Chaobo Liang, Jie He, Yali Zhang, Wei Zhang, Chunlei Liu, Xiangteng Ma, Yaqing Liu* and Junwei Gu*. MOF-derived CoNi@C-silver nanowires/cellulose nanofiber composite papers with excellent thermal management capability for outstanding electromagnetic interference shielding. Composites Science and Technology, 2022, 224: 109445. 2021IF=9.879.（1區材料科學Top期刊）
https://doi.org/10.1016/j.compscitech.2022.109445
Abstract
High-performance electromagnetic interference (EMI) shielding materials with excellent flexibility and superior thermal management properties are ideal candidates for aerospace, communication industry, artificial intelligence, and wearable electronics. Herein, MOF-derived CoNi@C-silver nanowires/cellulose nanofiber (MAg/CNF) composite papers with Janus structure were prepared using a combination of two-step vacuum filtration and hot pressing. The resulting composite papers exhibit distinct electrical differences on both sides. The electrical conductivity of the CoNi@C/CNF side is 8.35×10-12 S/cm, while that of the AgNWs/CNF side is 990 S/cm. EMI shielding effectiveness (SE) of the MAg/CNF composite papers reaches 82 dB in the X-band, benefiting from effective double-layer structure, the AgNWs conductive network and the CoNi@C permeability network for adequate dissipation of electromagnetic waves. Excellent EMI shielding performance is maintained even after being subjected to low temperature of -196℃ and bending cycles of 1000 times. In addition, the MAg/CNF composite paper-based electric heaters exhibit satisfactory heating temperatures at absolutely safe operating voltages for the human as well as sufficient stability and repeatability during repeated heating and cooling cycles. Therefore, our fabricated MAg/CNF composite papers with Janus structure present broad application prospects for high-performance EMI shielding and thermal management in low-temperature environment.
具有出色的柔韌性、卓越的熱管理性能的高性能電磁干擾（EMI）屏蔽材料是航空航天、通訊工業、人工智能、可穿戴電子等領域的理想候選。在這項工作中，具有雙面結構的CoNi@C-AgNWs/cellulosic nanofiber（MAg/CNF）復合紙被制備采用兩步真空抽濾自組裝和熱壓相結合的方法。所得的雙層復合紙展現出“一面絕緣、一面導電”特性，CoNi@C/CNF面的電導率低至8.35×10-12 S/cm，而AgNWs/CNF面的電導率高至990 S/cm。MAg/CNF復合紙的EMI屏蔽效能（EMI SE）達到82 dB在X波段，得益于有效的雙層結構、AgNWs導電網絡和CoNi@C導磁網絡對電磁波的充分耗散。即使在經受-196℃的低溫和1000次彎曲循環后，復合紙仍可保持卓越的EMI屏蔽性能。此外，MAg/CNF復合紙基電加熱器在人體絕對安全的工作電壓下表現出令人滿意的加熱溫度以及在長期和重復的加熱和冷卻循環中具有足夠的穩定性和可重復性。因此，具有雙面結構的復合紙在低溫環境下高性能EMI屏蔽和熱管理應用方面具有廣闊的應用前景。
本文亮點
1. MAg/CNF復合紙在X波段的EMI SE達到82 dB，并且具有優良的低溫和機械穩定性。
2． Janus結構賦予MAg/CNF復合紙一面絕緣（8.35×10-12 S/cm），一面導電（990 S/cm）的獨特性質。
3． MAg/CNF復合紙表現出優異的熱管理性能，其可以與硅膠墊集成制備具有良好親膚效果和熱療功能的可穿戴護腕。
第一作者郵箱：lcb@mail.nwpu.edu.cn