Sandwich nanoarchitectonics of heterogenous CB/CNTs honeycomb composite for impedance matching design and microwave absorption.

Sandwich structure composite is one of the most potential and effective materials to comprehensively realize microwave absorption in wide frequency range and structural lightweight function. Here, honeycomb (HC) composites were fabricated by immersion method, consisting of a carbon nanotubes/carbon black/polyurethane (CNTs/CB/PU) absorbing layer and an aramid HC core. The using CNTs and CB were both modified by improved Hummers method with a heterogeneous structural surface to enhance the dielectric properties of the carbon materials. The sandwich honeycomb (SHC) absorber showed excellent broadband absorption performance with an effective absorption bandwidth (RL<−10 dB) of 15.5 GHz. Furthermore, the compressive stress of the absorber reached 3.69 MPa. With the integrated high microwave absorption and load-bearing performance, the as-prepared SHC absorber demonstrated promising future for applications in avionics. [Display omitted] • The SHC absorber exhibited excellent absorption and comprehensive properties. • Maxwell-Garnett formula was modified by a coefficient to fit honeycomb structure. • Multilayer impedance matching was realized using Jaumamn structure design method. • The EAB of 15.5 GHz was due to heterogenous CNTs/CB and impedance matching. [ABSTRACT FROM AUTHOR]