Preparation and properties of flexible electromagnetic shielding composites

Although traditional metallic electromagnetic shielding materials have appeared for quite a long time, the defects of high density and poor flexibility have limited their further applications for modern society. Luckily, a flexible rubber stuffed with light conductive materials is promising to solve this puzzlement and hence has attracted much attention. In this paper, a novel kind of flexible electromagnetic shielding material system was invented using cobalt-plated carbon aerogel as a conductive filler in the silicone rubber matrix. With a cobalt content of 30%, the 8-layered composite reveals the tensile strength of the composite is 1.23 MPa, and the fracture elongation is 128.7%. The shielding efficiency was measured to be 11.56 dB, and the electromagnetic wave transmittance of the composite was significantly decreased to less than 10%, indicating that at least 90% of electromagnetic waves can be reflected or absorbed. This excellent electromagnetic shielding performance can be ascribed to a combined action of interlayer multiple reflections, low dielectric loss of carbon aerogel, and low magnetic loss of cobalt particles. In addition, the composite also shows a good hydrophobic and high thermal stability, further extending the application feasibility in complex environments.