Achieving high-performance and tunable microwave shielding in multi-walled carbon nanotubes/polydimethylsiloxane composites containing liquid metals

In this study, multi-walled carbon nanotube-filled polydimethylsiloxane (CNT/PDMS) composites with highperformance and tunable microwave shielding were prepared via the incorporation of liquid metals (LMs). First, the CNT particles were well dispersed in the PDMS pre-polymer through ultrasound assistance. Second, the LM and curing agents were added to the CNT/PDMS mixture with manual stirring to obtain a uniform CNT/LM/ PDMS mixture. This was followed by curing to produce the final CNT/LM/PDMS composites. The highperformance microwave shielding ability of the composites was ascribed to a synergistic effect between the nanoscale CNTs and microscale LM particles. Specifically, a microwave shielding effectiveness (SE) of 42.6 dB was achieved by the composites which contained 2.5 vol.% LM and 3.0 vol.% CNT particles. Furthermore, the composites exhibited high absorption loss and low reflection loss, which could effectively reduce secondary microwave pollution. More importantly, the microwave shielding performance of the composites containing LMs could be regulated by compression owing to the formation of cracks and the coalescence of the LM particles.

Automated summary

In this study, multi-walled carbon nanotube-filled polydimethylsiloxane (CNT/PDMS) composites with high-performance and tunable microwave shielding were prepared by incorporating liquid metals (LMs). The composites exhibited high absorption loss and low reflection loss, effectively reducing secondary microwave pollution. The microwave shielding performance of the composites containing LMs could be regulated by compression.