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Page personnelle de Marie-Louise Saboungi
Prof. Marie-Louise Saboungi,
Centre de Recherche sur la Matière Divisée
1B rue de la Férollerie
45071 Orléans Cedex 2 - France
Tel : +33-238-25-53-77
FAX :+33-238-63-37-96
Email MLS@cnrs-orleans.fr
Our current research areas cover a broad range of topics in the physics and chemistry of porous materials, nanoparticles and soft matter, including :
1. Functionalised nanotube composites
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We are developing fully integrated nanotube composite materials through the functionalization of multiwall carbon nanotubes (MWCNTs) by covalently attaching protein molecules to their surface. We have found a dramatic enhancement in the mechanical properties of the biocompatible thermoplastic polymer PVA with the addition of ferritin functionalized MWCNTs. The figure shows a TEM image of ferritin functionalized MWCNT-PVA composites, showing that the MWCNTs are nicely dispersed and attached to the PVA via ferritin molecules. |
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2. Synthesis and applications of mesoporous nanospheres
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Mesoporous nanospheres have many potential applications in biochemical separations, localized drug delivery and biotechnology. We are studying the effects of various parameters in the synthesis process on the morphology and texture of mesoporous silica spheres. The figure shows a TEM micrograph of uniform spherical nanospheres of MCM-41 prepared by a one-step synthesis in an all-water medium. Both the external organization and internal pore structure depend strongly on the surfactant concentration used. |
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3. Collective excitations in levitated liquids
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Experimental information about the dynamics of complex liquids is needed in order to establish universal mechanisms that govern the behaviour of liquids at the interface between purely hydrodynamic and kinetic regimes, where a rigorous theoretical description is lacking. To access high temperatures and avoid contamination of the sample by a container, we use aerodynamic levitation combined with laser heating to obtain a containerless environment. We can then study the nm-scale dynamics with inelastic x-ray scattering (IXS). We also take advantage of the levitation technique to access the deeply supercooled liquid state. |
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4. Hydrogen confinement in carbon nanomaterials
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Carbon nanostructures have attracted considerable attention as hydrogen storage materials ever since their discovery. While significant amounts of hydrogen can be absorbed in single-walled nanotubes by pressurizing and cooling, almost all of it escapes when the material is brought up to ambient temperature. Single-walled carbon nanohorns graphitic structures (see Figure) with a dahlia-like shape formed by aggregation of nanotubular structures, appear more promising since the adsorption process appears to be reversible and most of the hydrogen released at ambient temperature is readsorbed when the temperature is lowered again |
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5. Absorption of semiconductors in zeolites
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Semiconducting quantum dots and quantum wires are being developed for a wide variety of applications including optoelectronics, photocatalysis and solar energy conversion. To be practically useful, they must be organized into ordered 2-D and 3-D arrays with a high degree of monodispersion, regular spacing between particles and stability against environmental degradation. Encapsulation in zeolites would appear to meet all the requirements listed above and in addition provide a range of cage and channel sizes ideal for quantum confinement. Furthermore, cation exchange in the zeolite hosts presents an additional handle for modifying the electronic properties of the encapsulated semiconductor. |
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6. Nanocomposite polymer electrolytes
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The structure and dynamics of polymers in a confined environment is important for furthering our understanding and control of the glass transition and melting, which are closely coupled to transport properties in these systems. Moreover, in the field of solid-state lithium batteries, transfer phenomena at the polymer/electrode interface are often factors limiting either fluxes or lifetimes. We have synthesized novel hybrid materials consisting of poly(ethylene oxide) (PEO) confined in hydrated titanium oxide nanotubes. We are also studying PEO and PEO-based electrolytes confined in synthetic clays and porous silicas. |
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7. Structure and dynamics of saccharide solutions
