Characterisation of porous solids using integrated nitrogen sorption and mercury porosimetry
Characterisation of porous solids using integrated nitrogen sorption and mercury porosimetry
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DOI：
10.1016/j.ces.2003.09.017
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发表时间：
2004-01-01
影响因子：
4.7
通讯作者：
Riley, SN
中科院分区：
文献类型：
--
作者：
Rigby, SP;Fletcher, RS;Riley, SN
两种不同的技术，氮吸附和压汞法，这是通常完全分开使用，已被集成到同一个实验，以改善从这两种方法获得的信息。氮吸附等温线已经运行之前和之后的汞孔隙率实验上相同的样品。该实验已经揭示，对于特定类型的溶胶-凝胶二氧化硅催化剂载体，截留的汞仅限于材料中非常大的孔。光学显微镜研究表明，包埋汞的空间分布是高度不均匀的。这些结果表明，材料中的汞截留是由涉及孔结构中的宏观（> 0.1 mm）不均匀性的机制引起的。这些发现与通常的假设相冲突，通常在模拟孔隙率的基础上随机孔隙键网络模型。这项新工作表明，结合涉及正确的汞收缩机制的计算机模拟，汞孔隙率测定法和氮吸附可用于研究中孔材料内所有孔径的空间分布。渗滤分析的氮吸附数据，汞截留之前和之后获得的，允许各种大小的孔隙的空间配置的广泛功能，以确定。这里报告的结果也支持使用新的，半经验的替代品的Washburn方程来分析原始汞孔隙率数据，而不是传统的方法。(C)2003 Elsevier Ltd.保留所有权利。
The two different techniques of nitrogen sorption and mercury porosimetry, which are generally utilised completely separately, have been integrated into the same experiment to improve upon the information obtained from both methods. Nitrogen sorption isotherms have been run both before and after a mercury porosimetry experiment on the same sample. This experiment has revealed that for a particular type of sol-gel silica catalyst support the entrapped mercury is confined to only the very largest pores in the material. Light micrograph studies have shown that the spatial distribution of entrapped mercury is highly heterogeneous. These results suggest that mercury entrapment within the material is caused by a mechanism involving macroscopic ( > 0.1 mm) heterogeneities in the pore structure. These findings conflict with the usual assumptions generally made in simulations of porosimetry based on random pore bond network models. The new work has shown that, in conjunction with computer simulations involving the correct mercury retraction mechanism, mercury porosimetry and nitrogen sorption can be used to study the spatial distribution of all pore sizes within a mesoporous material. A percolation analysis of the nitrogen sorption data, obtained both before and after mercury entrapment, allowed broad features of the spatial disposition of variously sized pores to be determined. The results reported here also support the use of new, semi-empirical alternatives to the Washburn Equation to analyse raw mercury porosimetry data, rather than the traditional approach. (C) 2003 Elsevier Ltd. All rights reserved.