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237 results on '"Laboratoire de Spectrométrie Physique (LSP)"'

1. Enhancement of Two-Photon Absorption via Oligomerization. A Route for the Engineering of Two-Photon Absorbers in the Visible Range

Author

Patrice L. Baldeck, Rémy Fortrie, Henry Chermette, Olivier Stéphan, Rémi Anémian, and Chantal Andraud, Jean-Christophe Mulatier, Laboratoire de Chimie - UMR5182 ( LC ), École normale supérieure - Lyon ( ENS Lyon ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Spectrométrie Physique ( LSP ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ), Sciences Analytiques ( SA ), Université Claude Bernard Lyon 1 ( UCBL ), Laboratoire de Chimie - UMR5182 (LC), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Sciences Analytiques (SA), Université Claude Bernard Lyon 1 (UCBL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)

Subjects
Materials science, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Molecular physics, Two-photon absorption, Organic molecules, Two-photon excitation microscopy, [ CHIM.ORGA ] Chemical Sciences/Organic chemistry, Molecule, Physical and Theoretical Chemistry, Absorption (electromagnetic radiation), Coupling, business.industry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Charge (physics), [ CHIM.INOR ] Chemical Sciences/Inorganic chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, General Energy, [ CHIM.MATE ] Chemical Sciences/Material chemistry, Visible range, Optoelectronics, 0210 nano-technology, business
Abstract

International audience; In this paper, we develop a new strategy for designing organic molecules exhibiting at the same time a strong two-photon absorption and a good transparency in the visible region: the oligomeric strategy. At the present time, these two properties are hardly simultaneously fulfilled only by a few existing organic molecules. This approach does not involve any charge transfer and then contrasts with the donor−acceptor strategy. The one- and two-photon absorption properties of 9,9-dihexylfluorene oligomers are first presented and then analyzed thanks to a simple three-level excitonic coupling model. This model, which succeeds in reproducing the experimental data, is then used as a prospective tool, and a set of simple rules is extracted for improving the optical properties of this family of molecules.

Published
2007

2. Organometallic precursors as catalyst to grow three dimensional micro/nano structures: spheres, clusters and wires

Author

J.C. Vial, M. J. S. P. Brasil, P. Cheyssac, Th. Chiaramonte, F. Donatini, Jean Decobert, Marco A. Sacilotti, Fernando Iikawa, M. K. K. Nakaema, Gilles Patriarche, Marina Fuser Pillis, Lisandro Pavie Cardoso, Y. Lacroute, Laboratoire de Physique de l'Université de Bourgogne ( LPUB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de physique de la matière condensée ( LPMC ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Photonique et Nanostructure, CNRS, Route de Nozay, 91460 Marcoussis, France, Laboratoire Matériaux Optiques, Photonique et Systèmes ( LMOPS ), CentraleSupélec-Université de Lorraine ( UL ), LDRX & GPO ( IFGW INICAMP ), L. Optica-Unicamp-Campinas, Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Laboratoire de Spectrométrie Physique ( LSP ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Recherche sur les capteurs à colloides et l'instrumentation ( LRCCI ), Université Jean Monnet [Saint-Étienne] ( UJM ), Laboratoire de Physique de l'Université de Bourgogne (LPUB), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de la matière condensée (LPMC), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Matériaux Optiques, Photonique et Systèmes (LMOPS), CentraleSupélec-Université de Lorraine (UL), LDRX & GPO (IFGW INICAMP), Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Recherche sur les capteurs à colloides et l'instrumentation (LRCCI), and Université Jean Monnet [Saint-Étienne] (UJM)

Subjects
Materials science, Nanostructure, Trimethyl-gallium, Alloy, Nanowire, Oxide, [ PHYS.COND.CM-MS ] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Nanotechnology, 02 engineering and technology, Substrate (electronics), engineering.material, 01 natural sciences, Metal, chemistry.chemical_compound, 0103 physical sciences, Materials Chemistry, Metalorganic vapour phase epitaxy, 010302 applied physics, Surfaces and Interfaces, General Chemistry, Nanostructured materials, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, Nanocrystals, Chemical engineering, chemistry, Nanocrystal, visual_art, MOCVD, visual_art.visual_art_medium, engineering, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology
Abstract

This paper presents the growth and characterization of three-dimensional structures using metal-organic (or organometallic) chemical precursors like M(CH 3 ) 3 , where M is a metal. Their morphology depends principally on growth temperature and conditions at the surface of the substrate. These 3D structures can be separated into two classes: i) one with (Ga, Al, In) metallic alloys shaped as sphere, sceptre or cylinder and a carbon membrane covering the alloy; ii) the other with semiconductor or oxide nanowires capped by a metallic sphere. The metal-organic precursors can be seen as catalysts molecules that grow semiconductors with micro and nanostructures similar to the role of gold particles used to grow nanowires in the VLS mechanism. We present the MOCVD growth of Ga 2 O 3 , CuGa x O y and (Ga,In)P nanowires using the metal-organic precursors on metallic or metal containing substrates.

