Large-scale synthesis of Al4B2O9/Al18B4O33 whiskers via a novel method

The Al4B2O9/Al18B4O33 whiskers were synthesized by a facile route based on the calcination of amorphous aluminum borate, which are prepared by the homogeneous precipitation reaction between aluminum isopropoxide and H3BO3 isopropyl alcohol solution. The structure and morphology were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicate that both whiskers with the identical morphology exhibit a well-crystallized structure with an average diameter distribution about 400 nm and lengths ranging from 3 to 5 μm. The growing process of Al4B2O9/Al18B4O33 whiskers has been studied by thermo-gravimetric and simultaneous differential thermal analysis (TG/DTA).