Tailoring the thermal transport properties of cellulose and lignin laser-induced graphene

Graphene ' s incredibly high thermal conductivity makes it a desirable material for heat dissipation and thermal management. A simple method of manufacturing graphene is the direct laser writing of rich carbon polymeric substrates, called laser-induced graphene (LIG); this is helpful in various applications, including sensors, catalysts, and supercapacitors. In this study, the thermal conductivity of cellulose and lignin-derived LIG (C-LIG and L-LIG) was investigated using the non-equilibrium molecular dynamics (NEMD) approach at various temperatures, lengths, and interatomic potentials, Airebo and opt-tersoff. This paper is the first study to investigate and calculate the thermal properties of laser-induced graphene, such as thermal conductivity coefficient and VDOS computations, using a molecular dynamics approach under various influential conditions (temperature, length, and interatomic potential). It particularly focuses on using biopolymers like lignin and cellulose to produce LIG. This study offers new and comprehensive insights into this type of graphene and the potential of these natural substrates for LIG production. The findings of this research were compared with those of defective and bi-layer graphene due to LIG ' s bi-layer structure and various defects. The AIREBO potential leads to a much lower estimation of thermal conductivity than the Tersoff parameters themselves. This is due to neglecting out-of-plane scattering and the low velocities of transverse and longitudinal acoustic branches in the AIREBO potential. Finally, C-LIG has a higher thermal conductivity than L-LIG due to the fewer defects in C-LIG than L-LIG; however, using Opt-Tersoff potential led to a 20% decrease in thermal conductivity. The thermal conductivity coefficient of layered graphene falls as the number of layers rises due to long phonon paths, large grain size, and a regular structure. The VDOS result shows graphene ' s prominent G-peak at approximately 50 THz.