Ultra-Flyweight Cryogels of MXene/Graphene Oxide for Electromagnetic Interference Shielding

MXene and graphene cryogels have demonstrated excellent electromagnetic interference (EMI) shielding effectiveness due to their exceptional electrical conductivity, low density, and ability to dissipate electromagnetic waves through numerous internal interfaces. However, their synthesis demands costly reduction techniques and/or pre-processing methods such as freeze-casting to achieve high EMI shielding and mechanical performance. Furthermore, limited research has been conducted on optimizing the cryogel microstructures and porosity to enhance EMI shielding effectiveness while reducing materials consumption. Herein, a novel approach to produce ultra-lightweight cryogels composed of Ti3C2Tx/graphene oxide (GO) displaying multiscale porosity is presented to enable high-performance EMI shielding. This method uses controllable templating through the interfacial assembly of filamentous-structured liquids that are readily converted into EMI cryogels. The obtained ultra-flyweight cryogels (3-7 mg cm(-3)) exhibit outstanding specific EMI shielding effectiveness (33 000-50 000 dB cm(2) g(-1)) while eliminating the need for chemical or thermal reduction. Furthermore, exceptional shielding is achieved when the Ti3C2Tx/GO cryogels are used as the backbone of conductive epoxy nanocomposites, yielding EMI shielding effectiveness of 31.7-51.4 dB at a low filler loading (0.3-0.7 wt%). Overall, a one-of-a-kind EMI shielding system is introduced that is readily processed while affording scalability and performance.