Controlling optical properties of disordered materials like gels is challenging because their structure is heterogeneous and strategies for tuning are few

• Consistent and tunable structure ITO nanocrystal gel networks was achieved with thermoreversible metal coordination links
• Small angle X-ray scattering was used to quantify changes in inter-nanocrystal spacing as the ligand length was synthetically varied
• A “plasmon ruler” that was developed and theoretically verified that can predict the plasmonic optical frequency of a gel

The plasmon ruler enables design of dynamic optical response by selection of nanocrystals and ligands

• Design of mixtures with optical spectra that either broaden or counterintuitively narrow upon gel formation was demonstrated
• Future development of the computational design principles and dynamic linking chemistries will be used to encode time-dependent responsive optical properties in nanocrystal assemblies