Université de Neuchâtel

Microactuators based on ion implanted dielectric electroactive polymer (EAP) membranes

Dubois, Philippe ; Rosset, Samuel ; Koster, Sander ; Stauffer, Johann ; Mikhaïlov, Serguei ; Dadras, Massoud ; de Rooij, Nicolaas F. ; Shea, Herbert

In: Sensors and Actuators A: Physical, 2006, vol. 130-131, p. 147-154

We report on the first successfully microfabricated and tested ion implanted dielectric electroactive polymer (DEAP) actuators. Dielectric EAP (DEAP) actuators combine exceptionally high energy–density with large amplitude displacements [S. Ashley, Artificial muscles, Sci. Am. 289 (2003) 52–59; R. Pelrine, R. Kornbluh, J. Joseph, R. Heydt, Q. Pei, S. Chiba, High field deformation of...

Université de Neuchâtel

Evidence for an organic origin of pedogenic calcitic nanofibres

Dadras, Massoud ; Abolhassani-Dadras, Sousan ; Braissant, Olivier ; Verrecchia, Eric P.

In: Journal of Crystal Growth, 2009, vol. 311, no. 8, p. 2490-2495

Calcium carbonate nanofibres are found in numerous terrestrial environments, often associated with needle fibre calcite. This study attempts to mimic the natural system and generate comparable crystalline structures. A comparison of natural and synthesized nanofibre structures, using HRTEM as well as electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI), has...

Université de Neuchâtel

Ruthenium Nanoparticles Intercalated in Hectorite: A Reusable Hydrogenation Catalyst for Benzene and Toluene

Süss-Fink, Georg ; Mollwitz, Birgit ; Therrien, Bruno ; Dadras, Massoud ; Laurenczy, Gabor ; Meister, Annette ; Meister, Götz

In: Journal of Cluster Science, 2007, vol. 18, no. 1, p. 87-95

The cationic organometallic aqua complexes formed by hydrolysis of [(C6H6)RuCl2]2 in water, mainly [(C6H6)Ru(H2O)3]2+, intercalate into sodium hectorite by ion exchange, replacing the sodium cations between the anionic silicate layers. The yellow hectorite thus obtained reacts in ethanol with...

Université de Fribourg

Controlling the lateral aggregation of perfluoroalkylated hexa-peri-hexabenzocoronenes

Aebischer, Olivier F. ; Aebischer, Annina ; Donnio, Bertrand ; Alameddine, Bassam ; Dadras, Massoud ; Güdel, Hans-Ulrich ; Guillon, Daniel ; Jenny, Titus A.

The investigation of two hexa-peri-hexabenzocoronene (HBC) derivatives carrying linear or branched perfluoroalkylated side chains is reported. Polycondensed aromatic hydrocarbons (PAH) such as HBC derivatives are well known to self-organize to form highly ordered monomolecular stacks, which in turn show a concentration- and solvent-dependent lateral aggregation. However, possible...

Université de Fribourg

Self-aggregated perfluoroalkylated hexa-peri-hexabenzocoronene fibers observed by cryo-SEM and fluorescence spectroscopy

Aebischer, Olivier F. ; Aebischer, Annina ; Tondo, Patrick ; Alameddine, Bassam ; Dadras, Massoud ; Güdel, Hans-Ulrich ; Jenny, Titus A.

In: Chemical Communications, 2006, p. 4221 - 4223

The self-assembled architectures in solution of a new HBC derivative bearing perfluoroalkylated side chains were investigated by optical excitation and emission spectroscopy and correlated to cryo-SEM, a new technique in organic chemistry.

Université de Neuchâtel

Supramolecular cluster catalysis : facts and problems

Süss-Fink, Georg ; Therrien, Bruno ; Vieille-Petit, Ludovic ; Tschan, Mathieu J.-L. ; Romakh, Vladimir B. ; Ward, Thomas R. ; Dadras, Massoud ; Laurenczy, Gabor

In: Journal of Organometallic Chemistry, 2004, vol. 689, p. 1362-1369

By checking the chemistry underlying the concept of "supramolecular cluster catalysis" we identified two major errors in our publications related to this topic, which are essentially due to contamination problems. (1) The conversion of the "closed" cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) into the...