A NMR technique for the analysis of pore structure: Application to materials with well-defined pore structure

Gallegos, D.P.; Munn, Kevin; Smith, Douglas M.; Stermer, Dorothy L

doi:10.1016/0021-9797(87)90251-7

Cited by 133 publications

(64 citation statements)

References 9 publications

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“…T 2m depends on many factors such as temperature, magnetic field intensity, and the interaction among hydrogens and other possible substances present in the environment [29]. In particular, hydrogens interactions with solid surfaces (for instance dispersed/solubilized polymeric chains and system boundaries) are one of the most important causes of T 2m variation.…”

Section: Surface Effect On T 2mmentioning

confidence: 99%

“…Accordingly, the average relaxation time (T 2m ) of protons will depend on the ratio between the solid surface area (S), proportional to the number of protons close to S, and system volume (V), proportional to the total number of protons belonging to the system, as demonstrated by Brownstein and Tarr [1] in the case of solid porous systems. In particular, the relation between S, V, and the average relaxation time may be represented by [29]:…”

Section: Surface Effect On T 2mmentioning

confidence: 99%

“…Indeed, M represents the ratio between the thickness and the relaxation time of the bound water layer adhering to the solid surface (thus M = /T 2s ). M depends not only on the solid surface chemistry but also on temperature, hydrogenated fluid type, and magnetic field strength [29]. Typically, at 20 MHz, in the temperature range 25-37 °C, polymeric materials are characterized by M values ranging between 10 -7 -10 -5 m/s [31].…”

Section: Surface Effect On T 2mmentioning

confidence: 99%

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Use of low-field NMR for the characterization of gels and biological tissues

et al. 2018

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Section: Surface Effect On T 2mmentioning

confidence: 99%

Section: Surface Effect On T 2mmentioning

confidence: 99%

Section: Surface Effect On T 2mmentioning

confidence: 99%

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Use of low-field NMR for the characterization of gels and biological tissues

et al. 2018

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“…Relaxometry uses the enhanced relaxation of molecules at a pore surface to calculate the pore diameter [3] and normally assumes rapid exchange between molecules at the surface and in the pores. The inverse spin-lattice and spin-spin relaxation rates (1/T 1 and 1/T 2 ) are then proportional to the surface (S) to volume (V) ratio [4] of the porous media, as in Eq.…”

Section: Introductionmentioning

confidence: 99%

Pore surface exploration by NMR

Strange

Mitchell

Webber

2003

Magnetic Resonance Imaging

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A carefully chosen set of experimental techniques applied to porous media characterisation provides results that can be much greater than the sum of the individual parts. The inter-relation and complementarity of a number of techniques will be considered. NMR cryoporometry provides a valuable method of pore size measurement. An NMR method that is more widely used to assess pore dimensions relies on relaxation time analysis of a liquid that fills the pores and the enhanced relaxation that occurs in a liquid at the solid/liquid interface. Thermoporometry, a method based on the application of Differential Scanning Calorimetry (DSC), is closely related to cryoporometry, but employs a different set of assumptions to evaluate pore size distributions. Comparison of the results obtained on the same samples using all these methods together with gas adsorption serves to validate the methods and provide significantly more information about surface-fluid interaction and the behaviour of nano-scale material within pores than each method employed in isolation. Technique developments will be discussed and applications of these methods to ideal silicas will be used to illustrate their power, particularly in combination.

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“…Water can be frozen in narrower pores (cavities in biomacromolecules, RBC membrane, intracellular space or voids between primary particles of nanooxides) at lower temperature that can be described by the Gibbs-Thomson relation for the freezing point depression [18,24,[30][31][32][33] …”

Section: Tablementioning

confidence: 99%

Interaction of unmodified and partially silylated nanosilica with red blood cells

et al. 2007

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Abstract:Interaction of red blood cells (RBCs) with unmodified and partially (50%) silylated fumed silica A-300 (nanosilica) was studied by microscopic, XRD and thermally stimulated depolarisation current (TSDC) methods. Nanosilica at a low concentration C A−300 < 0.01 wt.% in buffered aqueous suspension is characterised by a weak haemolytic effect on RBCs. However, at C A−300 = 1 wt% all RBCs transform into shadow corpuscles because of 100% haemolysis. Partial (one-half) hydrophobization of nanosilica leads to reduction of the haemolytic effect in comparison with unmodified silica at the same concentrations. A certain portion of the TSDC spectra of the buffered suspensions with RBC/A-300 is independent of the amounts of silica. However, significant portions of the low-and high-temperature TSDC bands have a lower intensity at C A−300 = 1 wt% than that for RBCs alone or RBC/A-300 at C A−300 = 0.01 wt.% because of structural changes in RBCs. Results of microscopic and XRD investigations and calculations using the TSDC-and NMR-cryoporometry suggest that the intracellular structures in RBCs (both organic and aqueous components) depend on nanosilica concentration in the suspension.

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A NMR technique for the analysis of pore structure: Application to materials with well-defined pore structure

Cited by 133 publications

References 9 publications

Use of low-field NMR for the characterization of gels and biological tissues

Use of low-field NMR for the characterization of gels and biological tissues

Pore surface exploration by NMR

Interaction of unmodified and partially silylated nanosilica with red blood cells

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