[Nano Research]Multifunctional Ti3C2Tx-(Fe3O4/polyimide) composite films with Janus structure for outstanding electromagnetic interference shielding and superior visual thermal management
writer：Yali Zhang, Zhonglei Ma, Kunpeng Ruan and Junwei Gu*
keywords：Electromagnetic interference shielding，MXene，MXene/polymer composites，Research progress
source：期刊
specific source：Nano Research
Issue time：2022年
Flexible multifunctional polymer-based electromagnetic interference (EMI) shielding composite films have important application values in the fields of 5G communication technology, wearable electronic devices and artificial intelligence. In this work, Fe3O4/polyamic acid (PAA) nanofiber films are prepared by in-situ polymerization and electrospinning technology, and Ti3C2Tx nanosheets are deposited on the surface of the Fe3O4/PAA nanofiber films via vacuum-assisted filtration. Then, Janus Ti3C2Tx-(Fe3O4/polyimide (PI)) composite films are obtained by thermal imidization. The two sides of the Janus films exhibit completely different properties. The Fe3O4/PI side has excellent hydrophobicity and insulation property, and the Ti3C2Tx side has terrific hydrophilicity and conductivity. When the mass fraction of Ti3C2Tx is 80 wt%, the Janus Ti3C2Tx-(Fe3O4/PI) composite film has excellent EMI shielding performances and mechanical properties, with EMI shielding effectiveness, tensile strength and Young’s modulus reaching 66 dB, 114.5 MPa and 5.8 GPa, respectively. At the same time, electromagnetic waves show different absorption shielding effectiveness (SEA) when incident from two sides of the Janus films. When the electromagnetic waves are incident from the Fe3O4/PI side, the SEA of the Janus film is 58 dB, much higher than that when the electromagnetic waves are incident from the Ti3C2Tx side (39 dB). In addition, the Ti3C2Tx side of the Janus Ti3C2Tx-(Fe3O4/PI) composite films also have excellent electrothermal and photothermal conversion performances. When the applied voltage is 4 V, the stable surface temperature reaches 108oC; when it is irradiated by simulated sunlight with power density of 200 mW/cm2, the stable surface temperature reaches 95oC.
柔性多功能聚合物基電磁干擾（EMI）屏蔽復合膜在5G通信技術、可穿戴電子設備和人工智能等領域具有重要的應用價值。本文通過“原位聚合-靜電紡絲”法制備四氧化三鐵/聚酰胺酸（Fe3O4/PAA）納米纖維膜，借助真空輔助抽濾在Fe3O4/PAA納米纖維膜表面沉積Ti3C2Tx納米片，再經熱亞胺化制備具有Janus結構的Ti3C2Tx-（Fe3O4/聚酰亞胺（PI））復合膜。該復合膜兩側表現出截然不同的性質，Fe3O4/PI側具有優異的疏水性和絕緣性，而Ti3C2Tx側具有出色的親水性和導電性。當Ti3C2Tx質量分數為80 wt%時，Ti3C2Tx-（Fe3O4/PI）復合膜兼具優異的屏蔽性能和力學性能，EMI屏蔽效能達到66 dB、拉伸強度和楊氏模量分別達到114.5 MPa和5.8 GPa。同時，電磁波從Janus結構復合膜兩側入射時表現出不同的EMI吸收屏蔽效能（SEA）。當電磁波從Fe3O4/PI側入射時，復合膜的SEA為58 dB，遠高于從Ti3C2Tx側入射時的SEA（39 dB）。此外，Ti3C2Tx-（Fe3O4/PI）復合膜的Ti3C2Tx側還具有優異的電熱和光熱轉化性能。當施加4 V電壓時，其表面穩定溫度達到108oC；當受到功率密度為200 mW/cm2模擬太陽光照射時，表面穩定溫度達到95oC。