Fakultät Physik/DELTA , Technische Universität Dortmund , 44227 Dortmund , Germany.
Department of Materials Science and Chemical Engineering , Stony Brook University , Stony Brook , New York 11794 , United States.
Langmuir. 2018 Apr 24;34(16):4811-4819. doi: 10.1021/acs.langmuir.7b03984. Epub 2018 Apr 11.
Room-temperature ionic liquids (RTILs) can be used as electrosterical stabilizers for nanoparticles without adding stabilizing agents. However, the nanoparticle stability and its mechanisms are still in discussion. We deposited preformed 2 nm ±0.6 nm silver clusters into the ionic liquid CMIM PF using in situ UV/vis absorption to monitor the deposition process. The time- and temperature-dependent cluster aggregation process was studied with ex situ UV/vis absorption spectroscopy analyzed with electrodynamic calculations using generalized Mie theory. On an atomistic level, the sample structure was investigated using EXAFS and a neural network based analysis of XANES. The combination of all methods shows that an aggregation of the original 2 nm clusters without coalescence takes place, which can be controlled or stopped by choosing an appropriate sample temperature. This approach allows the controlled production of chainlike cluster aggregates in RTIL, promising for a number of applications.
室温离子液体（RTILs）可作为纳米粒子的静电稳定剂使用，而无需添加稳定剂。然而，纳米粒子的稳定性及其机制仍在讨论中。我们使用原位 UV/vis 吸收将预先形成的 2nm±0.6nm 银团簇沉积到离子液体 CMIM PF 中，以监测沉积过程。使用广义米氏理论的电动计算对具有外部 UV/vis 吸收光谱分析的时变和温度依赖的团簇聚集过程进行了研究。在原子水平上，使用 EXAFS 和基于神经网络的 XANES 分析研究了样品结构。所有方法的结合表明，原始 2nm 团簇的聚集而没有聚结发生，通过选择适当的样品温度可以控制或停止这种聚集。这种方法允许在 RTIL 中控制链状团簇聚集物的产生，这对许多应用具有前景。
