Directional Freezing Fabrication of RSF/PVA/MXene Aerogels: Layered Structure and High-Efficiency Electromagnetic Interference Shielding.

Abstract

The rapid development of wireless communication technologies and electronic devices has intensified electromagnetic interference (EMI) pollution, creating an urgent demand for lightweight and efficient shielding materials. In this work, RSF/PVA/MXene composite aerogels with ordered lamellar structures were fabricated by directional freeze-drying. Directional freeze-drying generated an ordered lamellar architecture, while RSF and PVA facilitated the homogeneous distribution of MXene nanosheets within the aerogel framework. Among the investigated samples, RPM-60 exhibited the maximum shielding effectiveness at 12.4 GHz, corresponding to a shielding efficiency of 99.45%, demonstrating the favorable MXene content for efficient EMI shielding at this frequency. The enhanced shielding performance was mainly attributed to the ordered lamellar structure, which promoted multiple internal reflections, together with conductive loss and interfacial/dipole polarization induced by MXene. These results demonstrate the potential of RSF/PVA/MXene composite aerogels as lightweight bio-based EMI shielding materials.