Abstract
Imaging methods, such as micro-focus X-ray (MFX) imaging and magnetic resonance imaging (MRI), have greatly improved our ability to characterize the highly complex internal structures of porous media. MFX imaging and MRI are now both able to provide maps of the spatial distribution of local av. accessible porosity for mesoporous media over macroscopic length scales (>.apprx.10 micro m). A methodol. for obtaining this type of information by MFX imaging is described here. For relatively chem. homogeneous materials, conventional 1H MRI is also able to provide a map of the spatial distribution of local av. pore size. However, there are limitations on the type of materials that may be studied using 1H MRI and the range of information that may be obtained by utilizing only one technique alone. For mesoporous materials, MFX imaging alone cannot currently map the spatial distribution of pore size. However, in this work it has been shown that the already extensive capabilities of MFX imaging may be even further enhanced by a combination of it with the more traditional techniques of mercury porosimetry and nitrogen sorption. The methodol. described here has enabled the detn. of the spatial distributions of both the local av. (over length scales .apprx.10 micro m) porosity and pore size distribution for mesoporous and macroporous materials over macroscopic length scales. The methodol. is also suitable for quant. application to interesting chem. heterogeneous materials, such as mixed oxide absorbents or coked catalysts, not amenable to conventional 1H MRI. [on SciFinder (R)]
Original language | English |
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Pages (from-to) | 3467-3481 |
Number of pages | 15 |
Journal | Physical Chemistry Chemical Physics |
Volume | 4 |
Issue number | 14 |
Publication status | Published - 2002 |
Keywords
- Pore
- pore structure x ray imaging nitrogen adsorption mercury porosimetry
- Pore size distribution
- Surface area (characterization of porous solids using combination of nitrogen sorption
- Fractals
- characterization of porous solids using combination of nitrogen sorption
- electron microscopy and microfocus X-ray imaging)
- Porous materials (macroporous
- microfocus
- Adsorption
- mercury porosimetry
- Porous materials (mesoporous
- Electron microscopy
- Pore structure
- Imaging (x-ray