Robust MXene Nanosheet-Based Electromagnetic Interference Shielding Membrane with Cation- Interactions

Electromagnetic interference (EMI) shielding is vital for electronic device reliability and combating electromagnetic wave (EMW) pollution. In this research, we employed a vacuum-assisted filtration method to fabricate MXene membranes and achieved the construction of robust PAA/MXene hybrid membranes by incorporating a polyamic acid (PAA) adhesive containing imidazole rings through cation-pi interactions. The integration of PAA led to a reduction in internal pores and the thickness of the MXene membrane, mainly attributed to the reinforcing cation-pi interactions that enhance the interlayer forces among the MXene nanosheets. This integration substantially enhances the tensile strength of MXene membranes and concurrently induces alterations in their fracture behavior. Adding a small amount of PAA greatly increased conductivity in the PAA/MXene hybrid membrane, but excessive amounts resulted in a severe decline. When PAA content remained below 2 wt % of MXene nanosheets, the EMI SET of the PAA/MXene hybrid membrane exhibited minimal fluctuations, consistently exceeding 60 dB. The EMI shielding mechanism of the PAA/MXene hybrid membrane primarily relied on reflection, with reflected electromagnetic waves accounting for over 60% of the incident EMWs. The utilization of cation-pi interactions in this approach significantly enhances the interface of MXene nanosheets, thereby holding immense potential for the advanced modification of MXene materials.