A strong insulating, compressible Nd2O3@CNFs WPU foam for robust electromagnetic wave absorption

Abstract

The portable fabrication of multifunctional, lightweight, and ultra-wide absorption bandwidth electromagnetic wave absorbing materials remains a significant challenge. In this study, both component modulation and architecture design were simultaneously employed to construct a layered porous electromagnetic wave absorbing foam (EMAF) with Nd2O3@CNFs as the backbone and waterborne polyurethane (WPU) and starch as the cross-linking agents. Due to the rich heterogeneous interfaces brought by multiple components and the electromagnetic coupling structure of Nd2O3@CNFs, EMAF-4 exhibits an ultra-wide effect absorption bandwidth (EAB) of 9GHz and a minimum Reflect Loss (RL) of -52.33dB. Furthermore, the layer structure of the foam enables the sample to rebound quickly when subjected to stress. The porous architecture effectively blocks heat conduction and radiation, resulting in an ultra-low thermal conductivity (0.036W/(m·K)), which enables the material to realize dual microwave-infrared stealth at the same time. This work provides new ideas and broaden the applications for multifunctional microwave absorbing materials.