Centre d’Élaboration de Matériaux et d’Etudes Structurales (UPR 8011)


Accueil > Recherche > M3 : Matériaux Multi-échelles Multifonctionnels > Carbones nanostructurés > Propriétés, Mécanismes et Comportements des interactions

Nanoformes de carbone solide

Various interacting solid carbon nanoform systems are studied : C60-C60, C60 fullerenes versus so-called carbon "nanohorns", SWCNTs versus graphene surface.

  • C60-C60 (eventually compared with C70-C70) in the confined space of SWCNT inner cavities in order to investigate the coalescence mechanisms and subsequent transformation into DWCNTs as promoted by either temperature, or UV irradiation
  • C60 fullerenes versus so-called carbon "nanohorns", which revealed the role of the location of 5-rings with respect to the local curvature and that of oxygen bridges
  • SWCNTs versus graphene surface, which showed that energetics lead to differential adsorption of armchair versus zigzag SWCNT types, suggesting that tangential filtration on graphite surfaces could be a way to sort SWCNTs according to the various helicity types

Fullerene molecules adsorb onto single-graphene nano-objects (nanohorns) at the location of sharp-angle curvatures only (from (a) to (i)) whereas there is no fullerene adsorbed for large angle curvatures (from (j) to (m)). From (a) to (d) : 0° curvatures (6 pentagons in the graphene lattice). From (e) to (g) : 19° curvatures (5 pentagons) ; image (e) actually shows a 0° tip and a 19° cone superimposed. (h) and (i) : 30° curvatures (4 pentagons). (j) and (k) : 84° curvatures (3 pentagones). (l) and (m) : 113° curvatures (1 pentagon) ; image (m) shows three aligned examples of it ; other examples can be seen in (a) and (b) as well The cone angle value is not always equal to the ideal value because it may result from the projection of the tilted structure.

 

Individual carbon nanocones interacting with simple liquids allowed studying wetting phenomena at nanoscale upon collaboration with GNS Group at CEMES (T. Ondarçuhu - see the related comments in the GNS Group web pages).

On the other hand, we learn about bio-processes by – modestly - contributing to studies aiming to assess the positive or negative action of various kinds of CNTs on bio-systems upon collaboration with biologists seeking for physicists with a good expertise with carbon materials. Positive effects were found regarding the inhibition of microbial growth and calcium balancing in cells, but on the other hand cytotoxicity is observed due to perturbations brought to the electrochemistry-driven cell mechanisms.