Carbon-enriched PDC-SiC with enhanced electromagnetic wave absorption: A study examining the impact of branched molecular chains in precursor

In this work, a novel carbon-enriched SiC by the polymer derived ceramic (PDC-SiC) route was manufactured. By varying the branched chain of the preceramic polymer, the structure and electromagnetic properties of the obtained PDC-SiC ceramics can be effectively altered through carbon enrichment. Specially, PDC-SiC ceramics obtained from branched polysilylacetylene (PSA) constitute a composite material that contains nano-sized SiC grains, carbon nanotubes (CNTs), and silicon carbide nanowires (SiC nw ). Such PDC-SiC ceramics possess a complex three-dimensional network of CNT S /SiC nw , leading to remarkable microwave absorption properties. Notably, the PDC-SiC ceramics processed from dimethyl-polysilylacetylene (D-PSA) achieved a minimum reflection loss (RL min ) of −55.0 dB at 14.4 GHz, and an effective absorption bandwidth (EAB) extends across 5.5 GHz, with a thickness of 2 mm.