期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 140, 期 10, 页码 3652-3662出版社
AMER CHEMICAL SOC
DOI: 10.1021/jacs.7b12175
关键词
-
资金
- National Science Foundation (NSF) [CMMI-1344562]
- European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme [741767]
- Packard Foundation
- NSF GRFP grant [DGE-1144153]
- NSF MRSEC (Materials Research Science and Engineering Centers) program [DMR-1719875]
- Cornell University
- Weill Institute
- Kavli Institute at Cornell
- National Science Foundation
- National Institutes of Health/National Institute of General Medical Sciences under NSF award [DMR-1332208]
- King Abdullah University of Science and Technology (KAUST) [KUS-C1-018-02]
- NSF-MRI grant [CHE-1531632]
- U.S. Fulbright Scholar Program
- [NSF-MRI-1429155]
Magic-sized clusters (MSCs) are renowned for their identical size and closed-shell stability that inhibit conventional nanoparticle (NP) growth processes. Though MSCs have been of increasing interest, understanding the reaction pathways toward their nucleation and stabilization is an outstanding issue. In this work, we demonstrate that high concentration synthesis (1000 mM) promotes a well-defined reaction pathway to form high-purity MSCs (>99.9%). The MSCs are resistant to typical growth and dissolution processes. On the basis of insights from in situ X-ray scattering analysis, we attribute this stability to the accompanying production of a large (>100 nm grain size), hexagonal organic-inorganic mesophase that arrests growth of the MSCs and prevents NP growth. At intermediate concentrations (500 mM), the MSC mesophase forms, but is unstable, resulting in NP growth at the expense of the assemblies. These results provide an alternate explanation for the high stability of MSCs. Whereas the conventional mantra has been that the stability of MSCs derives from the precise arrangement of the inorganic structures (i.e., closed-shell atomic packing), we demonstrate that anisotropic clusters can also be stabilized by self-forming fibrous mesophase assemblies. At lower concentration (<200 mM or >16 acid-to-metal), MSCs are further destabilized and NPs formation dominates that of MSCs. Overall, the high concentration approach intensifies and showcases inherent concentration-dependent surfactant phase behavior that is not accessible in conventional (i.e., dilute) conditions. This work provides not only a robust method to synthesize, stabilize, and study identical MSC products but also uncovers an underappreciated stabilizing interaction between surfactants and clusters.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据