From nanotubes to nano-cocoons with coiled pore channels

Silica nanotubes with coiled pore channels and hollow spheres with coiled or concentric circular pore channels have been prepared using the self-assemblies of chiral cationic amphiphiles as templates. However, the relationship among these morphologies and pore architectures has not been well studied. For a better understanding the relationship, silica nanostructures were systematically prepared by tuning the reaction conditions. With increasing the stirring rate, silica nanotube with coiled pore channels changed to linked nano-cocoon with coiled pore channels. With increasing the concentration of the reaction mixture, the morphology changed from sphere to linked cocoon, and then to nanorod with lamellar mesopores on the surface. Transmission electron microscopy images taken after different reaction times indicated a cooperation mechanism.