Laboratoire d’analyse et d’architecture des systèmes
Rapport LAAS N°18410, Décembre 2018
Rapport de Contrat : Contrat CNRS 181596, Novembre 2018, 7p. , N° 18386
G.LAHINER, JA.ZAPATA CORREA, M.DJAFARI ROUHANI, A.ESTEVE, C.ROSSI
Rapport LAAS N°18405, Novembre 2018
T.CALAIS, A.BANCAUD, A.ESTEVE, C.ROSSI
Revue Scientifique : ACS Applied Nano Materials, Vol.1, N°9, pp.4716-4725, Septembre 2018 , N° 18279
The association of a metallic fuel (usually aluminum) with an oxidizer (metal oxide or organic compound) creates an exothermic material that can be ignited with an external stimulus such as local heating or spark discharge. These materials with high energetic performances, called nanothermites, have been used to release temperature or pressure waves for civil or military applications (initiators, impact igniters, etc.). However, the energetic performances of these nanothermites are highly dependent on the nanoscale intimacy of the two components. The use of nanoparticles results in an increase of the energy release, but control of their assembly remains particularly challenging. In this work, we demonstrate that the use of DNA to self-organize Al or CuO nanoparticles greatly enhances the energy release of nanothermites by up to 240% compared to classically sonicated nanothermites in hexane, with the heat of reaction prior to Al melting reaching a value of 2.57 kJ·g–1. In particular, we report that the energetic performances can be tuned by controlling the ionic strength during the self-assembly process. These results are supported by ultrafine characterization of the nanocomposite microstructure based on high-resolution transmission electronic microscopy and energy-dispersive X-ray spectroscopy. Besides, we report the surprisingly good energetic performances of randomly mixed nanoparticles dispersed in water, nonetheless 40% lower than DNA-self-assembled nanocomposites. Altogether, our study not only proposes an easy and immediate process for nanocomposites synthesis but also opens the door for opportunities toward large-scale crystalline Al–CuO superlattices with high energetic performances.
Y.GAO, M.IACHELLA, E.C.MATTSON, A.LUCERO, J.KIM, M.DJAFARI ROUHANI, Y.J.CHABAL, C.ROSSI, A.ESTEVE
NEO, University of Texas
Revue Scientifique : Journal of Physical Chemistry C, Vol.122, N°31, pp.17856-17864, Août 2018, DOI: 10.1021/acs.jpcc.8b04952 , N° 18193
Deposition of Al onto ZnO surfaces is important for metal/insulator contacts in microelectronics and photovoltaic devices, and also for nano-energetic materials; yet there have not been fundamental studies of these interfaces, in particular those involving the polar faces of ZnO. Density Functional calculations and Low Energy Ion Scattering (LEIS) studies are combined to unravel the chemistry of Al interaction on polar ZnO surfaces, revealing that Al atoms quasi spontaneously replace surface Zn atoms on both O-and Zn-terminated ZnO surfaces. In this process, aluminum atoms attract oxygen atoms, releasing zinc atoms through electrostatic repulsion within the growing alumina film. Kinetics and thermodynamics calculations indicate that zinc atoms accumulate on the surface rather than migrating into ZnO bulk at room temperature, due to high bulk diffusion barriers. Upon annealing to moderate temperatures, LEIS studies indicate that surface Zn atoms desorb at ~ 140-150 °C, which is consistent with the calculated 1.31 eV activation barrier.
J.CURE, H.ASSI, K.COCQ, L.MARIN MERCADO, K.FAJERWERG, P.FAU, E.BECHE, Y.J.CHABAL, A.ESTEVE, C.ROSSI
NEO, LCC, PROMES, University of Texas
Manifestation avec acte : Gold ( Gold ) 2018 du 15 juillet au 18 juillet 2018, Paris (France), Juillet 2018, 1p. , N° 18340
Since Faraday in the 1850s, gold nanoparticles (AuN Ps) have been th e subject of growing interest. AuNPs are now commonly us ed in many applications such as such as sensors, photocatalysis, photovoltaic devices, and biological labeling. The deposition of gold nanoparticles ( Au NPs) on zinc oxide films a key step for (photocatalysis)catalysis or photovoltaic applications, still remains difficult to master.
J-M.POUCHAIRET-RAMONA, A.BELISARIO, A.NICOLLET, D.MEDUS, C.ROSSI
NEO, Etienne Lacroix
Manifestation avec acte : International Pyrotechnics Society Seminar ( IPSUSA ) 2018 du 08 juillet au 13 juillet 2018, Fort Collins (USA), Juillet 2018, 5p. , N° 18224
In the midst of a growing need for standardisation and adaptability in pyrotechnic systems, we hereby present a safe pyrotechnical infrared (IR) flare electronically controllable through an embedded miniature initiation system. The countermeasure consists of three distinct blocks: (1) a controllable pyrotechnical ejection block, made of three independently addressable small - scale ejectors integrated in a one - piece molded interconnected device , (2 ) a terminal stage comprising a structured IR pyrotechnical loaf coupled with a micro - initiation stage integrating low - energy on - chip addressable nanothermite - based initiators , and (3 ) a connected, autonomous, STANAG 4187 compliant, electronic sensors, arming and firing block
Revue Scientifique : Propellants, Explosive, Pyrotechnics, Juillet 2018 , N° 18028
Sputter-deposited Al/CuO multilayers represent the state-of-the-art of energetic nanomaterials. As such, they offer an opportunity for tunable ignition and actuation because their theoretical energy densities are significantly higher than most conventional secondary explosives while being less sensitive to undesired initiation. Both the sensitivity and combustion properties (temperature, rate and products released) can be manipulated via the layering, reactant spacing and stoichiometry of the multilayer and, to a lesser extent, via interface engineering. In this article, we first describe the technology of deposition of Al/CuO multilayers focusing on direct current sputter deposition followed by a comprehensive review of the materials structural characteristics. Next, experimental and theoretical works performed on these reactive multilayered materials to date is presented in terms of methods used, the results acquired on ignition and combustion properties, and conclusions drawn. Emphasis is placed on several studies elucidating the fundamental processes that underlie propagating combustion reactions. We examine the influence of the « ceiling » temperature that traduces the multilayer disintegration when reaching high temperatures (e.g., vaporization temperatures). This paper provides a good support for engineers to safely propose Al/CuO multilayers structure to regulate the energy release rates and ignition threshold in order to manufacture high performance and tunable initiator devices.
Manifestation avec acte : GRC: Energetic Materials ( ) 2018 du 03 juin au 08 juin 2018, Newry (USA), Juin 2018, 2p. , N° 18157
P.CHAMPIGNEUX, C.RENAULT-SENTENAC, D.BOURRIER, C.ROSSI, M.L.DELIA, A.BERGEL
LGC, NEO, TEAM
Revue Scientifique : Bioelectrochemistry, Vol.121, pp.191-200, Juin 2018 , N° 18045