Colorimetric quantification of linking in thermoreversible nanocrystal gel assemblies
|Valenzuela, Stephanie A.
|Lin, Emily Y.
|Dominguez, Manuel N.
|Sherman, Zachary M.
|Truskett, Thomas M.
|Anslyn, Eric V.
|Milliron, Delia J.
|Nanocrystal gels can be responsive, tunable materials, but designing their structure and properties is challenging. By using reversibly bonded molecular linkers, gelation can be realized under conditions predicted by thermody- namics. However, simulations have offered the only microscopic insights, with no experimental means to monitor linking leading to gelation. We introduce a metal coordination linkage with a distinct optical signature allowing us to quantify linking in situ and establish structural and thermodynamic bases for assembly. Because of coupling between linked indium tin oxide nanocrystals, their infrared absorption shifts abruptly at a chemically tunable gelation temperature. We quantify bonding spectroscopically and use molecular simulation to understand temperature-dependent bonding motifs, revealing that gel formation is governed by reaching a critical number of effective links that extend the nanocrystal network. Microscopic insights from our colorimetric linking chemistry enable switchable gels based on thermodynamic principles, opening the door to rational design of programmable nanocrystal networks.
|Center for Dynamics and Control of Materials
|We would like to thank the University of Texas at Austin Mass Spectrometry and NMR Facility for the use of the Bruker AVANCE III 500: NIH grant number 1 S10 OD021508-01 and the Texas Materials Institute for the use of the SAXSLAB Ganesha, acquired using an NSF MRI grant CBET-1624659. We thank the Texas Advanced Computing Center (TACC) at the University of Texas at Austin for HPC resources. Funding: This research was primarily supported by the National Science Foundation through the Center for Dynamics and Control of Materials: an NSF Materials Research Science and Engineering Center (NSF MRSEC) under Cooperative Agreement DMR-1720595. E.V.A. acknowledges support from the Welch Regents Chair (F-0046). D.J.M. and T.M.T. also acknowledge support by the Welch Foundation (F-1696 and F-1848). This work was also supported by an NSF Graduate Research Fellowships (DGE-1610403) to S.A.V. and Arnold O. Beckman Postdoctoral Fellowship to Z.M.S.
|Jiho Kang et al. ,Colorimetric quantification of linking in thermoreversible nanocrystal gel assemblies.Sci. Adv.8,eabm7364(2022).DOI:10.1126/sciadv.abm7364
|American Association for the Advancement of Science
|Center for Dynamics and Control of Materials Publications
|Colorimetric quantification of linking in thermoreversible nanocrystal gel assemblies