A waste hemp-based biomass carbon aerogel with high fire-resistance

To enhance the efficient utilization of waste hemp rods, a kind of three-dimensional (3D), mesh-like lamellar structured hemp-based biomass carbon aerogel (CA) was developed by freeze-drying and subsequent high-temperature carbonization method. The microstructure, flame resistance, thermal stability, and thermal conductivity of CA were investigated using several analytical techniques, including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), simulated combustion tests, and thermogravimetric analysis (TG). Optimum formulation yielded at an alkali treatment concentration of 20% and a carbonization temperature of 700°C, CA with a 3D network of reticulated lamellae was obtained. CA exhibited minimal values for thermal conductivity (0.06 W/m K) and thermal diffusion coefficient (0.41 mm 2 /s), which are indicative of superior insulative properties. Moreover, the material demonstrated remarkable thermal endurance and flame resistance, achieving a char yield of 70.03% when subjected to a temperature of 700°C in an oxidative environment.