在受控溶剂回火/干燥条件下的Pt3Cu2纳米八面体组件中观察到可逆的Kirkwood-Alder过渡
Jun Zhang1, Zhiping Luo, Benjamin Martens
1Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, USA.
Journal of the American Chemical Society
|July 31, 2012
概括
研究人员在铜纳米八面体中观察到一个柔软的Kirkwood-Alder过渡. 这些纳米粒子自组装成一个独特的开放的bcc超级晶格结构,在溶剂蒸发过程中展示了可逆变化.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 晶体学 晶体学是指结晶学.
背景情况:
- 与球形纳米粒子相比,非球形纳米粒子提供了独特的组装可能性.
- 了解纳米粒子自我组装对于设计先进材料至关重要.
- 柯克伍德-阿尔德过渡是体系统中已知的现象.
研究的目的:
- 为了研究非球形白金-铜 (Pt(3) Cu(2)) 纳米八面体的自我组装行为.
- 描述由此产生的超级网格结构及其形成机制.
- 探索组装过程的动态,包括过渡和可逆性.
主要方法:
- 传输电子显微镜 (TEM) 断层扫描与3D重建.
- 基于同步镜的现场放牧发生小角度X射线散射 (GISAXS).
- 在现场和实时GISAXS观察溶剂蒸发过程中的动态过程.
主要成果:
- Pt(3) Cu(2) 纳米八面体自组装成一个开放的以身体为中心的立方体 (bcc) 超级网格,排列端到端.
- 观察到一种"纳米八面体结晶",被确定为软基克伍德-阿尔德过渡.
- 超格子常数在溶剂回火和蒸发/干燥周期期间显示可逆变化.
结论:
- 非球状Pt(3) Cu(2) 纳米面体可以通过柔软的柯克伍德-阿尔德过渡形成有序的超级网格.
- 观察到的开放的BCC结构和可逆的超级网格变化为纳米粒子组装提供了新的途径.
- 这项研究证明了工程纳米粒子在创造动态,响应性材料方面的潜力.
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