Determination of pore space shape and size in porous systems using NMR diffusometry. Beyond the short gradient pulse approximation

Summary, in English

The influence of finite length gradient pulses on NMR diffusion experiments on liquids

confined to diffuse between two parallel planes is investigated. It is experimentally verified that the pore size decreases when determined using finite gradient pulses if the results are analyzed within the short gradient pulse approximation. The results are analyzed using the matrix formulation. The observed minima in the echo decay profiles are considerably less sharp than theoretical analysis would indicate and we suggest that this is due to the presence of a distribution of pore sizes in the sample. In addition, effects due to the presence of background gradients are discussed. It is argued that effects due to the finite length gradient pulses are relatively minor and in realistic applications the effects due to inhomogeneities in pore sizes and effects due to background gradients will constitute more serious problems in pore size determinations by means of NMR diffusometry. (C) 2003 Elsevier Science (USA). All rights reserved.

• Författare: W S Price; P Stilbs; Olle Söderman
• Avdelning/ar: Fysikalisk kemi
• Publiceringsår: 2003
• Språk: Engelska
• Sidor: 139-143
• Publikation/Tidskrift/Serie: Journal of Magnetic Resonance
• Volym: 160
• Issue: 2
• Länkar: http://dx.doi.org/10.1016/S1090-7807(02)00134-9
• Dokumenttyp: Artikel i tidskrift
• Förlag: Academic Press
• Ämne: Physical Chemistry
• Nyckelord: NMR diffusometry; Diffusion between planes; Finite gradient pulses; Pore size distribution effects; Background gradients
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1096-0856