A Multi‐Functional Foam with an Integrated Antique Square Pedestal Structure Exhibiting Broadband and Stable Microwave Absorption Performance

Abstract A multifunctional absorbing foam (CIPs‐COP/CNTs/PDMS) is fabricated via a simple template casting method, employing mesoporous carbonyl iron (CIPs) and carbonized orange peel (COP) as absorbing agents, along with flexible PDMS modified by CNTs serving as the matrix material. An elaborate design in the work is that a nano‐micron hierarchical rough structure is constructed via coating CNTs on foam surface, aiming to harvest synergistic effect of hydrophobicity and absorbing performance, where the contact angle is 136.2° and reflection loss (RL _min ) reaches −48.2 dB. The absorbing stability and resistance sensitivity are investigated. The results manifest that CIPs‐COP/CNTs/PDMS foam exhibits highly sensitive resistance responses to force, including strength and direction. The foam's RL _min values remain nearly unchanged at ‐46.0 dB after 365 days of exposure to atmosphere, indicating a steady absorption properties. Significantly, to broaden the absorption bandwidth, tri‐layer square pedestal foam is assembled, the integrated structure feature is similar to ancient architecture, achieving RL _min of −52.0 dB and broadband of 12.5 GHz, covering full of Ku and X bands, and part of C band. The CIPs‐COP/CNTs/PDMS foam is expected to become a multi‐function material for outdoor application due to its hydrophobicity, machine‐electricity sensitivity, and stable absorbing properties.