Phase Evolution and Broadband Electromagnetic Wave Absorption Mechanisms of Electrospun Polymer-Derived SiC-Based Fibrous Ceramic Membranes
Polymer-derived SiC-based ceramic fibrous membranes are lightweight, thermally stable electromagnetic wave absorbers, but simultaneously achieving strong attenuation and good impedance matching remains difficult due to limited control over phase composition and dielectric behavior. This work prepares multiphase SiC-based fibrous membranes by electrospinning combined with polycarbosilane (PCS)-derived ceramic conversion. Phase evolution, fiber morphology, dielectric response, and electromagnetic wave absorption are regulated by tuning PCS content and pyrolysis temperature. Advanced characterization confirms a heterogeneous β-SiC/SiOxCy/carbon multiphase structure with good flexibility, providing abundant polarization centers, moderate conductive pathways, and multiple reflection sites, thereby balancing impedance matching and dielectric loss. The sample with 1.4 g PCS pyrolyzed at 1400 °C achieves a minimum reflection loss (RLmin) of −27.12 dB at 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 simulation verifies electromagnetic scattering suppression of the optimized fibrous ceramic coating. This study provides a strategy for tailoring phase composition and dielectric behavior in polymer-derived SiC-based fibrous membranes for broadband electromagnetic wave absorption.