Multilayer composites containing anisotropic structured aerogels: A strategy for enhancing the electromagnetic shielding absorption mechanism and achieving multi-functional integration

Abstract

Multifunctional composite materials have shown great potential in addressing emerging fields such as electromagnetic radiation pollution. By designing a reasonable scheme and arranging the distribution of conductive multiwalled carbon nanotubes (MWCNT) and liquid metal (LM), a multifunctional composite material with conductivity gradient is constructed.We successfully developed a multilayer shielding composite material (C X1 C X2 M Y ) that meets the design requirements using simple freeze-drying technology, solution casting method, and coating technology. The composite material constructs a sequence of multilayer shielding network structures, allowing the electromagnetic wave to undergo a specific "absorptionreflection-reabsorption" process, effectively reducing the reflection of electromagnetic waves and achieving good electromagnetic interference shielding effect (EMI SE). At the X-band, when the absorptivity (A) value is 0.82, the composite material can achieve an EMI SE of 35.74 dB, and when the A value is 0.36, it can achieve 67.17 dB, demonstrating excellent electromagnetic shielding performance. The composite material has excellent mechanical properties and electrical properties. Effective Joule heating effect can achieve high temperature performance of 80 °C at a low voltage of 3 V. The sensitive pressure sensing effect can achieve a resistance change ratio of 558 % under slight pressure. This composite material provides a promising solution for multifunctional integrated electromagnetic interference shielding.