NMR and EPR studies of room temperature highly fluorinated graphite heat-treated under fluorine atmosphere

Dubois, Marc; Guérin, Katia; Pinheiro, José Paulo; Fawal, Ziad; Masin, Francis; Hamwi, A.

doi:10.1016/j.carbon.2004.03.025

Cited by 87 publications

(118 citation statements)

References 17 publications

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“…The peak near 40 ppm is related to non-fluorinated sp 3 carbon atoms (C sp3 ) as in the case of (C 2 F) n [17]. The third large resonance peak centred near 120 ppm is mainly assigned not only to non-fluorinated sp 2 carbon atoms but also to carbon atoms in weak interaction with fluorine (semi-ionic C-F bonds at d * 140 ppm) [8], respectively, noted C graphitic and C-F. The graphitic carbon atoms fraction (c) present in the sample can be estimated by the ratio of the area of the C graphitic peak over the sum of the areas of all the peaks (C-F ?…”

Section: Structure Of Fluorinated Carbon Nanofibresmentioning

confidence: 96%

“…Recently, graphite fluorides were obtained at room temperature by reaction of graphite with gaseous fluorine in the presence of HF and volatile fluoride MF n (IF 5 , BF 3 ) as catalysts [7][8][9]. In these materials, the nature of the C-F bond evolves from semi-ionic (sp 2 hybridization of carbon atoms) to covalent (sp 3 hybridization of carbon atoms) depending on the synthesis conditions.…”

Section: Introductionmentioning

confidence: 99%

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Tribological Properties of Fluorinated Carbon Nanofibres

Pandorf¹,

Himmel²,

Mansot³

et al. 2009

Tribol Lett

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This work is concerned with the study of the tribological properties of fluorinated carbon nanofibres with various fluorination rates. The tribological tests, carried out in the presence of pentane and in air after liquid's evaporation demonstrate good friction properties for all the compounds (the friction coefficients ranging between 0.04 and 0.06 in the presence of pentane and between 0.07 and 0.09 in air). Raman analyses reveal that the friction process induces a partial deterioration of the carbon fibres and SEM studies show that the tribofilm is composed of individual fibres embedded in a more disordered carbonaceous matrix. The fibrous nature of the tribofilm and the experimental relationship between friction coefficient and fluorination rate strongly support that friction properties of fluorinated carbon nanofibres are governed by surface fibres interaction. The modification of the nanofibres surface tension by action of pentane or optimum fluorination rate leads to a lowering of interfibres interactions resulting in an improvement of the friction properties.

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Section: Structure Of Fluorinated Carbon Nanofibresmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Tribological Properties of Fluorinated Carbon Nanofibres

Pandorf¹,

Himmel²,

Mansot³

et al. 2009

Tribol Lett

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“…The fluorine compounds (ClF 3 , BrF 3 , LiF, etc.) in molten salts can react with graphite [5][6][7][8], and the pores in the nuclear graphite can accommodate the molten salt and fission products in normal operation condition [9]. Therefore, it is important to systematically analyze the pore structure characteristics of nuclear graphite in three-dimensional spaces.…”

Section: Introductionmentioning

confidence: 99%

3D microstructures of nuclear graphite: IG-110, NBG-18 and NG-CT-10

Jing

Zhang

et al. 2016

NUCL SCI TECH

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Molten salt is used as primary coolant flowing through graphite moderator channel of a molten salt reactor. Working at high temperature under radiation environment, the pore network structure of nuclear graphite should be well understood. In this paper, X-ray tomography is employed to study the 3D pore structure characteristics of nuclear grades graphite of IG-110, NBG-18 and NG-CT-10, and permeability simulation through geometries are performed. The porosity, number of pores and throats, coordination number and pore surface are obtained. NG-CT-10 is of similar microstructure to IG-110, but differs significantly from NBG-18. The absolute permeabilities of IG-110, NG-CT-10 and NBG-18 are 0.064, 0.090 and 0.106 mD, respectively. This study provides basis for future research on graphite infiltration experiment.

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“…Recently, graphite fluorides obtained at room temperature by the reaction of graphite with gaseous F 2 , HF, and MF n mixture (the volatile fluorides MF n used were IF 5 , BF 3 , and ClF 3 ) have been treated under fluorine at temperatures between 100 and 600°C [11][12][13][14][15]. The coexistence of sp 2 and sp 3 carbon atoms confers to these materials interesting electrochemical properties for primary lithium batteries [16].…”

Section: Introductionmentioning

confidence: 99%

Tribological Properties of Room Temperature Fluorinated Graphite Heat-Treated Under Fluorine Atmosphere

Delbé¹,

Pandorf²,

Himmel³

et al. 2009

Tribol Lett

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This work is concerned with the study of the tribologic properties of room temperature fluorinated graphite heat-treated under fluorine atmosphere. The fluorinated compounds all present good intrinsic friction properties (friction coefficient in the range 0.05-0.09). The tribologic performances are optimized if the materials present remaining graphitic domains (influenced by the presence of intercalated fluorinated species) whereas the perfluorinated compounds, where the fluorocarbon layers are corrugated (armchair configuration of the saturated carbon rings) present higher friction coefficients. Raman analyses reveal that the friction process induces severe changes in the materials structure especially the partial rebuilding of graphitic domains in the case of perfluorinated compounds which explains the improvement of l during the friction tests for these last materials.

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NMR and EPR studies of room temperature highly fluorinated graphite heat-treated under fluorine atmosphere

Cited by 87 publications

References 17 publications

Tribological Properties of Fluorinated Carbon Nanofibres

Tribological Properties of Fluorinated Carbon Nanofibres

3D microstructures of nuclear graphite: IG-110, NBG-18 and NG-CT-10

Tribological Properties of Room Temperature Fluorinated Graphite Heat-Treated Under Fluorine Atmosphere

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