Hexagonally Arrayed 17 nm Interpenetrating and Continuous Biphasic Structure via Block-Copolymer-Templating Process

Abstract

Biphasic and interpenetrating continuous membranes with precisely controlled two-dimensional (2D)-hexagonal nanoperiodicity were fabricated using amphiphilic block copolymer poly(ethylene oxide)-b-polymethacrylate with azobenzene mesogen units in the side chain [PEOm-b-PMA(Az)n]. On a silica (SiO2) nanodot array templated from the block copolymer membrane, the next phase, such as titanium dioxide (TiO2), or gold (Au), was coated. Herein, the surface modification of the transferred SiO2 nanodot array was crucial to obtaining the interpenetration of the precursor of TiO2 and its continuous contact. The typical size of the hexagonal array (d) and the center-to-center distance (D) of the SiO2 nanodots were (d, D) = (17 nm, 27 nm) and (d, D) = (22 nm, 51 nm), respectively. The interpenetrating and continuous biphasic structure will provide a promising approach to multiferroic materials, interpenetrative heterojunction for solar cells, new integrated catalysts, and so forth.