Published
2007

3. Up-conversion emission in rare earth-doped Y2Ti2O7 sol-gel thin films

Author

G. Boccardi, P. Jenouvrier, Jochen Fick, A.-M. Jurdyc, Michel Langlet, Laboratoire des matériaux et du génie physique ( LMGP ), Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut polytechnique de Grenoble - Grenoble Institute of Technology ( Grenoble INP ), Institut de Microélectronique, Electromagnétisme et Photonique ( IMEP ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National Polytechnique de Grenoble ( INPG ) -Centre National de la Recherche Scientifique ( CNRS ), CP, Laboratoire de Spectrométrie Physique ( LSP ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physico-Chimie des Matériaux Luminescents ( LPCML ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire des matériaux et du génie physique (LMGP ), Institut National Polytechnique de Grenoble (INPG)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Microélectronique, Electromagnétisme et Photonique (IMEP), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physico-Chimie des Matériaux Luminescents (LPCML), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon

Subjects
Ytterbium, Materials science, Inorganic chemistry, Biophysics, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, Biochemistry, Erbium, 0103 physical sciences, Thin film, ComputingMilieux_MISCELLANEOUS, Sol-gel, [PHYS]Physics [physics], 010302 applied physics, Doping, General Chemistry, Yttrium, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Titanate, Thulium, chemistry, 0210 nano-technology
Abstract

Yttrium titanate (YTO) thin films doped with rare earth elements have been deposited using the aerosol–gel process. The up-conversion emission (UPE) of films doped with erbium and/or thulium has been studied with respect to the film crystallization degree and rare earth concentration. The effects of ytterbium codoping have been considered as well. Mechanisms that control UPE of YTO films are discussed with respect to the experimental conditions. It is shown that films, which selectively emit in the blue (1G4→3H6 transition of thulium ions), green (2H11/2→4I15/2 and 4S3/2→4I15/2 transitions of erbium ions), or red (4F9/2→4I15/2 transition of erbium ions), can readily be achieved.

Published
2005

4. Improvement in the luminescence properties of Si/CaF2 nanostructures

Author

Sandie Ménard, I. Mihalcescu, Franck Bassani, F. Arnaud d’Avitaya, Isabelle Berbezier, Laboratoire des technologies de la microélectronique ( LTM ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Physique Nucléaire d'Orsay ( IPNO ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence ( IM2NP ), Aix Marseille Université ( AMU ) -Université de Toulon ( UTLN ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Spectrométrie Physique ( LSP ), Laboratoire des technologies de la microélectronique (LTM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Photoluminescence, Silicon, Mineralogy, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, 0103 physical sciences, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, Quantum well, ComputingMilieux_MISCELLANEOUS, business.industry, Mechanical Engineering, Heterojunction, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Nanocrystalline material, chemistry, Mechanics of Materials, Optoelectronics, Quantum efficiency, 0210 nano-technology, Luminescence, business, [ PHYS.COND ] Physics [physics]/Condensed Matter [cond-mat], Molecular beam epitaxy
Abstract

We report on the photoluminescence quantum efficiency and the lifetime of two Si/CaF2 heterostructures grown by molecular beam epitaxy. The first is a nanocrystalline Si/CaF2 multiquantum well which consists of interacting Si nanocrystallites within Si layers; the second is an annealed Si/CaF2 multiquantum well which can be described as a collection of non-interacting Si nanocrystallites embedded in the CaF2 matrix. While a photoluminescence efficiency of 0.01% has been found in the former, it reaches 1% in the latter. The energy dependence of the PL lifetime differs drastically between both sets of samples. These results are explained in terms of carrier localization.

Published
2000

5. Efficient Visible-Light Emission from Si/CaF2 (111) Heterostructures Grown by Molecular Beam Epitaxy

Author

Louis Vervoort, F. Arnaud d’Avitaya, Franck Bassani, J. C. Vial, I. Mihalcescu, Laboratoire des technologies de la microélectronique (LTM), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des technologies de la microélectronique ( LTM ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Spectrométrie Physique ( LSP ), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Photoluminescence, Silicon, Physics::Optics, chemistry.chemical_element, 02 engineering and technology, 7. Clean energy, 01 natural sciences, Condensed Matter::Materials Science, Optics, 0103 physical sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Condensed Matter::Other, business.industry, Heterojunction, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, chemistry, Quantum dot, Optoelectronics, Light emission, 0210 nano-technology, business, Luminescence, [ PHYS.COND ] Physics [physics]/Condensed Matter [cond-mat], Molecular beam epitaxy, Visible spectrum
Abstract

