Curto Yannic, Arora Srishti, Niebuur Bart-Jan, González-García Lola, Kraus Tobias
INM - Leibniz Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany.
Department of Materials Science and Engineering, Saarland University, 66123, Saarbrücken, Germany.
Small. 2025 Apr;21(14):e2411506. doi: 10.1002/smll.202411506. Epub 2025 Mar 3.
This report is about the chemical formation of gels from ultrathin gold nanowires (AuNWs) and the gels' properties. An excess of triphenylphosphine (PPh) initiated the gelation of AuNWs with core diameters below 2 nm and an oleylamine (OAm) ligand shell dispersed in cyclohexane. The ligand exchange of OAm by PPh changes the AuNW-solvent interactions and leads to phase separation of the solvent to form a macroscopic gel. Small angle X-ray scattering and transmission electron microscopy indicate that hexagonal bundles in the original dispersion are dispersed, and the released nanowires entangle. Rheological analyses indicate that the resulting gel is stabilized both by physical entanglement and crosslinking of AuNWs by Van der Waals and π-π interactions. Chemically formed AuNW gels have solid-like properties and crosslinks that distinguish them from highly concentrated non-crosslinked AuNW dispersions. The AuNW gel properties can be tuned via the Au:PPh ratio, where smaller ratios led to stiffer gels with higher storage moduli.
本报告是关于由超薄金纳米线（AuNWs）形成凝胶的化学过程及其性质。过量的三苯基膦（PPh）引发了核心直径小于2纳米且带有分散在环己烷中的油胺（OAm）配体壳层的AuNWs的凝胶化。PPh对OAm的配体交换改变了AuNW与溶剂的相互作用，并导致溶剂相分离形成宏观凝胶。小角X射线散射和透射电子显微镜表明，原始分散体中的六边形束状结构被分散，释放出的纳米线相互缠结。流变学分析表明，所得凝胶通过AuNWs的物理缠结以及范德华力和π-π相互作用交联而得以稳定。化学形成的AuNW凝胶具有类似固体的性质和交联结构，这使其有别于高浓度的非交联AuNW分散体。AuNW凝胶的性质可通过Au:PPh比例进行调节，较小的比例会导致凝胶更硬，储能模量更高。
