Nanostructure Dependent Surface Energy of Silica Nanorod Arrays through Block Copolymer Templating Processes

摘要

The self-assembled block copolymer films with poly(ethylene oxide) (PEO) and hydrophobic polymetharylate (PMA) with azobenzene mesogen in the side chain, denoted as PEO_m-b-PMA(Az)_n, were used as the template to prepare hexagonally ordered silica nanorod arrays by immersing the template films in the silicate precursor containing tetraetoxysilane (TEOS). The diameter and the center-to-center distance of the SiO_2 nanorod arrays were controlled by selecting the block copolymer with different PEO volume fraction. In addition, the contact angles of different kinds' solvents for the SiO_2 nanorod arrays were characterized. We further found, the diameter and the period distance of silica nanorods are very important factors for controlling the contact angle of different kind's solvents on the surface of the SiO_2 nanorod arrays.