The elaboration by molecular beam epitaxy of a new luminescing Si-based material is presented, i.e. small grain polycrystalline Si/CaF 2 multi-quantum wells. The static luminescence properties are studied as a function of Si layer thickness, and the time dependent luminescence features as a function of wavelength and temperature. There is a rather striking similarity with the photoluminescence of porous Si, both in spectral position as in decay dynamics. The disappearance of the luminescence when the Si layers become too thick, and the blue-shift of the spectra when the Si layer thickness decreases, favour the quantum confinement hypothesis for the origin of the light emission. The important role of oxygen as passivating agent after ageing in air, is also pointed out.

Published
1995

6. Side chain engineering of organic sensitizers for dye-sensitized solar cells: a strategy to improve performances and stability

Author

Emilio Palomares, Stéphanie Narbey, Damien Joly, Frédéric Oswald, Pascale Maldivi, Yann Kervella, Renaud Demadrille, Laia Pellejà, Maxime Godfroy, Laboratoire de Mécanique et de Rhéologie (LMR), Université de Tours (UT)-Polytech'Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Laboratoire d'Electronique Moléculaire Organique et Hybride (LEMOH), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Conception d’Architectures Moléculaires et Processus Electroniques (CAMPE), Solaronix, rue de l'Ouriette 129, CH-1170 Aubonne, Switzerland, Structures et propriétés d'architectures moléculaire (SPRAM - UMR 5819), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours-Polytech'Tours, Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Polytech'Tours

Subjects
chemistry.chemical_classification, Current generation, Renewable Energy, Sustainability and the Environment, Chemistry, 02 engineering and technology, General Chemistry, Electrolyte, 010402 general chemistry, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Dye-sensitized solar cell, chemistry.chemical_compound, Chemical engineering, Electrode, Ionic liquid, Visible range, Side chain, Organic chemistry, General Materials Science, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Alkyl
Abstract

Four organic dyes specifically designed for application in dye-sensitized solar cells are reported. These dyes are based on a perfectly identical π-conjugated backbone and only differ by the number and the nature of the alkyl chain substituents employed as solubilizing groups. These sensitizers have outstanding light absorption properties in the visible range up to 750 nm on TiO2 and they exhibit quite similar energy level positions. Solar cells fabricated and characterized under exactly the same conditions with iodine-based liquid electrolytes show performances ranging from 6.53% to 9.05%. We highlight that the nature and the number of solubilizing groups have a tremendous impact on the performances of solar cells. The differences in the performance of the four sensitizers can be correlated with the current generation, the formation of aggregates and the dye-loading on the electrodes. We also report solar cells with ionic liquid electrolytes that demonstrate power conversion efficiencies up to 7.81% and a good stability of the performances under accelerated ageing conditions for 7300 hours. We establish that the number and the type of solubilizing groups attached on the π-conjugated backbone of the dyes have a strong influence not only on the performances but also on the lifetimes of the devices; i.e. the dyes that contain lower ratios of alkyl groups lead to the more stable cells.

Published
2017

7. Anisotropic and heterogeneous dynamics in stretched elastomer nanocomposites

Author

Mark Sutton, Gert Heinrich, Françoise Ehrburger-Dolle, Isabelle Morfin, Frédéric Livet, Yuriy Chushkin, Françoise Bley, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire de Physique, Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM), Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Leibniz-Institut für Polymerforschung Dresden e.V. (IPF), Leibniz Association, European Synchrotron Radiation Facility (ESRF), Department of Physics [Montréal], and McGill University = Université McGill [Montréal, Canada]

Subjects
Materials science, Relaxation (NMR), 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Elastomer, 01 natural sciences, 0104 chemical sciences, Condensed Matter::Soft Condensed Matter, Correlation function (statistical mechanics), Dynamic light scattering, Chemical physics, Volume fraction, Particle, Dynamical heterogeneity, 0210 nano-technology, Anisotropy, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], ComputingMilieux_MISCELLANEOUS
Abstract

We use X-ray photon correlation spectroscopy (XPCS) to investigate the dynamics of a stretched elastomer by means of probe particles. The particles dispersed in the elastomer were carbon black or silica aggregates classically used for elastomer reinforcement but their volume fraction is very low (ϕ < 10−2). We show that their dynamics is slower in the direction of the tensile strain than in the perpendicular one. For hydroxylated silica which is poorly wetted by the elastomer, there is no anisotropy. Two-time correlation functions confirm anisotropic dynamics and suggest dynamical heterogeneity already expected from the q−1 behavior of the relaxation times. The height χ* of the peak of the dynamical susceptibility, determined by the normalized variance of the instantaneous correlation function, is larger in the direction parallel to the strain than in the perpendicular one. It also appears that its q dependence changes with the morphology of the probe particle. Therefore, the heterogeneous dynamic probed by the particles is not related only to that of the strained elastomer matrix. In fact, it results from modification of the dynamics of the polymer chains near the surface of the particles and within the aggregate porosity (bound polymer). It is concluded that XPCS is a powerful method for investigating the dynamics, at a given strain, of the bound polymer–particle units which are responsible, at large volume fractions, for the reinforcement.

