CINaM - Centre Interdisciplinaire de Nanoscience de Marseille

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  • Campus de Luminy
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  • 13288 Marseille Cedex 9
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A venir ...

 
Jeudi 28 Septembre 2017
Fabien SILLY
TITANS, SPEC, CEA Saclay, CNRS, Université Paris-Saclay, 91191 Gif sur Yvette, France
Hierarchical engineering of 2D self-assembled porous organic-based nanoarchitectures on metal surfaces : on-surface synthesis of porous organic covalent-structures and self-assembled hybrid organic-ionic architectures
Engineering novel atomic and molecular nanostructures on surfaces is a challenge in nanosciences. We develop new process to engineer novel two-dimensional porous nanorachitectures based on molecular self-assembly on surfaces. PTCDI molecule self-assembled into compact domains on metal surfaces. We show that novel porous hybrid nanoarchitectures can bee engineered by mixing this molecule with ionic compounds. We fabricated three two-dimensional self-assembled hybrid PTCDI–NaCl nanoarchitectures, i.e. a flower-structure, a mesh-structure and a chain-structure on Au(111). Scanning tunneling microscopy (STM) reveals that NaCl-dimers selectively interact with molecular N–H groups. The PTCDI∙∙∙NaCl-dimer binding appears to be highly directional. Alternatively engineering two-dimensional (2D) covalent carbon-based nanoarchitectures has received tremendous attention during the resent years. We investigate on-surface bottom-up synthesis to create patterned graphene nanoarchitectures via Ullmann coupling. Star-shaped 1,3,5-Tris(4-iodophenyl)benzene molecules self-assemble into halogen-bonded structures on graphite [2]. In contrast, our STM measurements reveal that on-surface synthesis of covalent nanoarchitectures is competing with the growth of self-assembled halogen-bonded structures when this molecule is deposited on Au(111) in vacuum [3], Fig.2. We show that the molecules form covalent polygonal nanoachitectures at the gold surface step edges and at the elbows of the gold reconstruction at low coverage. With coverage increasing two-dimensional halogen-bonded structures appear and grow on the surface terraces. At high coverage the competitive growth between the covalent and halogen-bonded nanoarchitectures leads to formation of a two-layer film above one monolayer deposition. For this coverage, the covalent nanoarchitectures are propelled on top of the halogen-bonded first layer. References 1) J. Hieulle, D. Peyrot, Z. Jiang, F. Silly, Chem. Commun. 51, 13162 (2015) 2) F. Silly, J. Phys. Chem. C 117, 20244 (2013). 3) D. Peyrot, F. Silly, ACS Nano 10, 5490-5498 (2016).

Jeudi 12 Octobre 2017
Olivier Pouliquen
IUSTI, CNRS - Aix-Marseille Université
Ecoulement de milieux divisés: des milieux granulaires aux suspensions denses
Quiconque ayant joué avec le sable sur la plage ou du sucre dans la cuisine est conscient qu'une assemblée de grains rigides peut se comporter macroscopiquement comme un liquide et couler. La description de ce fluide singulier est un défi important pour de nombreuses applications industrielles (génie chimique, agroalimentaire, pharmaceutique,...) et dans beaucoup de situations géophysiques (écoulement de débris, avalanches, glissement de terrain,...). Dans ce séminaire, les avancées réalisées dans la compréhension de la rhéologie des écoulements granulaires et l'émergence d'une "hydrodynamique granulaire" seront présentées. Nous montrerons également comment cette approche s'est révélée pertinente pour aborder les problèmes de suspensions denses quand les grains sont plongés dans un liquide.

Jeudi 19 Octobre 2017
Pierre BUFFET
Faculté de Médecine Université Paris Descartes - Institut National de la Transfusion Sanguin