Ambient‐Pressure‐Dried Aerogel Amplifies Interfacial Polarization Toward High‐Efficiency Microwave Absorption

Abstract The existing polarization loss‐dominated electromagnetic wave (EMW) absorbing materials are predominantly composed of powders, however, the challenges of efficiently dispersing powders in matrix exist, the realization of structurally and functionally integrated EMW absorber, governed by polarization loss remains a challenge. Herein, a type of ambient‐pressure‐dried (APD) anisotropic aerogels is prepared exhibiting abundant, multiscale involving nanoscale to microscale interfaces by utilizing 1D cellulose nanofibers (CNF) and 2D conductive multilayer graphene (MGr). Consequently, the interfacial polarization effect is significantly amplified, contributing to the polarization‐dominated EMW loss mechanism of new structure‐functionally integrated EMW absorption aerogels. Such aerogels showcase high‐efficiency EMW absorption performance involving a minimal reflection loss of −51.48 dB and an effective absorption bandwidth of 5.52 GHz, comparable to the best EMW absorption monoliths. Moreover, the influence rules of interfacial polarization on EMW absorption performance are summarized, which can make a guidance to the design of frequency selective EMW absorbing materials. Combined with the energy‐efficient, green, scalable, and large‐area APD preparation strategy, this study develops a facile design strategy for polarization‐dominated structure‐functionally integrated EMW absorber.