Published
2019

8. Quadratic phase modulation and diffraction-limited microfocusing generated by pairs of subwavelength dielectric scatterers

Author

Patrice L. Baldeck, Omar Ziane, Safi Jradi, Azeddine Tellal, Olivier Stephan, Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), Lumière, nanomatériaux et nanotechnologies (L2n), Institut Charles Delaunay (ICD), Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and Université des Sciences et de la Technologie Houari Boumediene [Alger] (USTHB)

Subjects
Diffraction, Materials science, micron and sub-micron sizes, QC1-999, Physics::Optics, 02 engineering and technology, Dielectric, 01 natural sciences, Nanomaterials, 010309 optics, Optics, Quadratic phase, 0103 physical sciences, Electrical and Electronic Engineering, visible light, [PHYS]Physics [physics], business.industry, Physics, subwavelength dielectric scatterers, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Modulation, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, diffractive microlens, 0210 nano-technology, business, diffraction limited focusing, Biotechnology, Visible spectrum
Abstract

Diffractive approaches are needed when refractive microlenses reach their focusing limit at the micron-scale in visible light. Previously, we have reported on micron-sized optical lenses based on the diffraction of metallic nanowires. Here, we extend our study to lenses based on pairs of subwavelength dielectric scatterers. Using simulations by two-dimensional finite element method, we demonstrate that focusing holds for pair spacings as small as the wavelength-size. For pairs with distances between inner walls larger than about 1.2λ, the scattered waves generate a quadratic phase modulation on the total propagating field leading to a diffraction-limited focusing i.e. an effective optical lens effect with high numerical aperture. In addition, they have low sidelobe intensities, long depths of focus, and they have a low sensitivity with polarization. For pairs with inner wall distances smaller than about 1.2λ, the focusing phase modulation is accumulated during the propagation through the dielectric pair structure. In this work, we report only on the experimental demonstration for the case of larger wall separation to emphasize on the scattered wave effect on micro-focusing. A pair of parallel polymer lines (cylindrical lens), and a grid of polymer lines (square microlens array) with 2 μm-spacing were fabricated by two-photon induced polymerization. Their focal lengths are comparable to their separating distances, their spot-sizes are 0.37 μm and 0.28 μm at wavelength 530 nm, and their focusing efficiencies are 70% and 60%, respectively.

Published
2019

9. Cellular tension encodes local Src-dependent differential β

Author

De Mets, Richard, Wang, Irène, Balland, Martial, Oddou, Christiane, Moreau, Philippe, Fourcade, Bertrand, Albiges-Rizo, Corinne, Delon, Antoine, Destaing, Olivier, Weaver, Valerie Marie, Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Matière et Systèmes Complexes (MSC (UMR_7057)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut d'oncologie/développement Albert Bonniot de Grenoble (INSERM U823), Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble-EFS-Institut National de la Santé et de la Recherche Médicale (INSERM), Département d'Hématologie [CHU Nantes], Centre hospitalier universitaire de Nantes (CHU Nantes), Dynamique des systèmes d'adhérence et différenciation (DySAD), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), MOTIV, Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), INSERM U823, équipe 1 (DySAD), Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble-EFS-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble-EFS-Institut National de la Santé et de la Recherche Médicale (INSERM)-Dynamique des systèmes d'adhérence et différenciation (DySAD), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)

Subjects
[PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], Integrin, Green Fluorescent Proteins, 02 engineering and technology, Biology, Mechanotransduction, Cellular, Models, Biological, 03 medical and health sciences, Mice, Protein Domains, β3 integrin, Cell Adhesion, Animals, Phosphorylation, Molecular Biology, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, Tension (physics), Integrin beta1, Spectrum Analysis, Integrin beta3, Correction, Cell Biology, Fibroblasts, 021001 nanoscience & nanotechnology, Cell biology, Biomechanical Phenomena, Protein Transport, src-Family Kinases, biology.protein, Brief Reports, 0210 nano-technology, Intracellular, Proto-oncogene tyrosine-protein kinase Src, Micropatterning
Abstract

Integrins are transmembrane receptors that have a pivotal role in mechanotransduction processes by connecting the extracellular matrix to the cytoskeleton. Although it is well established that integrin activation/inhibition cycles are due to highly dynamic interactions, whether integrin mobility depends on local tension and cytoskeletal organization remains surprisingly unclear. Using an original approach combining micropatterning on glass substrates to induce standardized local mechanical constraints within a single cell with temporal image correlation spectroscopy, we measured the mechanosensitive response of integrin mobility at the whole cell level and in adhesion sites under different mechanical constraints. Contrary to β1 integrins, high tension increases β3 integrin residence time in adhesive regions. Chimeric integrins and structure–function studies revealed that the ability of β3 integrins to specifically sense local tensional organization is mostly encoded by its cytoplasmic domain and is regulated by tuning the affinity of its NPXY domains through phosphorylation by Src family kinases.

