Well-matched impedance of polypyrrole-loaded cotton non-woven fabric/polydimethylsiloxane composite for extraordinary microwave absorption

Abstract Impedance matching characteristic is one of the pivotal elements for fabrication of high-performance electromagnetic wave absorbing materials. In order to optimal impedance matching of the microwave absorbing materials, the Material Genome Initiatives can be expected to rapidly identify optimized components. Herein, the ideal relation between real and imaginary parts of permittivity is established for dielectric loss type microwave absorbing materials, which can provide reliable reference for the fabrication of high-efficiency microwave absorbing materials with matched impedance. Polypyrrole (PPy) and cotton non-woven fabrics (CNFs) were selected as dielectric medium and flexible matrix, and polydimethylsiloxane (PDMS) was introduced through simple vacuum assisted to balance the impedance matching under the guidance of ideal e′-e” relationship. As prepared PPy/CNFs/PDMS composite possesses outstanding absorption performance that the minimum reflection loss (RLmin) reaches −25 dB at the thickness of 4 mm and the effective absorption bandwidth (EAB: RL ≤ −10 dB; > 90% absorption) covers the whole X-band. What's more, the RL of PPy/CNFs/PDMS composite measured by arched reflecting method is consistent with the simulation result by waveguide method, which proves that the model of permittivity attenuation evaluation diagram provides reliable data support for the development of microwave absorption materials in the future.