Effectively tuning electromagnetic absorption of carbon-based nanocomposites by phase transition

Tunable electromagnetic wave absorbing materials (EWAMs) are in increasing demand due to ever-increasing requirement of electromagnetic compatibility. However, the reflection loss could not be adjusted once the traditional EWAM is fixed. Here, we report a novel carbon-based nanocomposite foam with effectively tuning electromagnetic absorption by phase transition of (C₄H₁₀N)MnCl₃. Under the external stimulation of temperature field, the phase in (C₄H₁₀N)MnCl₃ gets changed, leading to tremendous alteration of permittivity. The maximum ε′ and ε'' values of the nanocomposites are able to be tuned up to 60.5% and 158.8%. Moreover, the modification of permittivity ensures the effectively tuning electromagnetic absorption. The nanocomposite exhibits a freely manipulated range of intensity of the strongest reflection loss (ΔRL_min) from 0.31 to 18.00 dB during external field, with the adaptable expansion of the effective absorption bandwidth up to 7.51 GHz. Furthermore, when the ratio of the phase-transition material to the carbon frame is optimized, diversified absorbing modes could be generated to meet the needs of various application scenarios.