Facile preparation of thermally conductive fiber film by self-assembling interconnected boron nitride nanosheets for effective thermal interface materials

Boron nitride (BN) has garnered significant attention for its potential in developing thermally conductive materials owing to its inherent insulating properties and high thermal conductivity. However, achieving high thermal conductivity in bulk materials or 3D structures constructed by BN sheets has remained challenging. In this study, we present a novel approach to design a high-quality BN fiber using xanthan gum (XG) as a skeleton, aiming to facilitate heat dissipation in integrated circuits. The resulting thermally conductive film, with orderly and compactly arranged BN sheets in the XG skeleton, exhibits a remarkable in-plane thermal conductivity of 8.26 Wm⁻¹ K⁻¹ and an out-of-plane thermal conductivity of 1.35 Wm⁻¹ K⁻¹. This film efficiently enables fast heat dissipation for LED chips and thermoelectric generators. Finite element simulation further supports the efficient heat transfer capacity of the BN fiber films. Highlights: A high-quality BN fiber was prepared by a facile approach. The BN fiber film exhibited high thermal conductivity. This film enables fast heat dissipation in practical applications.