In-situ constructing efficient three-dimensional thermal network in MXene@TA-Ag/BC (MTAB) composite films via vacuum-assisted self assembly: Role of heterointerface optimization

Addressing the demand for high-thermal-conductivity composites in flexible electronics thermal management, this study designed a bioinspired composite film based on bacterial cellulose (BC) nanofibers as the flexible matrix. The MXene@TA-Ag/BC (MTAB) composite film with a “brick-and-mortar” biomimetic structure was constructed through vacuum-assisted filtration and hot-pressing processes, incorporating tannic acid (TA)-modified MXene nanosheets with in situ loaded silver nanoparticles (AgNPs). The dihydroxy groups of TA not only facilitated the uniform deposition of AgNPs on MXene surfaces but also formed multiple hydrogen bonds with the BC matrix, significantly enhancing interfacial compatibility. When the mass fraction of the composite filler reached 40 %, the in-plane thermal conductivity of the as-prepared composite films significantly increased from 2.66 W/m·K (of pure BC films) to 10.99 W/m·K, representing an increase of 313.8 % in comparison to that of pure BC matrix. Mechanical characterization further revealed remarkable tensile strength (114.8 MPa), primarily attributed to synergistic stress-transfer between MXene@TA-Ag fillers and the BC matrix. Thermogravimetric analysis demonstrated superior thermal stability with a maximum decomposition temperature of 277.4 °C, indicating suitability for high-temperature applications.The present work achieved synergistic optimization of thermal and mechanical properties through a multi-scale interfacial engineering strategy, offering new insights for developing next-generation flexible thermal interface materials.