Hydrothermal synthesis of boehmite nanorods from alumina sols

Boehmite nanorods (BNRs) were synthesized via the sol-gel process and hydrothermal method from alumina sols. Four influence factors, i.e. hydrothermal temperature and time, acetic acid contents, alcohol contents and stirring patterns, were explored to understand the reasons of BNRs growth. Scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared (FT-IR) spectra and X-ray diffraction (XRD) were used to investigate the micromorphology, functional groups and phase composites of BNRs. The results show that the hydrothermal temperature and the contents of acetic acid play important parts in the one-dimension (1D) growth of BNRs. However, the hydrothermal time and the contents of alcohol have little effects. The growth mechanism of BNRs is related to the formation, growth and directional assembling of boehmite crystallites. After the simulation of dissipative particle dynamics (DPD), the increase of shear rate is beneficial to the 1D growth of BNRs.