Thermal study of boehmite nanofibers with controlled particle size

Boehmite nanofiber materials with controlled particle size were synthesized without any surfactant by careful tuning of the hydrothermal temperatures, and followed by a series of characterizations. It was found that the boehmite nanofibers became shorter and coarser with the increase of temperature, and resulted in a gradual decrease of their specific surface areas. Moreover, the thermal stability of the boehmite nanofibers was studied by in situ HT X-ray diffraction and thermogravimetry-differential scanning calorimetry. All materials showed the phase transition from gamma-Al2O3 to other forms. Yet the transition temperature was increased with the increase of hydrothermal temperature. The boehmite nanofibers with the largest diameter showed the best thermal stability.