Restricted Diffusion and Molecular Exchange Processes in Porous Media as Studied by Pulsed Field Gradient NMR

Skirda, V. D.; Филиппов, А. В.; Sagidullin, A.; Mutina, Albina; Archipov, R. V.; Pimenov, G. G.

doi:10.1007/1-4020-4382-1_12

Cited by 7 publications

(12 citation statements)

References 28 publications

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“…The third NMR technique was tau-scanning experiment proposed by our group [4]. The idea of the technique is to obtain information about IMFG distribution in porous media by carrying out an experiment that is in some sense opposite to the PFG NMR.…”

Section: Methodsmentioning

confidence: 99%

“…The idea is to obtain diffusion decays in the wide range of diffusion times and to analyze D s (t d ) dependence of the average self-diffusion coefficient (SDC) on diffusion time. The features of D s (t d ) behavior provide information about porous sizes and porous space permeability [4,8].…”

Section: Methodsmentioning

confidence: 99%

“…Three NMR techniques were used: classical PFG NMR approach with 13-interval pulse sequence [10], DDif experiment [16] and tau-scanning experiment [4]. All studies were done on the NMR diffusometer with the proton frequency 300 MHz, maximum value of the external magnetic field gradient (in case it was applied) being 30 T/m.…”

Section: Methodsmentioning

confidence: 99%

“…The problem of internal field in porous media is discussed in a number of theoretical works also [18][19][20], but reasonable data are obtained only for the model systems (sphere pack, regular geometry porous space, etc.). In the present work, we continue our study of IMFG distribution in porous media by the technique we called tau-scanning experiment [4] that will be described under methods in detail.…”

Section: Introductionmentioning

confidence: 99%

“…Nuclear magnetic resonance (NMR) is one of the powerful techniques to study porous media properties [1][2][3][4][5][6][7][8][9][10][11][12][13]. Classical NMR techniques of porous media morphology and geometry study are based, mostly, on the use of external magnetic field gradients [7][8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Porous media characterization by PFG and IMFG NMR

Mutina¹,

Skirda²

2007

Journal of Magnetic Resonance

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Porous media characterization by PFG and IMFG NMR

Mutina¹,

Skirda²

2007

Journal of Magnetic Resonance

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Solvent diffusion in silica/poly[styrene‐co‐(acrylic acid)] core‐shell microspheres by pulsed field gradient NMR techniques

Jiang

Yang

et al. 2013

J of Applied Polymer Sci

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Polymer‐coated SiO2 particles are prepared by precipitation of poly[styrene‐co‐(acrylic acid)] on SiO2 microspheres through an improved phase inversion method. The diffusion resistance of the polymer membrane was considered to be the critical reason for producing tailor‐made polyethylene by catalysts supported on these polymer‐coated particles. This paper employs pulsed field gradient NMR (PFG‐NMR) to distinguish diffusion of n‐hexane in different regimes, i.e., in the space between each particle, the pores in SiO2 and the polymer shell, by their respective diffusion coefficients. By varying the observation time, the time scale of the molecular exchange is discussed. A three‐region ansatz was used to interpret the exchange and diffusion in polymer‐coated SiO2 system, and was compared with results acquired with noncoated particles. At long diffusion times, the mean‐squared displacement, and thus the averaged self‐diffusion coefficient, of hexane in the system of polymer‐coated SiO2 particles is significantly reduced. The PSA membrane is identified as an efficient barrier against molecular exchange between the pores in SiO2 and the intraparticle space. Consistently, the relaxation measurements indicated that the mobility of n‐hexane molecules, especially the rotation of n‐hexane, was limited by the PSA membrane. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40160.

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Self‐diffusion in a hyaluronic acid–albumin–water system as studied by NMR

Филиппов

Artamonova

Rudakova

et al. 2012

Magnetic Reson in Chemistry

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Hyaluronic acid (HA) is an anionic biopolymer that is present in many tissues and can be involved in cancerous neoformations. HA can form complexes with proteins (particularly, serum albumin) in the body. However, HA structures and processes involving HA have not been extensively studied by NMR because the molecule's rigid structure makes these studies problematic. In the current work, self-diffusion of HA and bovine serum albumin (BSA), and water in solutions was measured by (1)H pulsed field gradient NMR (PFG NMR) with a focus on the HA-BSA-D2O systems at various concentrations of BSA and HA. It was shown that in the presence of even a small amount of HA, the self-diffusion coefficient (SDC) of BSA decreases. To explain this fact, three hypotheses were proposed and analyzed. The first one was based on the effect of slowing down of water mobility in the presence of HA. The second hypothesis suggested an effect of mechanical collisions of BSA with HA molecules. The third hypothesized that BSA and HA molecules form a complex where BSA molecules reduced in mobility. It was shown that the third mechanism is the most likely. The state of the BSA molecules in the BSA-HA-D2O system corresponds to a 'fast exchange' condition from the NMR point of view: BSA molecules reside in the 'free' and 'bound' (with HA) states for much shorter time than the diffusion time of the PFG NMR experiment, 7 ms. The fractions of 'bound' BSA molecules in the BSA-HA complex were estimated.

show abstract

Restricted Diffusion and Molecular Exchange Processes in Porous Media as Studied by Pulsed Field Gradient NMR

Cited by 7 publications

References 28 publications

Porous media characterization by PFG and IMFG NMR

Porous media characterization by PFG and IMFG NMR

Solvent diffusion in silica/poly[styrene‐co‐(acrylic acid)] core‐shell microspheres by pulsed field gradient NMR techniques

Self‐diffusion in a hyaluronic acid–albumin–water system as studied by NMR

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