Simultaneously enhanced in-plane and through-plane thermal conductivity of the bacterial cellulose composite prepared via a facile method

The concurrent improvement of in-plane and through-plane thermal conductivity in composite films is of significant interest in the field of thermal interface materials (TIMs) for achieving efficient heat dissipation in electronic devices. Nevertheless, the majority of composite materials fabricated to date generally fail to exhibit high thermal conductivity in both vertical and horizontal directions. Herein, Si/GNPs/BC (bacterial cellulose) composite films with a sandwich-like structure have been prepared via a facile vacuum-assisted filtration (VAF) method. Zero-dimensional (0D) silicon (Si) particles dispersed between two-dimensional (2D) graphene nano- platelets (GNPs) establish thermal conductive pathways in the vertical direction, whereas the lateral arrangement of GNPs forms thermal conductive pathways in the horizontal direction. This configuration results in in- plane and through-plane thermal conductivities reaching 5.389 W/m center dot K and 1.794 W/m center dot K, respectively, representing a 3-fold and 10-fold enhancement over those of pure BC, respectively. In addition, the tensile strength of the 50Si/50GNPs/BC composite film is 13.5 MPa, which presents a 41 % increase over the pure BC film. Moreover, the flame retardancy and thermal stability of the composite films have also been improved, which could expand the application of Si/GNPs/BC composite films. Thus, the preparation of Si/GNPs/BC composite films provides a novel strategy for the development of high-performance thermal management materials.