Constructing hierarchical Ti3SiC2 layer and carbon nanotubes on SiC fibers for enhanced electromagnetic wave absorption

To enhance the absorption performance of silicon carbide fiber (SiCf), hybrid fibers with a double shell structure (Ti3SiC2 and carbon nanotubes (CNTs)) on the SiCf (CNT@Ti3SiC2@SiCf) were successfully synthesized by the combination of molten salt method and floating catalytic chemical vapor deposition. A series of 10% weight fraction fibers reinforced paraffin samples was prepared to study the double coating influences on the electro-magnetic wave (EMW) absorption performances. Coated by Ti3SiC2 and CNTs, the dielectric permittivity of hybrid fibers could be modulated in a quite wide range. The CNT@Ti3SiC2@SiCf with a thickness of 3.8 mm showed a minimum reflection loss value of-53 dB at 6.57 GHz, and the CNT@Ti3SiC2@SiCf with a thickness of 2.5 mm presented a wide effective absorption bandwidth of 5.6 GHz (from 9 to 14.6 GHz). The highly improved EMW absorption performance of CNT@Ti3SiC2@SiCf was attributed to the combination of conductive loss and dielectric loss aroused by interfaces. The excellent absorption performance provided the modified SiCf with a high potential in the application of EMW absorbers.