MXene@c-MWCNT Adhesive Silica Nanofiber Membranes Enhancing Electromagnetic Interference Shielding and Thermal Insulation Performance in Extreme Environments

A lightweight flexible thermally stable composite is fabricated by combining silica nanofiber membranes (SNM) with MXene@c-MWCNT hybrid film. The flexible SNM with outstanding thermal insulation are prepared from tetraethyl orthosilicate hydrolysis and condensation by electrospinning and high-temperature calcination; the MXene@c-MWCNT_x:y films are prepared by vacuum filtration technology. In particular, the SNM and MXene@c-MWCNT_6:4 as one unit layer (SMC₁) are bonded together with 5 wt% polyvinyl alcohol (PVA) solution, which exhibits low thermal conductivity (0.066 W m^-1 K^-1) and good electromagnetic interference (EMI) shielding performance (average EMI SE_T, 37.8 dB). With the increase in functional unit layer, the overall thermal insulation performance of the whole composite film (SMC_x) remains stable, and EMI shielding performance is greatly improved, especially for SMC₃ with three unit layers, the average EMI SE_T is as high as 55.4 dB. In addition, the organic combination of rigid SNM and tough MXene@c-MWCNT_6:4 makes SMC_x exhibit good mechanical tensile strength. Importantly, SMC_x exhibit stable EMI shielding and excellent thermal insulation even in extreme heat and cold environment. Therefore, this work provides a novel design idea and important reference value for EMI shielding and thermal insulation components used in extreme environmental protection equipment in the future.