Closed and Open Architecture Colloidal Crystals with Properties by Design

The ultimate vision for the field of functional materials by design is to identify a desired function or set of materials properties, apply rigorous design rules to define the structure and chemistry, and then synthesize and characterize that material with absolute positional and compositional control. The collaborative efforts of the Mirkin, Dravid, and Aydin groups have pioneered DNA as the ultimate, programmable nanoscale interaction to build nanoparticle-based materials from the bottom-up. However, building a material with specific functions by design remains challenging. Here, we propose to address this challenge by expanding the architectural complexity and diversity accessible through colloidal crystal engineering and exploring the properties of nanoparticle superlattices across a range of optical, catalytic, and mechanical functions. These novel materials will exhibit unrivalled structural sophistication—inaccessible through any other means—that will result in new and unusual materials properties including negative refractive indices, synergistic catalytic behavior, and auxetic mechanical actuation. We have assembled a multidisciplinary team at Northwestern University that includes experts in nanomaterial synthesis, assembly, structural and properties characterization, and simulations and modeling. The proposed scheme of work will not only generate new materials with functions of substantial importance to improving the performance, durability, and technical capabilities of the U.S. Air Force and Space Force but will also contribute to fundamental scientific knowledge and the training of new scientific talent.