Xenon porometry: a novel method for the derivation of pore size distributions.
Xenon porometry is a novel method used for characterizing porous materials by the (129)Xe nuclear magnetic resonance of xenon gas. With the method, the diffusion of gas is slowed down by immersing the material in a medium, which can be in liquid or solid state during measurements. Because of slow diffusion, the signal of a xenon atom is characteristic of the properties of only one pore, and the composite signal of all atoms represents the distribution of properties. The method is especially applicable for determining pore size distribution because the chemical shifts of two different xenon signals (one from liquid and the other from gas pockets in solid) are dependent on pore size. Therefore, the shapes of these signals represent pore size distribution function. In addition, the porosity of the material can be determined by comparing the intensities of two signals. This article focuses on describing xenon signals observed from gas pockets in a solid medium, which has turned out to be most convenient for pore size determination.
Telkki
Ville-Veikko
VV
NMR Research Group, Department of Physical Sciences, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland.
Lounila
Juhani
J
Jokisaari
Jukka
J
D004058:Diffusion; D005615:Freezing; D005740:Gases; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D016062:Porosity; D014979:Xenon Isotopes / Q000737:chemistry
D005740:Gases; D014979:Xenon Isotopes