In Situ UV/Vis, SAXS, and TEM Study of Single-Phase Gold Nanoparticle Growth
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- 作者：Hilmar Koerner ; Robert I. MacCuspie ; Kyoungweon Park ; Richard A. Vaia
- 刊名：Chemistry of Materials
- 出版年：2012
- 出版时间：March 27, 2012
- 年：2012
- 卷：24
- 期：6
- 页码：981-995
- 全文大小：738K
- 年卷期：v.24,no.6(March 27, 2012)
- ISSN：1520-5002
文摘
Given the diverse scientific and technological applications of gold nanoparticles (Au鈥塏Ps), understanding the impact of macromolecular additives on the distribution of size, shape, and composition is crucial to ensure reproducibility and lower production cost. In situ measurement of the evolution of these distributions challenges current techniques; however, it is critical for in-line manufacturing controls. Using mild Au(I) reduction by tert-butylamine-borane in toluene, the utility and limitations of SAXS, UV/Vis spectroscopy, and TEM are considered by comparing the mean nanoparticle size, size distribution, and relative number density. Individually, these techniques are insufficient to follow these parameters through the initial process of nucleation and growth; either providing insufficient information on the number of particles (UV/Vis), introducing artifacts (TEM), or not providing a unique solution for the shape of the distribution (SAXS). However, when used in conjunction, especially SAXS calibrated with TEM of reaction aliquots, the time evolution of these parameters can be quantified. For the single-phase Au鈥塏P synthesis with Au(I) and mild reductants, four distinct experimental regions are revealed that entail two growth mechanisms, which complement previous discussions of single-mode growth kinetics. The kinetics of Au(I):borane reactions are dependent on the Au precursor/reductant ratio and the thiol capping agent length, when reductant concentration is low. The final reaction products exhibit an LSW size distribution.