Concentration fluctuation in alcohol-water mixture : Is the structural aspect of poly-disperse mass-fractal universal?

醇-水混合物的介观结构具有浓度波动或微观非均质性的特征。然而，浓度波动的结构细节和波动的分子来源仍然不清楚。需要对酒精混合物的中尺度结构进行更详细的结构研究。我们以前报道过，通过新发展的小角中子散射强度可视化分析，正丙醇-水混合物的介观结构被用多分散质量-分维来表征。这项研究的目的是检查多分散质量-分维的这种结构方面是否在其他酒精-水混合物中普遍观察到。为此，我们对叔丁醇-水进行了小角中子散射测量。用分形学的方法分析了混合物的浓度波动。利用…对浓度波动的结构进行了可视化更大规模的逆蒙特卡罗技术。对可视化结构的逾渗分析表明，浓度波动具有多分散的质量分数维特征，正丙烷-水混合物的浓度波动也是如此。这些发现有力地表明，多分散质量分维是各种醇-水混合物的共同结构特征。我们还将可视化技术应用于液体Rb-Se和BiBr混合物，以了解这些液体的短程和中程结构。研究发现，Rb-Se混合物的可视化模型结构中存在大量空洞。利用Delaunay简化的空穴分析表明，由于结构中空穴和Se链的化学有序堆积，观测到的预峰对应于浓度-浓度结构因子的预峰。我们强调，介观结构的可视化对于理解各种液体混合物的复杂性是至关重要的。较少

The mesoscale structure of alcohol-water mixtures is characterized by concentration fluctuation or micro-heterogeneity. However the structural details of the concentration fluctuation and the molecular origin of the fluctuation are still obscure. More detailed structural studies on the mesoscale structure of the alcohol mixtures are needed. We reported previously that the mesoscale structure of the 1-propanol-water mixtures was characterized by poly-disperse mass-fractals by means of a newly developed visualization-analysis of small angle neutron scattering intensity. The purpose of this study is to examine whether this structural aspect of the poly-disperse mass-fractals is commonly observed in other alcohol-water mixtures. For this purpose we have carried out small angle neutron scattering measurement on tert-butyl alcohol-water. Concentration fluctuation of the mixture has been analyzed in terms of fractal. Structure of the concentration fluctuation has been visualized by means of a … More large-scale reverse Monte Carlo technique. Percolation analysis of the visualized structure shows that the concentration fluctuation is characterized by poly-disperse mass fractals, which has been found for 1-propano-water mixture. These findings strongly suggest that the poly-disperse mass-fractal is a common structural characteristic in various alcohol-water mixtures.We have also applied the visualization technique to liquid Rb-Se and Bi-Br mixtures in order to understand the short-range and intermediate-range structures of these liquids. It was found that there were many voids in the visualized model structure of Rb-Se mixtures. From the void analysis using Delaunay simplices it has been revealed that the observed pre-peak corresponds to a pre-peak in the concentration-concentration structure factor due to the chemically ordered packing of the voids and Se chains in the structure.We emphasize that the visualization of the mesoscale structure is essentially important to understand the complexity in various liquid mixtures. Less