Diffusion in Circularly Ordered Mesoporous Silica Fibers
Diffusion in Circularly Ordered Mesoporous Silica Fibers
复制标题
DOI：
10.1021/jp1102912
复制
发表时间：
2011-04
影响因子：
3.7
通讯作者：
Hatem M Alsyouri;Oliver C. Gobin;A. Jentys;J. Lercher
中科院分区：
文献类型：
--
作者：
Hatem M Alsyouri;Oliver C. Gobin;A. Jentys;J. Lercher
研究了正己烷和均三甲苯在环状有序介孔二氧化硅纤维中的传输过程。结合基于复杂层次结构的理论计算和频率响应实验的实验结果，确定了有序介孔二氧化硅纤维中分子传输路径的三条明确的路径，即轴向、切向和径向的扩散，它们都是平行发生的。径向扩散是主要的扩散过程，并受壁内输运的控制。轴向的运移与径向扩散重叠，可以由壁内运移或中孔运移控制。表面的裂纹或缺陷使切向扩散成为可能，这是实验观察到的第三个动力学过程。
Transport processes of n-hexane and mesitylene in circularly ordered mesoporous silica fibers have been investigated. Combining theoretical calculations based on the complex hierarchical structure with experimental results from frequency response experiments, three well-defined pathways for the transport pathways of molecules in the ordered mesoporous silica fibers are identified, that is, diffusion in axial, tangential, and radial directions, all occurring in parallel. The radial diffusion is the dominant process and is governed by intrawall transport. Transport in the axial direction overlaps with the radial diffusion and can be governed by either intrawall or mesopore transport. Cracks or defects at the surface enable diffusion in the tangential direction, which is the third kinetic process experimentally observed.