Interfacial design of nanocellulose/boron nitride nanosheets composites via calcium ion cross-linking for enhanced thermal conductivity and mechanical robustness

Highly thermally conductive composites with synergetic mechanical robustness and desirable thermal stability are crucially significant for the effective thermal management of modern electronics, yet it remains challenging due to the unsatisfied interfacial interactions. Herein, high aspect ratio carboxylated carbon nanotubes (c-CNTs) and calcium ion cross-linking strategy were innovatively introduced in cellulose nanofibers (CNFs)/boron nitride nanosheets (BNNS) composites to achieve their interfacial regulation and multifunctional integration. Impressively, the resultant Ca 2+ -CNFs/BNNS/c-CNTs composites exhibited a densely packed hierarchical structure and strong interfacial interactions, which provided continuous thermal conduction path for phonons transport. As a result, the Ca 2+ -CNFs/BNNS/c-CNTs composites were endowed with high in-plane thermal conductivity (13.46 W m −1 K −1 ), promising tensile strength (134 MPa), and excellent thermal stability. These findings provide a feasible interfacial engineering strategy to design the high-performance thermally conductive composites, holding great promise for advanced thermal management applications in modern electronics.