Peculiarities in the Water Adsorption and Morphology of Carbon Chars Assessed by NMR

Odintsov, B. M.; Temnikov, A.N.; Belford, R. Linn; Ceroke, P.J.; Idiyatullin, Z. Sh.; Clarkson, R. B.

doi:10.1006/jcis.2000.7286

Cited by 3 publications

(4 citation statements)

References 23 publications

(24 reference statements)

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“…1 of the paper by Odintsov et al (1), the large sharp peak A is due to the fast exchange of strong interactions between neighboring molecules in bulk liquid water. In the char, bulk water is "interstitial" water between the char particles and "unbound" water above the perturbed layer, the thickness of which is not known for this type of carbon.…”

mentioning

confidence: 89%

“…Disappearance of the peak A at −10 • C (Fig. 2, in Odintsov et al (1)) is due either to an insufficiently pure water sample used for suspension or to the capability of the char surface to induce heterogeneous freezing of ice. Slow diminution of the peak B with temperature was due to more and more water molecules from the perturbed layer becoming trapped in lattice of ice.…”

mentioning

confidence: 97%

“…In their paper, Odintsov et al (1) described how the data obtained from 1 H NMR measurements have been used for explanation of the morphology of carbon chars and the adsorption features of water in the char pores. One of their findings was that water in micropores remained unfrozen (retained its high local mobility) at −80 • C and even lower.…”

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confidence: 99%

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Comment on “Peculiarities in the Water Adsorption and Morphology of Carbon Chars Assessed by NMR”

Bogdan¹

2001

Journal of Colloid and Interface Science

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confidence: 89%

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Comment on “Peculiarities in the Water Adsorption and Morphology of Carbon Chars Assessed by NMR”

Bogdan¹

2001

Journal of Colloid and Interface Science

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“…Six individual project reports to the DOE described the instrumentation, techniques, theory, and typical results. [1][2][3][4][5][6] Sixteen peerreviewed articles [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] contain details and discussions of parts of this work. These reports describe the first observations of solid-liquid electron spin density transfer, showing a transient chemical interaction between water molecules and particulate surfaces in an aqueous slurry of carbonaceous char particles by a proton pulsed Dynamic Nuclear Polarization (DNP) technique at low magnetic field.…”

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confidence: 99%

Coal and Char Studies by Advanced Emr Techniques

Belford¹,

Clarkson²,

Nilges³

et al. 2001

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Advanced electronic magnetic resonance (EMR) as well as nuclear magnetic resonance (NMR) methods have been used to examine properties of coals, chars, and molecular species related to constituents of coal. During the span of this grant, progress was made on construction and applications to coals and chars of two high frequency EMR systems particularly appropriate for such studies -48 GHz and 95 GHz electron magnetic resonance spectrometer, on new low-frequency dynamic nuclear polarization (DNP) experiments to examine the interaction between water and the surfaces of suspended char particulates in slurries, and on a variety of proton nuclear magnetic resonance (NMR) techniques to measure characteristics of the water directly in contact with the surfaces and pore spaces of carbonaceous particulates. EXECUTIVE SUMMARYThe main advanced magnetic resonance methods employed over the period of this project were (1) W-band (100 GHz) electronic magnetic resonance (EMR) spectroscopy to provide an analytical tool to discriminate among very similar chemical species that are constituents of coals and closely related materials such as chars, (2) construction of a U-band (50 GHz) EMR spectrometer to aid such analysis by filling the wide gap between W-band and the lower available frequencies, (3) very low frequency pulsed dynamic nuclear polarization (DNP) spectroscopy for study of the interfaces between coal-like particles and the water medium in which they are suspended, and (4) a variety of proton nuclear magnetic resonance (NMR) techniques to measure characteristics of the water in contact with particle surfaces and pore spaces.This project was carried out over a forty-two month period. Six individual project reports to the DOE described the instrumentation, techniques, theory, and typical results.1-6 Sixteen peerreviewed articles 7-22 contain details and discussions of parts of this work. These reports describe the first observations of solid-liquid electron spin density transfer, showing a transient chemical interaction between water molecules and particulate surfaces in an aqueous slurry of carbonaceous char particles by a proton pulsed Dynamic Nuclear Polarization (DNP) technique at low magnetic field. In a second study, by use of Fourier Transform PulsedField-Gradient spin-echo NMR spectroscopy several self-diffusion coefficients were obtained in aqueous char suspensions corresponding to different mobilities of water molecules in the porous structures. It was concluded that the short-range nuclear-electronic interactions in pore space have the dominant effect on DNP enhancement in char suspensions. In another study, a strong particle size influence on NMR transverse proton relaxation in aqueous suspensions of these newly synthesized chars was found.Multifrequency EMR spectroscopy can be a powerful tool in understanding details of the chemical species present in native and processed coals, coal constituents, and synthetic carbonaceous materials like chars. High frequency EMR is especially informative because of...

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Water vapor adsorption on chars and active carbons–oxygen sensors prepared from a tropical tree wood

Vartapetyan

Волощук

Buryak

et al. 2005

Carbon

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Peculiarities in the Water Adsorption and Morphology of Carbon Chars Assessed by NMR

Cited by 3 publications

References 23 publications

Comment on “Peculiarities in the Water Adsorption and Morphology of Carbon Chars Assessed by NMR”

Comment on “Peculiarities in the Water Adsorption and Morphology of Carbon Chars Assessed by NMR”

Coal and Char Studies by Advanced Emr Techniques

Water vapor adsorption on chars and active carbons–oxygen sensors prepared from a tropical tree wood

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