Journal ArticleGelation of plasmonic metal oxide nanocrystals by polymer-induced depletion attractionsSaez Cabezas, Camila A.; Ong, Gary K.; Jadrich, Ryan B.; Lindquist, Beth A.; Agrawal, Ankit; Truskett, Thomas M.; Milliron, Delia J.<title>Significance</title> <p>Self-supported gelation of optically active nanocrystals offers a modular pathway to harness optoelectronic functionality in multiscale materials by directly controlling volume fraction, bonding, and structure during assembly. We combine depletion attractions that emerge from the incorporation of small polymer chains and electrostatic repulsions to induce the gelation of isotropic metal oxide nanocrystals. We develop a theoretical model to assess our experimental fluid-to-gel-phase progression observations. By preventing nanocrystal fusion during network assembly, we achieve gels with a strong near-infrared absorption, reminiscent of the inherent near-infrared localized surface plasmon resonance of the nanocrystal building blocks.</p>Proceedings of the National Academy of Sciences2018-09-0410476187Proceedings of the National Academy of Sciences115368925 to 89300027-8424https://doi.org/10.1073/pnas.18069271151720595National Science Foundation