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 epsilon' and epsilon '' 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 (Delta RLmin) 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. (C) 2022 Elsevier Ltd. All rights reserved.