A Shifted Double-Diamond Titania Scaffold

Photonic crystals are expected to be metamaterials because of their potential to control the propagation of light in the linear and nonlinear regimes. Biological single-network, triply periodic constant mean curvature surface structures are considered excellent candidates owing to their large complete band gap. However, the chemical construction of these relevant structures is rare and developing new structures from thermodynamically stable double-network self-organizing systems is challenging. Herein, we reveal that the shifted double-diamond titania scaffold can achieve a complete band gap. The largest (7.71%) band gap is theoretically obtained by shifting 0.332c with the dielectric contrast of titania (6.25). A titania scaffold with similar shifted double-diamond structure was fabricated using a reverse core-shell microphase-templating system with an amphiphilic diblock copolymer and a titania source in a mixture of tetrahydrofuran and water, which could result in a 2.05-3.78% gap.