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The disaccharide trehalose is produced in large quantities under conditions of water stress in a number of cold- and drought-adapted organisms. A particular example is the Rose of Jericho (shown opposite), which looks quite dead after dehydration but can recover fully with the first traces of water. The presence of trehalose in these organisms is known to be responsible for their desiccation tolerance, but the mechanisms of its activity are not understood. We are studying the microscopic dynamics of trehalose and other saccharides to help explain these remarkable phenomena. |
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8. Magnetoresistance in non-magnetic compounds
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The silver chalcogenides are non-magnetic materials, but their electrical resistance can be made very sensitive to magnetic field by adding small amounts—just 1 part in 104—of excess silver. The resistance of Ag2Se displays a large, nearly linear increase with applied magnetic field without saturation to the highest fields available, 60 T, more than a million times the Earth’s magnetic field. (The figure shows the behaviour up to 6T). These characteristics make the silver chalcogenides attractive as magnetic-field sensors. High-field studies at low temperatures reveal both oscillations in the magnetoresistance and a universal scaling form that point to a quantum origin for this unprecendented behaviour. |
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Selected Recent Publications (numbers in parentheses refer to topics above)
Polymer Composites with Protein Functionalized Carbon Nanotubes, S. Bhattacharyya, J.-P. Salvetat, M-L. Saboungi, Accepted in Journal of Bio-medical Materials and Engineering. (1)
Protein Functionalized Carbon Nanotubes, S. Bhattacharyya, C. Sinturel, J-P Salvetat, M-L Saboungi, Applied Physics Letters, 86, 113104, 2005. (Cover page article ; .a selected for the March 15, 2005 issue of Virtual Journal of Biological Physics Research). (1)
Reinforcement of Semicrystalline Polymers with Collagen-Modified Single Walled Carbon Nanotubes S. Bhattacharyya, J-P Salvetat, M-L Saboungi, Applied Physics Letters 88, 233119 -233121, 2006. (1)
Recent Progress intThe Synthesis and Selected Applications of MCM-41 - A Short Review, S. Bhattacharyya, G. Lelong, M.-L. Saboungi , Journal of Experimental Nanoscience 2006, in press. (2)
Collective Excitations in an Early Molten Transition Metal A. H. Said, H. Sinn, A. Alatas, C. Burns, D. L. Price, M. L. Saboungi, W. Schirmacher, Physical Review (B), short report, 74, 172202 (2006). (3)
Microscopic Dynamics of Liquid Aluminium Oxide, H. Sinn, B. Glorieux, L. Hennet, A. Alatas, E. E. Alp, F. J. Bermejo, D. L. Price, M.-L. Saboungi , Science, 299, 2047-2049, 2003. (3)
Dynamical Aspects of Disorder in Condensed Matter, D.L. Price, M-L Saboungi, J. Bermejo, Reports on Progress in Physics, 66 : 407-480, 2003. (3)
Collective Excitations in Liquid D2 Confined within the Mesoscopic Pores of an MCM-41 Molecular Sieve, C. Mondelli, M. A. González, F. Albergamo, C. Carbajo, M. J. Torralvo, E. Enciso ,F. J. Bermejo, R. Fernández-Perea,C. Cabrillo,V. Leon, M. L. Saboungi, Physical Review B 73, 1098-0121, 2006. (4)
Selenium/Zeolite Y Nanocomposites : Structure, Electronic Properties and Stability, A. Goldbach, M-L Saboungi, Accounts of Chemical Research, 38 (9), 705 -712, 2005. (5)
An Air-Stable Selenium/Zeolite Nanocomposite, A. Goldbach, L. E. Iton, M. Grimsditch, M-L Saboungi, Chemistry of Materials, 16, 5107-5113, 2004. (5)
Threading Polymer into Nanotubes : Evidence of Poly(ethylene oxide) Inclusion in Titanium Oxide, M. Volel, M. Armand, W. Gorecki, M-L Saboungi, Chemistry of Materials, 17, 2028-2033, 2005. (6)
A Unified Approach to the Dynamics of a Polymer Melt J-M Zanotti, L. J. Smith, D. L. Price, M-L Saboungi, Journal of Physics Condensed Matter, 18 (2006) S2391–S2402. (6)
Molecular Dynamics of Confined Glucose Solutions, G. Lelong, D. L. Price, A. Douy, S. Kline, J. W. Brady and M-L Saboungi, Journal of Chemical Physics 122, 164504, 2005(also in Virtual Journal of Biophysical Research, May 1, 2005). (7)
Dynamics of Water Molecules in Glucose Solutions, C. Talon, L. J. Smith, J. W. Brady, B. A. Lewis, J. R. D. Copley, D. L. Price, M-L Saboungi, Journal of Physical Chemistry B., 108, 5120-5126, 2004. (7)
Diffusion Rates of Glucose in Solution via Quasielastic Neutron Scattering, L. J. Smith, J.W. Brady, Z. Chowdhuri, D. L. Price, M.-L. Saboungi, Journal of Chemical Physics (Letter) 120, 3527-3530, 2004 (also in Virtual Journal of Biophysical Research, March 1, 2004). (7)
Megagauss Sensors, A. Husmann, J. B. Betts, G.S. Boebinger, A. Migliori, T. F. Rosenbaum and M.-L. Saboungi, Nature 417, 421-425, 2002. (8)
Band Gap Tuning and Linear Magnetoresistance in the Silver Chalcogenides, M. Lee, T.F. Rosenbaum, M.-L. Saboungi, and H.S. Schnyders, Physical Review Letters, 88, 066602, 2002. (8)
Patents
Matériau composite constitué par une matrice poreuse et des nanoparticules de métal ou d’oxyde de métal" , R. Benoit, M. Treguer-Delapierre, M-L Saboungi, CNRS – Patent Accepted September 2004.
Method for Synthesizing Extremely High-Temperature Melting Materials, M-L Saboungi, B. Glorieux, US 6,967,011B1 ; issued 22/11/2005
Large Magnetoresistance in Non-Magnetic Silver Chalcogenides and New Class of Magnetoresistive Compounds, S-88007, M-L Saboungi, D. L. Price, T. F. Rosenbaum, R. Xu, A. Husmann,US 6,316,131B1 ; issued 13/11/2001
