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

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 [PEO_m-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.