(317e) Template-Mediated Control of Hierarchical Structure in Crystalline and Amorphous Porous Materials

This talk will describe physicochemical insights into a templating strategy aimed at the synthesis of hierarchically structured, high-surface area, large-pore volume three-dimensionally ordered mesoporous (3DOm) materials. The accessible materials palette, spanning carbons to various metal oxides (e.g., TiO₂, ZrO₂), enables scalable synthesis of structured particles tailored for applications ranging among separations, photocatalytic decomposition of bulky molecules, and even enhanced supercapacitor and solar cell electrode technologies. The templating strategy employs synthetic size-tunable silica nanoparticles (ca. 5-50 nm) and their uni- and multi-modal colloidal crystalline assemblies for hard, sacrificial nanocasting of 3DOm replica structures. Ultimately, this approach enables multi-scale tailoring of replica properties. Specifically, at the mesoscale, topological diversity and 3D hierarchy of the templated pores can be controlled by exploiting multi-modal particulate porogen assembly or by â??one-potâ?? co-assembly techniques (i.e., molecular replica precursors with particulate porogens). Emerging from the latter approach is a new class of materials with independent and interdigitated bimodal mesoporosity. Simultaneously, at the microscale, template-mediated interfacial control of replica polymorphism, allotropy, and even molecular scale function can also be achieved. This control across scales translates to enhanced molecular accessibility/transport and tailored function (e.g., catalytic, adsorptive, size selectivity) of the porous replica materials.