Highly ordered arrays of mesoporous silica nanorods with tunable aspect ratios from block copolymer thin films

A study has reported the preparation of a highly ordered array of mesoporous silica (SiO₂) nanorods with tunable aspect ratios, through an integrated strategy of block copolymer lithography and evaporation-induced self-assembly method (EISA). The diameter and the center-to-center distance of the SiO₂ nanorods can be tuned by selecting suitable block copolymer thin films while the height of the SiO₂ nanorods can be controlled by variation of immersion time and thickness of the block copolymer thin films. The study showed that nanorods of nearly 200 nm height were achieved, with an aspect ratio of 15, while mesochannels with a diameter of 2 nm were formed inside and aligned along the longitudinal axis of the SiO₂ nanorods. The study also showed that highly ordered tunable SiO₂ nanorod arrays have a tremendous potential for sensory, on-chip separation, and optoelectronic applications.