We develop a general approach to the fabrication of films with unidirectional grooves,such as silicon nitride, silicon dioxide and aluminium oxide,in which the surface is not required to be treated.Super-aligned carbon nanotube (SACNT) film may be used as a template and as sacrificial layer,which is subsequently removed by heating in an atmosphere of air.The unidirectional morphology of the SACNT film turns into a desired film,which is found to possess the ability to align liquid crystal molecules.This approach also features high efficiency,low cost and easy scaling-up for mass production.
