electromagnetic Interference Shielding and Electromagnetic Wave-Induced Thermochromism

Abstract

Highlights 3D printing of MXene frames with tunable electromagnetic interference shielding efficiency is demonstrated. Highly conductive MXene frames are reinforced by cross-linking with aluminum ions. Electromagnetic wave is visualized by electromagnetic-thermochromic MXene patterns. Abstract The highly integrated and miniaturized next-generation electronic products call for high-performance electromagnetic interference (EMI) shielding materials to assure the normal operation of their closely assembled components. However, the most current techniques are not adequate for the fabrication of shielding materials with programmable structure and controllable shielding efficiency. Herein, we demonstrate the direct ink writing of robust and highly conductive Ti3C2Tx MXene frames with customizable structures by using MXene/AlOOH inks for tunable EMI shielding and electromagnetic wave-induced thermochromism applications. The as-printed frames are reinforced by immersing in AlCl3/HCl solution to remove the electrically insulating AlOOH nanoparticles, as well as cross-link the MXene sheets and fuse the filament interfaces with aluminum ions. After freeze-drying, the resultant robust and porous MXene frames exhibit tunable EMI shielding efficiencies in the range of 25–80 dB with the highest electrical conductivity of 5323 S m−1. Furthermore, an electromagnetic wave-induced thermochromic MXene pattern is assembled by coating and curing with thermochromic polydimethylsiloxane on a printed MXene pattern, and its color can be changed from blue to red under the high-intensity electromagnetic irradiation. This work demonstrates a direct ink printing of customizable EMI frames and patterns for tuning EMI shielding efficiency and visualizing electromagnetic waves.

Porous and Ultra-Flexible Crosslinked MXene/Polyimide Composites for Multifunctional Electromagnetic Interference Shielding

“…Generally, EMI shielding performance of conductive porous composites is influenced by the reflection, absorption, and multi-reflections, corresponding to the mobile charge carriers, electric dipoles, and interior interfaces/surfaces, respectively [19,56,62]. The micrometer-sized pores induced more reflections or scatterings of incident EM waves, which had more interactions with the pore walls in the C-MXene@ PI composite foams, efficiently increasing SE A [16][17][18]63]. The large mismatch of conductivity in the interfaces between the MXene and PI also led to high interfacial polarization [8], which combined with the abundant charge carriers from MXenes [23,63,64], resulting in increased SE A of the pore walls.…”

“…The micrometer-sized pores induced more reflections or scatterings of incident EM waves, which had more interactions with the pore walls in the C-MXene@ PI composite foams, efficiently increasing SE A [16][17][18]63]. The large mismatch of conductivity in the interfaces between the MXene and PI also led to high interfacial polarization [8], which combined with the abundant charge carriers from MXenes [23,63,64], resulting in increased SE A of the pore walls. In addition, the MXene terminal functional groups were considered to give rise to electric dipoles under the electric field of the EM wave [17,22,26], improving the SE A of the MXene-based composites.…”

Self-Assembly 3D Porous Crumpled MXene Spheres as Efficient Gas and Pressure Sensing Material for Transient All-MXene Sensors

“…Gas and pressure sensors made of the same degradable sensing and electrode materials are ideal for achieving full transiency upon only one external trigger. MXenes (Ti 3 C 2 T x ), as a novel class of two-dimensional nanomaterials with rich surface functional groups, have been identified as the sensing layer and electrode due to their high conductivity, excellent signal-tonoise ratio, and abundant hydroxyl on the surface, which is superior to other metal oxides and two-dimensional (2D) materials [11][12][13][14][15][16][17][18]. Meanwhile, because of their chemical instability, MXenes exhibit controllable transiency in H 2 O 2 and NaOH aqueous solutions [19,20].…”

Layered Foam/Film Polymer Nanocomposites with Highly Efficient EMI Shielding Properties and Ultralow Reflection

“…Increasing the electrical conductivity can enhance the EMI SE and EM wave dissipation via conduction loss [ 21 , 50 ]. However, excessively high conductivity can result in high reflectivity because of impedance mismatch [ 60 ].…”