Phase evolution and broadband electromagnetic wave absorption mechanisms of electrospun polymer-derived SiC-based fibrous ceramic membranes

Polymer-derived SiC-based  ceramic fibrous membranes have attracted increasing attention as lightweight and thermally stable electromagnetic wave absorbers. However, simultaneously achieving strong attenuation capability and good impedance matching remains challenging due to the limited regulation of phase composition and dielectric behavior. In this work, multiphase SiC-based fibrous membranes were prepared by electrospinning combined with polycarbosilane (PCS)-derived ceramic conversion. The phase evolution, fiber morphology, dielectric response, and electromagnetic wave absorption performance were regulated by tuning the PCS content and pyrolysis temperatures. Advanced characterizations confirm the formation of a heterogeneous β-SiC/SiO_xC_y/carbon multiphase structure with good flexibility, which provides abundant polarization centers, moderate conductive pathways, and multiple reflection sites, thereby enabling balanced impedance matching and dielectric loss. Consequently, the sample with a PCS content of 1.4 g pyrolyzed at 1400 °C achieves a minimum reflection loss (RL_min) of −27.12 dB at a matching thickness of 2.2 mm and a maximum effective absorption bandwidth (EAB) of 8.22 GHz at 2.7 mm, covering 9.78-18 GHz. Radar cross-section (RCS) simulation further verifies the electromagnetic scattering suppression capability of the optimized fibrous ceramic coating. Therefore, this study provides a useful strategy for tailoring phase composition and dielectric behavior in polymer-derived SiC-based fibrous membranes for broadband electromagnetic wave absorption.