在含液态金属的多壁碳纳米管/聚二甲基硅氧烷复合材料中实现高性能、可调谐的微波屏蔽

In this study, multi-walled carbon nanotube-filled polydimethylsiloxane (CNT/PDMS) composites with high-performance 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 high-performance 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.