Published
2018

10. Observation of dual room temperature fluorescence-phosphorescence in air, in the crystal form of a thianthrene derivative

Author

Fernando B. Dias, Algirdas Lazauskas, Anastasia Klimash, David Djurado, Stéphanie Pouget, Ramin Pashazadeh, Agnieszka Swist, Radoslaw Motyka, Juozas V. Grazulevicius, Peter J. Skabara, Piotr Pander, Przemyslaw Data, Jadwiga Sołoducho, Roman Turczyn, Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Service Général des Rayons X (SGX ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Kaunas University of Technology (KTU), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Physics::General Physics, Materials science, Diffusion, Phosphor, 02 engineering and technology, 010402 general chemistry, Photochemistry, 01 natural sciences, chemistry.chemical_compound, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, Thianthrene, ComputingMilieux_MISCELLANEOUS, 021001 nanoscience & nanotechnology, Fluorescence, 0104 chemical sciences, 3. Good health, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Amorphous solid, General Energy, chemistry, 0210 nano-technology, Luminescence, Phosphorescence, Derivative (chemistry)
Abstract

Thianthrenes have been nearly forgotten as phosphors in recent years, but are now coming back, showing their strong potential in luminescent applications. Here, we present a comprehensive photophysical study of a carbazolyl derivative of thianthrene in different matrices and environments. The diffusion of oxygen is slowed down in the rigid environment of thianthrene organic crystals, suppressing their phosphorescence quenching.Triplet–triplet annihilation is also not significantly active in these systems. Both conditions facilitate the observation of simultaneous fluorescence and phosphorescence emissions at room temperature, in air, giving origin to strong white luminescence. Moreover, the color coordinates of the dual fluorescence–phosphorescence white emission, which is observed only in rigid amorphous media and in crystals, can be tuned.

Published
2018

11. Visible and near-infrared organic photosensitizers comprising isoindigo derivatives as chromophores: synthesis, optoelectronic properties and factors limiting their efficiency in dye solar cells

Author

Emilio Palomares, Cyril Aumaitre, Núria López, Olivier Bardagot, Renaud Demadrille, Florent Caffy, Jesús Jover, Cristina Rodríguez-Seco, Yann Kervella, Synthèse, Structure et Propriétés de Matériaux Fonctionnels, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institute of Chemical Research of Catalonia (ICIQ), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Universitat de Barcelona, Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Solar cells, Materials science, Bacteris fotosintetitzadors, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, 7. Clean energy, law.invention, chemistry.chemical_compound, [SPI]Engineering Sciences [physics], law, Ultrafast laser spectroscopy, Solar cell, Molecule, [CHIM]Chemical Sciences, General Materials Science, Triiodide, Spectroscopy, Absorption (electromagnetic radiation), ComputingMilieux_MISCELLANEOUS, Renewable Energy, Sustainability and the Environment, business.industry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Energy conversion efficiency, [SPI.NRJ]Engineering Sciences [physics]/Electric power, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, Chromophore, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, Photosynthetic bacteria, Optoelectronics, Cèl·lules solars, 0210 nano-technology, business
Abstract

The development of ruthenium-free organic photosensitizers showing panchromatic absorption up to the near-infrared (NIR) region for application in dye-sensitized solar cells (DSSCs) is still scarce. Among the sensitizers with absorption beyond 700 nm and developed for DSSCs, only zinc-phthalocyanine and boron-dibenzopyrromethene-based dyes have been able to reach efficiencies as high as 6%. Here we report metal-free organic dyes based on isoindigo, thieno-isoindigo or benzo-thieno-isoindigo chromophores that absorb in the UV-visible and NIR spectral range up to 900 nm. These molecules, that exhibit purple, blue, or green hues, were used to sensitize TiO2 mesoporous electrodes in order to fabricate DSSCs with an iodide/triiodide-based electrolyte. Advanced photophysical characterizations, including charge extraction, transient photovoltage, and laser transient absorption spectroscopy experiments, combined with density functional theory modeling and computational investigations allow us to fully unravel the interfacial processes at the origin of the solar cell performances and to identify the limiting factors. A power conversion efficiency as high as 7% associated with a Jsc close to 19 mA cm−2 was obtained with one of the dyes, which is comparable to those of the best panchromatic organic dyes reported so far. We also demonstrate in this work that the Voc of the solar cells is linearly correlated to the dipolar moments of the oxidized dyes, the molecules possessing larger dipoles leading to the highest Voc values.

