Simultaneously enhancing the EMI shielding performances and mechanical properties of structure-function integrated CF/PEEK composites via chopped ultra-thin carbon fiber tapes and interfacial engineering with MXene

The functionalization of carbon fiber reinforced poly(ether-ether-ketone) (CF/PEEK) structural composites with high electromagnetic interference shielding efficiency (EMI SE) has important engineering application in the fields of aviation and aerospace. However, the simultaneous enhancement of interfacial properties and EMI SE in the CF/PEEK composite remains a significant concern. To address this issue, we have employed a continuous impregnation approach that involved synthesizing PFEEK as a binder and then utilizing mechanical spreading technology to prepare chopped ultra-thin CF tapes as the reinforcement phase. Subsequently, we deposited 2D MXene (Ti3C2Tx) on the CF tape surface to endow the interface properties and EMI SE for the CF/PEEK composites. As a result, when the MXene content was 1.0 mg/ml, the flexural strength, flexural modulus, and interlaminar shear strength (ILSS) of the obtained CF/PEEK composites achieved 17.6 %, 13.3 % and 36.6 % enhancement higher than that of the virgin CF/PEEK composites, respectively, which may be owing to the elevated interfacial properties via the hydrogen bonds, physical entanglement, it-it interactions, and mechanical interlocking with the incorporation of PFEEK and MXene. The optimal ILSS value and specific EMI SE/t value of the CF/PF-M1/PEEK composites can reach 113.7 MPa and 80.8 dB/mm, respectively. The enhancement in the EMI SE can be attributed to the enhancive reflection, the increased polarization losses, and multiple interlayer reflections of EM waves facilitated by the incorporation of MXene and multi ultra-thin CF/PF-MXene layers. This approach resulted in a structure-function integrated CF/PEEK composite, which holds promising application prospects across various cutting-edge domains.