A novel sol–gel synthetic route to alumina nanofibers via aluminum nitrate and hexamethylenetetramine

Attempts have been made to prepare alumina nanofibers by hydrolyzing aluminum nitrate in the presence of hexamethylenetetramine (HMTA) followed by the supercritical fluid drying (SCFD) process. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen physisorption. The results show that δ-Al2O3 nanofibers with diameter of 2 nm, length of 50 nm and with BET surface areas of 412.6 m2 g− 1 were successfully synthesized. The thermal evolution of the fibers and the role of hexamethylenetetramine were also briefly discussed.