Fabrication of wrinkled carbon microspheres and the effect of surface roughness on the microwave absorbing properties

In this work, we first thoroughly probed the structure-activity relationship between the wrinkled degree of microsphere and the microwave absorption performance. Wrinkled carbon microspheres were fabricated through soap-free living/controlled radical emulsion polymerization and interfacial initiated emulsion polymerization followed by a carbonization process. Tuning the polymerization reaction time, carbon microspheres with different wrinkled degree were obtained. The results confirmed that the wrinkled degree had a significant impact on the absorption performance. As the polymerization time and absorber loading were 8 h and 50%, the wrinkled carbon microspheres showed superior application performance. The reflection loss was −49.45 dB with a thickness of 1.9 mm, and the effective absorption bandwidth was 4.75 GHz. The maximum effective absorption bandwidth could reach 4.84 GHz. Designing rationally the surface microstructure of materials was extremely critical. It provided a new strategy for the improvement of the fixed absorbing materials on microwave absorption performance.