Topological analysis of non-granular, disordered porous media: determination of pore connectivity, pore coordination, and geometric tortuosity in physically reconstructed silica monoliths
Topological analysis of non-granular, disordered porous media: determination of pore connectivity, pore coordination, and geometric tortuosity in physically reconstructed silica monoliths
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DOI：
10.1039/c5nj02814k
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发表时间：
2016-01-01
影响因子：
3.3
通讯作者：
Tallarek, Ulrich
中科院分区：
文献类型：
--
作者：
Hormann, Kristof;Baranau, Vasili;Tallarek, Ulrich
获得足够的知识多孔介质的形态是至关重要的，以确保其持续成功的支持结构的应用，依赖于有效的质量传输。多孔介质的物理重建为其形态的准确表征提供了最佳基础，但有意义的描述符的识别并不简单，特别是对于整体材料，其连续的固相和开孔网络抵抗适用于颗粒介质的镶嵌方案。在这项工作中，我们专注于一个几乎没有调查的组成部分，二氧化硅整料的形态，即拓扑结构的流体动力学可访问的大孔空间。我们提出并应用合适的方法来确定孔的连通性，孔的协调，和几何曲折度在四个二氧化硅整体样品后，通过共聚焦激光扫描显微镜的大孔空间的物理重建。通过中轴分析追踪孔隙连通性，而通过最大内接球方法将开放的大孔隙空间划分为单个孔隙和孔喉后评价孔隙协调性。通过中轴分析以及通过传播方法确定几何弯曲度，所述传播方法将从重建的中心点到孔隙空间中的每一个其他点的测地线距离映射。所呈现的结果提供了一个全面的描述二氧化硅整体拓扑结构以及定量数据的孔隙网络模型的构建。所提出的分析方法适用于任何多孔材料，可以在所需的分辨率进行物理重建。
Gaining adequate knowledge on the morphology of porous media is critical to ensuring their continued success as support structures in applications that rely on efficient mass transport. The physical reconstruction of a porous medium provides the optimum basis for an accurate characterization of its morphology, yet the identification of meaningful descriptors is not straightforward, especially not for monolithic materials, whose continuous solid phase and open pore network resist the tessellation schemes applicable to granular media. In this work, we focus on a hardly investigated component of silica monolith morphology, namely the topology of the hydrodynamically accessible macropore space. We propose and apply suitable methods to determine pore connectivity, pore coordination, and geometric tortuosity in four silica monolith samples after physical reconstruction of their macropore space by confocal laser scanning microscopy. Pore connectivity is traced by medial axis analysis, whereas pore coordination is evaluated after compartmentalization of the open macropore space into individual pores and pore throats by a maximum inscribed spheres approach. The geometric tortuosity is determined by medial axis analysis as well as by a propagation method that maps the geodesic distance from the center point of a reconstruction to every other point in the pore space. The presented results provide a comprehensive description of silica monolith topology as well as quantitative data for the construction of pore network models. The proposed analysis methods are applicable to any porous material that can be physically reconstructed at the required resolution.