Published
2018

12. Sarcoïdoses et fibroses pulmonaires idiopathiques : les analyses minéralogiques par imagerie LIBS et MEB orientent le diagnostic étiologique

Author

Jean-Luc Coll, Vincent Motto-Ros, Marine Leprince, Vincent Bonneterre, Mickaël Catinon, Michel Vincent, Lucie Sancey, Benoit Busser, Frédéric Pelascini, UF Cancérologie biologique et biothérapie, CHU Grenoble, Laboratoire d'Ecologie Alpine (LECA ), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CRITT Matériaux Alsace, Institut d'oncologie/développement Albert Bonniot de Grenoble (INSERM U823), Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble-EFS-Institut National de la Santé et de la Recherche Médicale (INSERM), Radiopharmaceutiques biocliniques, Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR130, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Environnement et Prédiction de la Santé des Populations (TIMC-IMAG-EPSP), Techniques de l'Ingénierie Médicale et de la Complexité - Informatique, Mathématiques et Applications, Grenoble - UMR 5525 (TIMC-IMAG), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Centre Hospitalier Universitaire [Grenoble] (CHU)

Subjects
[SDV]Life Sciences [q-bio], Public Health, Environmental and Occupational Health, 02 engineering and technology, 010501 environmental sciences, 021001 nanoscience & nanotechnology, 0210 nano-technology, 01 natural sciences, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

Introduction L’exposition professionnelle et/ou environnementale a des poussieres minerales inhalees peut favoriser des pathologies comme la sarcoidose, les pneumopathies infiltratives associees a des connectivites et des fibroses. Ces pathologies sont cependant le plus souvent considerees comme idiopathiques, or parmi elles, un certain nombre sont d’origine environnementale. Par manque de temps et de moyens techniques et humains, l’etiologie de ces pathologies respiratoires idiopathiques n’est pas recherchee. Nous cherchons a caracteriser la nature des (nano)-particules contenues dans divers echantillons pulmonaires de ces patients. Methodes Des patients souffrant de pathologies pulmonaires etiquetees idiopathiques ont ete inclus apres avoir signe un formulaire de consentement eclaire. Les echantillons biopsiques preleves dans le cadre du soin quotidien inclus en paraffine ou FFPE ont ete analyses par imagerie multi-elementaire LIBS ( laser-induced breakdown spectroscopy ) couplee a une analyse mineralogique MEB-EDX (microscopie electronique associee a la microanalyse par energie dispersive de rayons X). Pour chaque echantillon, nous avons recherche la presence d’elements tels Fe, Si, Ti, Cu, Al, Cr, Mn, etc. Resultats Nous avons retrouve des accumulations de metaux exogenes tels Cr, Si, et Ti dans plusieurs echantillons. La presence d’images histologiques realisees sur sections adjacentes permet de localiser precisement ces elements dans des zones granulomateuses, inflammatoires, et meme dans du parenchyme pulmonaire « histologiquement normal ». Ces resultats ont ete confirmes par l’analyse de la composition et de la taille des particules en MEB-EDX. Dans certains cas, la nature des elements exogenes retrouves par les analyses mineralogiques etait en accord avec les expositions professionnelles/environnementales collectees lors des interrogatoires. Conclusion Nous avons developpe une approche technologique innovante qui permet de connaitre la composition elementaire des (nano) particules presentes dans le tissu pulmonaire, ou dans tout autres tissu. L’analyse LIBS permet d’identifier et localiser rapidement la quasi-totalite des elements chimiques au sein des tissus, avec une bonne sensibilite (∼ppm). Les images multi-elementaires LIBS sont superposables avec les images histologiques de microscopie optique utilisee par les anatomo-pathologistes. Il existe une bonne complementarite avec l’analyse mineralogique conventionnelle effectuee par MEB-EDX. L’analyse LIBS couplee a l’analyse MEB-EDX permet d’objectiver les suspicions d’empoussierement professionnel de patients exposes mais aussi de reveler et orienter la recherche d’etiologie de certaines pathologies idiopathiques.

