[Research]3D Shapeable, Superior Electrically Conductive Cellulose Nanofibers/Ti3C2Tx MXene Aerogels/Epoxy Nanocomposites for Promising EMI Shielding
作者：Lei Wang, Ping Song, Cheng-Te Lin, Jie Kong and Junwei Gu*
關(guān)鍵字：Electrically Conductive ,Cellulose Nanofibers, MXene Aerogels
論文來(lái)源：期刊
具體來(lái)源：Research
發(fā)表時(shí)間：2020年
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(dǎo)電纖維素納米纖維/Ti3C2Tx氣凝膠（CTA），再經(jīng)熱還原-真空輔助浸漬法制備熱還原Ti3C2Tx氣凝膠（TCTA）/環(huán)氧樹(shù)脂納米復(fù)合材料。結(jié)果表明，TCTA/環(huán)氧樹(shù)脂納米復(fù)合材料具有完整、高效的3D導(dǎo)電網(wǎng)絡(luò)和極低的滲濾閾值（0.20 vol% Ti3C2Tx）。當(dāng)TCTA體積分?jǐn)?shù)為1.38 vol%時(shí)，TCTA/環(huán)氧樹(shù)脂納米復(fù)合材料的徑向電導(dǎo)率（σ）、軸向EMI SE和單位厚度屏蔽效能（SE/d）分別高達(dá)1672 S m-1、74 dB和37 dB mm-1，均幾乎優(yōu)于以往報(bào)道的聚合物基導(dǎo)電復(fù)合材料。此時(shí)，TCTA/環(huán)氧樹(shù)脂納米復(fù)合材料還具有優(yōu)異的力學(xué)性能和熱穩(wěn)定性，其儲(chǔ)能模量和耐熱指數(shù)（THRI）分別為9792.5 MPa和310.7oC，較熱還原纖維素納米纖維/環(huán)氧樹(shù)脂納米復(fù)合材料分別提高了62%和6.9oC。這種輕質(zhì)、簡(jiǎn)單易得、可塑性強(qiáng)的高導(dǎo)電、高屏蔽效能、優(yōu)異力學(xué)性能和出眾熱穩(wěn)定性的TCTA/環(huán)氧樹(shù)脂納米復(fù)合材料的制備及批量化生產(chǎn)將大大拓寬MXene納米材料在EMI領(lǐng)域中更廣的應(yīng)用。