title: Determination of the structure of wood from the self-diffusion probability densities of a fluid observed by position-exchange NMR spectroscopy.
abstract: Self-diffusion of a fluid absorbed in a solid matrix is restricted by the walls of the matrix. We demonstrate that the local self-diffusion probability densities (propagators) of fluid molecules can be measured by position-exchange nuclear magnetic resonance spectroscopy (POXSY), and analysis of the shape of the propagators reveals the local size-distributions of the voids in the matrix. We also show that, in the case of rectangular voids, size-distribution can be calculated in a long diffusion-time limit without any assumptions about the shape of the distribution. Pinus sylvestris pine wood was used as a sample material in the experiments, and the results show that this method gives detailed information about the structure of wood.
authors.affiliation: NMR Research Group, Department of Physical Sciences, University of Oulu, PO Box 3000, FIN-90014, Finland. ville-veikko.telkki@oulu.fi
authors.forename: Ville-Veikko
authors.initials: VV
authors.lastname: Telkki
authors.forename: Jukka
authors.initials: J
authors.lastname: Jokisaari
mesh_terms: D000465:Algorithms; D004058:Diffusion; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008697:Methane / Q000737:chemistry; D041605:Pinus sylvestris / Q000737:chemistry; D016062:Porosity; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014934:Wood / Q000737:chemistry*
chemical_list: D014867:Water; D008697:Methane