Lei Wang, Ping Song, Cheng-Te Lin, Jie Kong and Junwei Gu*. 3D Shapeable, Superior Electrically Conductive Cellulose Nanofibers/Ti3C2Tx MXene Aerogels/Epoxy Nanocomposites for Promising EMI Shielding. Research, 2020, 2020: 4093732.
https://doi.org/10.34133/2020/4093732
Abstract: In this work, 3D highly electrically conductive cellulose nanofibers (CNF)/Ti3C2Tx MXene aerogels (CTA) with aligned porous structures are fabricated by directional freezing followed by freeze-drying technique, and the thermally annealed CTA (TCTA)/epoxy nanocomposites are then fabricated by thermally annealing of CTA, subsequent vacuum-assisted impregnation and curing method. Results show that TCTA/epoxy nanocomposites possess 3D highly conductive networks with ultralow percolation threshold of 0.20 vol% Ti3C2Tx. When the volume fraction of Ti3C2Tx is 1.38 vol%, the electrical conductivity (σ), electromagnetic interference shielding effectiveness (EMI SE), and SE divided by thickness (SE/d) values of the TCTA/epoxy nanocomposites reach 1672 S m-1, 74 dB, and 37 dB mm-1, respectively, which are almost the highest values compared to those of polymer nanocomposites reported previously at the same fillers content. In addition, compared to those of the samples without Ti3C2Tx, the storage modulus and heat-resistance index of TCTA/epoxy nanocomposites are enhanced to 9792.5 MPa and 310.7oC, increased by 62% and 6.9oC, respectively, presenting outstanding mechanical properties and thermal stabilities. The fabricated lightweight, easy-to-process, and shapeable TCTA/epoxy nanocomposites with superior EMI SE values, excellent mechanical properties, and thermal stabilities greatly broaden the applications of MXene-based polymer composites in the field of EMI shielding.本工作基于定向冷凍-冷凍干燥法制備3D各向異性高導電纖維素納米纖維/Ti3C2Tx氣凝膠（CTA），再經熱還原-真空輔助浸漬法制備熱還原Ti3C2Tx氣凝膠（TCTA）/環氧樹脂納米復合材料。結果表明，TCTA/環氧樹脂納米復合材料具有完整、高效的3D導電網絡和極低的滲濾閾值（0.20 vol% Ti3C2Tx）。當TCTA體積分數為1.38 vol%時，TCTA/環氧樹脂納米復合材料的徑向電導率（σ）、軸向EMI SE和單位厚度屏蔽效能（SE/d）分別高達1672 S m-1、74 dB和37 dB mm-1，均幾乎優于以往報道的聚合物基導電復合材料。此時，TCTA/環氧樹脂納米復合材料還具有優異的力學性能和熱穩定性，其儲能模量和耐熱指數（THRI）分別為9792.5 MPa和310.7oC，較熱還原纖維素納米纖維/環氧樹脂納米復合材料分別提高了62%和6.9oC。這種輕質、簡單易得、可塑性強的高導電、高屏蔽效能、優異力學性能和出眾熱穩定性的TCTA/環氧樹脂納米復合材料的制備及批量化生產將大大拓寬MXene納米材料在EMI領域中更廣的應用。
附第一作者（王雷）個人簡介：。
王雷，男，陜西商洛人，2018級博士研究生。2016年在西北工業大學獲學士學位，2016年免試攻讀碩士學位并于2018年碩博連讀。主要從事3D MXene泡沫、氣凝膠結構及其環氧樹脂基電磁屏蔽復合材料的制備及機理研究。參與航天科學技術基金2項和校研究生種子基金2項。2018~2019學年博士研究生國家獎學金獲得者。在Research、Carbon、Composites Part B: Engineering和Journal of Materials Science & Technology等期刊發表SCI論文16篇，其中第一作者（含導師第一）SCI論文6篇。SCI引用650余次（入選第一作者ESI熱點論文2篇、高被引論文2篇），H因子11；參加國際會議3次并作口頭報告；授權、公開國家發明專利8件。