The influence of hydrothermal-reaction parameters on the formation of chrysotile nanotubes

X-ray diffraction and transmission electron microscopy were used to investigate the hydrothermal formation of chrysotile Mg3[Si2O5](OH)4 nanotubes from amorphous SiO2 and nanocrystalline Mg(OH)2. The results show that nanotubes form readily in a highly basic hydrothermal environment via the curling of flake-like nanocrystallites with a serpentine-type Mg–Si bilayer crystal structure. The curling occurs in a helical manner, which introduces chirality into the structure of the resulting tubes. The diameter and length of the nanotubes can be controlled by varying the temperature and time of the hydrothermal reaction.