六合旋转器阶段的结构:X射线光谱和分子动力学模拟的结合
Stephen A Burrows1, E Emily Lin1, Diana Cholakova2
1Centre for Sustainable Engineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, U.K.
The journal of physical chemistry. B
|August 30, 2023
概括
这项研究揭示了使用X射线衍射和分子动力学模拟的alkane-water接口的n-hexadecane面部中心的正方形RI旋转相. 这为这个稳定的旋转器阶段提供了完整的单元细胞信息.
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.
- 物理化学 物理化学
背景情况:
- 旋转器相是旋转无序的塑料晶体.
- 基旋转相可以在基-水接口上形成,n-基在纯系统中表现出转移稳定性,但在接口上表现出稳定性.
- 之前的X射线衍射研究仅为基旋转器相提供了部分单元细胞信息.
研究的目的:
- 为了提供明确的证据和完整的单元细胞信息,以面部为中心的 orthorhombic RI n-hexadecane 的旋转相在-水接口.
- 使用同步射线射线衍射和分子动力学 (MD) 模拟的组合进行详细的结构分析.
- 开发RI阶段的晶体信息文件 (CIF) 模型.
主要方法:
- 在由Brij C10和Tween 40表面活性剂稳定的六甘乳液上进行了同步龙X射线衍射.
- 使用威廉姆斯7B力场进行的分子动力学 (MD) 模拟用于纯六甲基.
- 来自衍射数据的单元细胞尺寸与MD模拟的分子方向相结合.
主要成果:
- 从实验光谱中获得了面部为中心的正方形RI旋转器相的明确证据.
- MD模拟成功预测了RI阶段的晶体结构,并重现了晶体到旋转器的过渡.
- 创建了一个全面的单元细胞模型,将每个分子表示为四个旋转位置的叠加,占用率为25%.
- 从模型中计算的粉末衍射光谱与实验数据有很好的一致性.
结论:
- 该研究成功地确定了n-hexadecane在接口上的RI旋转相的完整单元细胞信息.
- 在X射线衍射和MD模拟的结合方法提供了一个强大的方法来表征旋转器相.
- 开发的CIF模型是了解这种塑料晶体相的结构和性能的宝贵资源.
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