Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
ISSN: 0043-1648

hal-01679411
https://hal.univ-antilles.fr/hal-01679411
DOI : 10.1016/j.wear.2004.11.019

Éditeur(s) : HAL CCSD
Résumé : International audience
Society of tribologist and lubrication Engineers annual Meeting and exhib
Las vegas, United States

hal-01682115
https://hal.univ-antilles.fr/hal-01682115

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The structural parameters of fluorinated nanocarbons presenting different shapes, i.e. spherical, tubular and discotic are investigated and correlated to their tribological properties. Different fluorination rates of graphitized carbon blacks (0D), carbon nanofibres (1D) and a mixture of carbon nanodiscs and nanocones (2D) were achieved under pure molecular fluorine gas flow (direct fluorination). Raman spectrometry, X-ray diffraction and 19F solid state nuclear magnetic resonance underline similar structure and nature of the C-F bonds (covalent) for equivalent fluorine contents. In spite of the similarities of physical-chemical properties at equivalent fluorine contents, the tribological properties of the fluorinated nanocarbons differ. Those properties are discussed taking into account the role of the fluorine content and location of the fluorine atoms in the decrease of the interparticle interactions and in the cleavage of the external fluorocarbon layers to form the tribofilm. Finally, the effect of the shape is discussed.
ISSN: 0022-1139

hal-00787267
https://hal.archives-ouvertes.fr/hal-00787267

Éditeur(s) : HAL CCSD
Résumé : International audience
In boundary lubrication regime, friction reduction and antiwear processes are associated to the presence of additives in the lubricating oils or greases. These processes are due to the formation of protective tribofilms resulting from chemical reactions between the additives and the sliding surfaces, in the physico-chemical conditions of the sliding contact. Conventional antiwear additives mainly consist of transition metal organo phosphate or thiophosphates which present a remarkable efficiency in the case of contacts between ferrous alloys. In the case of non reacting surfaces, these additives become inactive. Recently developped lubrication strategies consist in the use of dispersion in oils of nano additives able to build the protective tribofilm in the sliding contact without reaction with the surfaces. Carbon fluorinated phases, due to their lamellar structure and their high chemical stability even at relatively high temperature (400°C) represent interesting candidates as lubricant nano-additives subjected to present friction reduction, anti wear and anti corrosion actions. This work presents the tribologic behaviour of some carbon fluorinated derivatives such as graphite fluorides, fluorinated carbon nanofibers, fluorinated carbon nanodiscs and fluorinated carbon blacks. The influence, on the tribologic performances, of the structure of the initial carbon phases, of the fluorination rate (0
World Tribology Congress 2013
Torino, Italy

Droits : info:eu-repo/semantics/OpenAccess
hal-00926514
https://hal.archives-ouvertes.fr/hal-00926514
https://hal.archives-ouvertes.fr/hal-00926514/document
https://hal.archives-ouvertes.fr/hal-00926514/file/Delbe_9783.pdf
OATAO : 9783

Éditeur(s) : HAL CCSD Cambridge University Press (CUP)
Résumé : International audience
ISSN: 1431-9276

hal-01680427
https://hal.univ-antilles.fr/hal-01680427
DOI : 10.1017/S1431927614010654

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Resistance to artemisinin casts a shadow on the fight against malaria. The importance of illegal gold miners and of malaria in isolated regions of French Guiana constitutes a threat that endangers the fight against malaria in the Amazon. The hurdles of French laws and the remoteness of the territory from France make it impossible for the system to adapt to the problem of total inaccessibility of an important part of the malaria problem. Transmission is high in these areas and gold miners self-medicate with erratic regimens of artemisinin combinations, thus creating perfect conditions for the emergence of resistance. What needs to be done is being done, but within the limits of national law, with some results. However, facing the same difficult problem, Suriname shows more flexibility and is doing much better than French Guiana despite having lower resources. Local authorities in French Guiana cannot overrule the laws that block appropriate malaria care from reaching a third of malaria-exposed persons. Thus the health authorities in France should take immediate calibrated legislative and financial measures to avoid a predictable disaster.
ISSN: 1475-2875

inserm-00838961
http://www.hal.inserm.fr/inserm-00838961
http://www.hal.inserm.fr/inserm-00838961/document
http://www.hal.inserm.fr/inserm-00838961/file/Nacher_et_al._Malaria_J.pdf
PUBMED : 23641802

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
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 re-building of graphitic domains in the case of perfluorinated compounds which explains the improvement of μ during the friction tests for these last materials.
ISSN: 1023-8883

hal-00767637
https://hal.archives-ouvertes.fr/hal-00767637
https://hal.archives-ouvertes.fr/hal-00767637/document
https://hal.archives-ouvertes.fr/hal-00767637/file/Delbe_6329.pdf
DOI : 10.1007/s11249-009-9487-6

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The present work is concerned with the study of the tribological properties of various fluorinated carbon phases obtained at room temperature and then post-treated under fluorine atmosphere at different temperatures. The tribological tests evidence good intrinsic properties for all the compounds (friction coefficient in the range 0.07-0.09). Differences appear after few cycles. Friction measurements after 100 cycles and complementary Raman analyses of the tribofilm remaining in the wear scar point out that long term tribologic properties of the fluorinated compounds strongly depend on the evolution undergone by the materials under friction. The release of HF molecules, the loss of fluorine and partial rebuilding of graphitic phases are at the origin of the degradation of the friction properties. The good properties of the compounds post-treated at temperature in the range 150-300 °C are attributed to the chemical and structural stability of these compounds under friction.
ISSN: 0022-3697

hal-00756133
https://hal.archives-ouvertes.fr/hal-00756133
https://hal.archives-ouvertes.fr/hal-00756133/document
https://hal.archives-ouvertes.fr/hal-00756133/file/Delbe_6346.pdf
DOI : 10.1016/j.jpcs.2006.01.084