Enhanced heat transfer of nanocellulose–graphene membrane: experiment and molecular dynamics simulation study

Nanocellulose (NC) as a stable carrier and matrix with high mechanical strength, low thermal expansion, and high electrical resistivity is full of potential to be used in green electronics, energy storage device, and sensors. In this study, a nanocellulose/graphene (NC/G) membrane is designed and successfully prepared in order to modify thermal transport of NC. The experimental results indicate that the NC/G membrane possesses strong interfacial interactions and highly ordered structures, and the heat transfer ability of the composite membrane is enhanced due to the addition of graphene. Molecular dynamics simulations are also used to predict the role of the temperature, covalent bonding and strains on the thermal conductivity of NC/G membrane. The in-plane and cross-plane thermal conductivities of the NC/G membrane can reach to 8.804 W/(m K) and 1.132 W/(m K), respectively, which show obvious characteristics of anisotropy. The the phonon density of states (PDOS) is calculated to further reveal the phonon transport mechanism of NC/G membranes. The results from this study will provide some effective guidence to impove the thermal conductivity of the hybrid organic–inorganic nanocomposites.