Preparation of Multilayered Trimodal Colloid Crystals and Binary Inverse Opals

Abstract

We report for the first time the preparation of multilayered trimodal colloid crystals (tCC) and their corresponding binary inverse opals (bIO), which present complex hierarchical structures that may have significant potential in photonics, phononics, separations, and catalysis, among others. A trimodal colloidal mixture of 465 nm polystyrene (PS), 84 nm poly(methyl methacrylate) (PMMA), and 6 nm silica particles in suspension was transferred onto a glass substrate and self-assembled into highly ordered trimodal crystal structures during vertical lifting deposition. Pyrolysis of the organic particles in the tCC resulted in silica bIO with interconnected meso- and macropores. Vis-NIR spectra of all structures were analyzed to reveal the internal architecture with each PS sphere correlating to 21-23 PMMA particles (a LI21-23 stoichiometry), which corresponded well with computer models.