Nacre-like robust cellulose nanofibers/MXene films with high thermal conductivity and improved electrical insulation by nanodiamond

The development of materials with efficient heat dissipation capabilities and remarkable mechanical properties is essential for high-power integrated electronic devices and flexible smart devices. Herein, a flexible cellulose nanofibers (CNF)/nanodiamond (ND)/MXene (CNM) composite film with typical nacre-like structure is fabricated using a facile vacuum-assisted filtration approach. The composite film exhibits high thermal conductivity of 17.43 W m −1  K −1 at the thickness of 21 μm, which enhances 663% compared with CNF film. This is mainly due to the bridging effect of ND and the favorable orientation of MXene nanosheets. In addition, nacre-like structure and strong hydrogen bonding between MXene and CNF endow satisfactory mechanical properties (89.14 ± 3.61 MPa). Moreover, it is worth to note that the film exhibits improved electrical insulation (1.63 × 10 6 Ω cm) on account of the intervene of the insulating ND block the conductive path formed by MXene. Therefore, the CNM composite films provide a feasible choice of thermal management components for high-power flexible devices.