Multiscale Approach to the Structural Study of Water Confined in MCM41
Multiscale Approach to the Structural Study of Water Confined in MCM41
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DOI：
10.1021/jp9062109
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发表时间：
2009-12-17
影响因子：
3.3
通讯作者：
Ricci, M. A.
中科院分区：
文献类型：
--
作者：
Mancinelli, R.;Imberti, S.;Ricci, M. A.
我们提出了一个协议，同时结构表征的限制流体和限制基板，沿着与提取的网站网站对相关函数的液体的兴趣。这是基于中子衍射实验，利用可行的同位素替代技术，通过数值粗粒化计算和原子模拟分析。在MCM 41-S-15中限制水的情况下，描述了实验过程的所有微妙之处、所需的辅助测量以及针对真实的实验和样品定制数字代码的方法。特别地，定量地讨论了中子截面中的排斥体积效应和液体-衬底互相关项的相关性。水的微观结构得到的结果证明了孔隙内的分子的非均匀分布，与水-基质氢键的存在下，和一个强大的扭曲的水-水的径向分布函数相对于那些散装水延伸至少高达三个水化层。
We present a protocol for simultaneous structural characterization of a confined fluid and the confining Substrate, along with the extraction of site-site pair correlation functions of the liquid of interest. This is based on neutron diffraction experiments, exploiting where feasible the isotopic substitution technique, analyzed through numerical coarse graining calculations and atomistic simulations. All of the subtleties of the experimental procedure, the needed ancillary measurements, and the recipe for tailoring the numerical codes to the real experiment and sample are described in the case of water confined in MCM41-S-15. In particular the excluded volume effects and the relevance of liquid-Substrate cross-correlation terms in the neutron cross section are quantitatively discussed. The results obtained for the microscopic structure of water evidence a non-homogeneous distribution of molecules within the pore, with the presence of water-substrate hydrogen bonds, and a strong distortion of the water-water radial distribution functions with respect to those of bulk water extending at least up to three hydration layers.