在甲醇单水合物中,负线性压缩性和巨大的异型热膨胀
A Dominic Fortes1, Emmanuelle Suard, Kevin S Knight
1Department of Earth Sciences, University College London (UCL), Gower Street, London WC1E 6BT, UK. andrew.fortes@ucl.ac.uk
Science (New York, N.Y.)
|February 12, 2011
概括
研究人员发现了一种罕见的分子晶体,具有负线性压缩性 (NLC) 和负热膨胀 (NTE). 这种不寻常的材料在压力下膨胀,为先进的材料设计提供了新的可能性.
科学领域:
- 材料科学 材料科学 材料科学
- 晶体学 晶体学是指结晶学.
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 大多数材料在液压压力下收缩.
- 材料在压力下膨胀的负线性压缩性 (NLC) 是罕见的,特别是在晶体固体中.
- 了解分子晶体中的NLC对于开发新材料至关重要.
研究的目的:
- 在一个简单的分子晶体中发现和描述内在负线性可压缩性 (NLC).
- 为了研究这种NLC材料的热膨胀特性,包括负热膨胀 (NTE).
- 阐明观察到的NLC和NTE行为背后的结构机制.
主要方法:
- 用中子粉衍射分析了水晶结构和压力和温度下的行为.
- 对甲醇和水的化1:1化合物进行了详细的结晶学分析.
主要成果:
- 该研究确定并证实了NLC和高度异构的热膨胀,包括NTE沿NLC轴,在研究的分子晶体中.
- 结构分析显示,由基-水链和甲基组形成的,由基连接的圆柱体,对NLC/NTE行为负责.
- 这种材料在受到水静压缩时,沿着特定的轴展现膨胀.
结论:
- 一个简单的分子晶体,甲醇和水的化1:1化合物,表现出内在的NLC和NTE.
- 基-水链和甲基组的独特结构布局决定了观察到的异构性行为.
- 这一发现为设计具有对机械和热刺激异常反应的材料开辟了道路.
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