3D Shapeable, Superior Electrically Conductive Cellulose Nanofibers/Ti3C2Tx MXene Aerogels/Epoxy Nanocomposites for Promising EMI Shielding

Lei Wang; Ping Song; Cheng-Te Lin; Jie Kong; Junwei Gu

doi:10.34133/2020/4093732

3D Shapeable, Superior Electrically Conductive Cellulose Nanofibers/Ti₃C₂T_x MXene Aerogels/Epoxy Nanocomposites for Promising EMI Shielding

Research (Wash D C). 2020 Jun 17:2020:4093732. doi: 10.34133/2020/4093732. eCollection 2020.

Authors

Lei Wang¹, Ping Song¹, Cheng-Te Lin², Jie Kong¹, Junwei Gu¹

Affiliations

¹ Shaanxi Key Laboratory of Macromolecular Science and Technology, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China.
² Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, Ningbo 315201, China.

Abstract

In this work, 3D highly electrically conductive cellulose nanofibers (CNF)/Ti₃C₂T_x 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 thermal 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% Ti₃C₂T_x. When the volume fraction of Ti₃C₂T_x 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 filler content. In addition, compared to those of the samples without Ti₃C₂T_x, the storage modulus and heat-resistance index of TCTA/epoxy nanocomposites are enhanced to 9792.5 MPa and 310.7°C, increased by 62% and 6.9°C, 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.