Quantification of the heterogeneity of particle packings.
Quantification of the heterogeneity of particle packings.
复制标题
颗粒堆积的异质性的量化。
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
H. Herrmann
中科院分区：
文献类型：
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作者：
Iwan Schenker;F. Filser;L. Gauckler;T. Aste;H. Herrmann
凝聚胶体颗粒的微观结构受颗粒表面电势的影响很大，颗粒间势用Derjaguin-Landau-Verweg-Overbeek理论描述。根据其价值的不同，所得到的微结构要么更“均匀”，要么更“不均匀”，体积分数相等。然而，对结构的异质性程度(DOH)进行适当的量化还不存在。在这项工作中，研究和比较了对微结构的DOH进行量化和分类的方法。用布朗动力学模拟产生的粒子填充对三种方法进行了评估：(1)孔径分布，(2)密度涨落方法，(3)Voronoi体积分布。每种方法都通过拟合函数中的参数或积分来提供标量测量，该标量测量与微观结构的异质性相关，从而允许定量地捕捉颗粒材料的DOH。此外，对两个结构之间密度波动的差异的分析还允许详细确定非均质性差异最显著的长度尺度。
The microstructure of coagulated colloidal particles, for which the interparticle potential is described by the Derjaguin-Landau-Verweg-Overbeek theory, is strongly influenced by the particles' surface potential. Depending on its value, the resulting microstructures are either more "homogeneous" or more "heterogeneous," at equal volume fractions. An adequate quantification of a structure's degree of heterogeneity (DOH), however, does not yet exist. In this work, methods to quantify and thus classify the DOH of microstructures are investigated and compared. Three methods are evaluated using particle packings generated by Brownian dynamics simulations: (1) the pore size distribution, (2) the density-fluctuation method, and (3) the Voronoi volume distribution. Each method provides a scalar measure, either via a parameter in a fit function or an integral, which correlates with the heterogeneity of the microstructure and which thus allows to quantitatively capture the DOH of a granular material. An analysis of the differences in the density fluctuations between two structures additionally allows for a detailed determination of the length scale on which differences in heterogeneity are most pronounced.