Published
2018

13. Dithienylpyrazine-based photosensitizers: Effect of swapping a connecting unit on optoelectronic properties and photovoltaic performances

Author

Maxime Godfroy, Stéphanie Narbey, Yann Kervella, Emilio Palomares, Pascale Maldivi, Lydia Cabau, Renaud Demadrille, Damien Joly, Cyril Aumaitre, Florent Caffy, Frédéric Oswald, Laia Pellejà, Laboratoire d'Electronique Moléculaire Organique et Hybride (LEMOH), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Synthèse, Structure et Propriétés de Matériaux Fonctionnels, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Reconnaissance Ionique et Chimie de Coordination (RICC), Solaronix, rue de l'Ouriette 129, CH-1170 Aubonne, Switzerland, Institute of Chemical Research of Catalonia (ICIQ), Laboratoire de Mécanique et de Rhéologie (LMR), Université de Tours (UT)-Polytech'Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours-Polytech'Tours, and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Polytech'Tours

Subjects
General Chemical Engineering, 02 engineering and technology, Electrolyte, 010402 general chemistry, Photochemistry, 01 natural sciences, 7. Clean energy, Redox, chemistry.chemical_compound, Quinoxaline, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Molecule, [CHIM]Chemical Sciences, Absorption (electromagnetic radiation), ComputingMilieux_MISCELLANEOUS, business.industry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Process Chemistry and Technology, Photovoltaic system, Energy conversion efficiency, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Dye-sensitized solar cell, chemistry, Optoelectronics, 0210 nano-technology, business
Abstract

Three D-π-A-π-A organic dyes (QX1, DTQX1 and TPZ1) were synthesized and used as photosensitizers in Dye Sensitized Solar Cells (DSSC). The molecules only vary by the nature of the linker connecting a side dithienylpyrazine motive to a triarylamine-based donating unit and a phenylcyano-acrylic acid to provide the anchoring function. By simply swapping the aromatic connecting unit the range and intensity of the absorption of the compounds can be tuned, leading to orange and green dyes. The energy levels of the frontier orbitals are well-positioned for use in DSSC with TiO2 as the photoanode and I−/I3− as a redox couple in the electrolyte. Solar cells based on these sensitizers showed a power conversion efficiency (PCE) of up to 8.6% for the dyes with the narrower absorption. The lower PCE with TPZ1 is attributed to the more quinoidal nature of the π-conjugated backbone, which leads to a less favorable spatial distribution of the frontier orbitals and results in lower electron injection and higher recombination rate.

Published
2017

14. Dynamic Structuration of Physical Chitosan Hydrogels

Author

Philippe Durand, Jean-Pierre Puaux, Cyrille Rochas, Alin Alexandru Enache, Marie-Hélène Perrard, Nicolas Sereni, Thierry Delair, Laurent David, Grigore Bozga, Guillaume Sudre, Alexandra Montembault, Ingénierie des Matériaux Polymères (IMP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet [Saint-Étienne] (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut de Génomique Fonctionnelle de Lyon (IGFL), École normale supérieure - Lyon (ENS Lyon)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, University Politehnica of Bucharest [Romania] (UPB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Ingénierie des Matériaux Polymères - Laboratoire des Matériaux Polymères et des Biomatériaux (IMP-LMPB), Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut de Chimie du CNRS (INC), European Synchrotron Radiation Facility (ESRF), Institut de Chimie des Substances Naturelles (ICSN), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Lyon (ENS Lyon), CNRS - BioMérieux, Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure de Lyon (ENS de Lyon)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL)

Subjects
Materials science, Morphology (linguistics), 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Light scattering, Chitosan, chemistry.chemical_compound, Polymer chemistry, Electrochemistry, General Materials Science, Spectroscopy, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, Aqueous solution, Molar mass, technology, industry, and agriculture, Surfaces and Interfaces, Polymer, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 0104 chemical sciences, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Chemical engineering, Self-healing hydrogels, 0210 nano-technology
Abstract

We studied the microstructure of physical chitosan hydrogels formed by the neutralization of chitosan aqueous solutions highlighting the structural gradients within thick gels (up to a thickness of 16 mm). We explored a high polymer concentrations range (Cp ≥ 1.0% w/w) with different molar masses of chitosan and different concentrations of the coagulation agent. The effect of these processing parameters on the morphology was evaluated mainly through small-angle light scattering (SALS) measurements and confocal laser scanning microscopy (CLSM) observations. As a result, we reported that the microstructure is continuously evolving from the surface to the bulk, with mainly two structural transitions zones separating three types of hydrogels. The first zone (zone I) is located close to the surface of the hydrogel and constitutes a hard (entangled) layer formed under fast neutralization conditions. It is followed by a second zone (zone II) with a larger thickness (∼3–4 mm), where in some cases large pores or c...

Published
2017

15. Simple and economic elaboration of high purity CaCO 3 particles for bone graft applications using a spray pyrolysis technique

Author

Nicolas Ratel-Ramond, Marc Verelst, Chiara Venturini, David Neumeyer, André Gourdon, Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, ChromaLys S.A.S., Groupe NanoSciences (CEMES-GNS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Matériaux Multi-fonctionnels et Multi-échelles (CEMES-M3), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3)

Subjects
Materials science, Dispersity, Biomedical Engineering, Sintering, [SDV.CAN]Life Sciences [q-bio]/Cancer, 02 engineering and technology, [CHIM.THER]Chemical Sciences/Medicinal Chemistry, engineering.material, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Chemical reaction, chemistry.chemical_compound, Forensic engineering, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, General Materials Science, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Porosity, Lime, Thermal decomposition, General Chemistry, General Medicine, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Calcium carbonate, Chemical engineering, chemistry, engineering, 0210 nano-technology, Pyrolysis
Abstract

International audience; Materials for bone grafting are a major health stake today. The existing synthetic materials only partially answer to the requirements for such uses and do not provide a real alternative solution to the classical way consisting of the reuse of natural osseous materials, known to create other problems. In the present work, we have prepared calcium carbonate powders using spray pyrolysis in the perspective to realize ideal and multi-purposed bricks to form bone graft materials, by bottom-up approaches, using classical techniques. The chemical reactions involved in the synthesis process consist in the thermal decomposition of calcium acetate. This precursor, a classical food additive, is known to be non toxic, easy to use and very cheap. Morphological and chemical characterization was conducted on the obtained materials. Depending on the pyrolysis temperature, we observed partial decomposition of calcium acetate or lime formation. An annealing step is consequently required to finalize the transformation. Finally, it appears that annealed products are pure calcite particles, having a spherical morphology and possessing a low dispersity in the micron size range. These particles exhibit an original internal structure, reinforcing and ensuring the preservation of their morphological characteristics during the sintering process. Furthermore, a porosity value compatible with drug carrier capabilities was measured on the obtained products. All these qualities allow us to consider a multi-purpose use of these particles in almost all types of bone graft materials.

Published
2017

16. Two-photon lithography in visible and NIR ranges using multibranched-based sensitizers for efficient acid generation

Author

Arnaud Spangenberg, Davy-Louis Versace, Hongting Pu, Tiffanie Leclerc, Olivier Soppera, Decheng Wan, Jean-Pierre Malval, Jianchao Xie, Haiyan Pan, Ming Jin, Olivier Poizat, Patrice L. Baldeck, Stephan Knopf, Tongji University, Institut de Science des Matériaux de Mulhouse (IS2M), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), and Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE)

Subjects
Materials science, Exciton, 02 engineering and technology, General Chemistry, Chromophore, 010402 general chemistry, 021001 nanoscience & nanotechnology, Multiphoton lithography, Triphenylamine, Photochemistry, Branching (polymer chemistry), 01 natural sciences, Fluorescence, 3. Good health, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, Polymerization, chemistry, Materials Chemistry, 0210 nano-technology, Order of magnitude
Abstract

We investigated methodically the one- and two-photon absorption properties of a series of multibranched triphenylamine-based chromophores incorporating 4-(methylthio)styryl fragments as external substituents. Some relevant structure–property relationships relative to these highly fluorescent compounds have been derived based on emission anisotropy measurements, quantum chemical calculations and the use of the exciton coupling theory. Even though branching effects lead to a cooperative enhancement of the two-photon absorption (2PA), all compounds exhibit relatively low-to-moderate 2PA cross-sections (δ ≤ 100 GM) in the NIR region. However, the ‘so-called’ one-photon resonance enhancement effect leads to a remarkable increase of δ by more than one order of magnitude in the visible range. This strong 2PA ability has been associated with an efficient photosensitization of iodonium salt to elaborate a new bicomponent photoacid generator, which is readily two-photon activable at 532 nm. In the visible range, the strong enhancement of the efficiency of the two-photon induced polymerization is clearly demonstrated as compared with that observed in the NIR region.

Published
2014

17. Nanocarriers with ultrahigh chromophore loading for fluorescence bio-imaging and photodynamic therapy

Author

Yann Leverrier, Pierre-Henri Lanoë, Guillaume Micouin, Jacqueline Marvel, Patrice L. Baldeck, Cristina Cepraga, Frédéric Lerouge, Julien R. G. Navarro, Denis Chateau, Sophie Marotte, Chantal Andraud, Stephane Parola, Frédéric Chaput, Arnaud Favier, Kenji Kamada, Marie-Thérèse Charreyre, Cyrille Monnereau, Laboratoire de Chimie - UMR5182 (LC), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Ingénierie des Matériaux Polymères (IMP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des technologies de la microélectronique (LTM), Université Joseph Fourier - Grenoble 1 (UJF)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de la matière condensée (LPMC), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Immunité infection vaccination (I2V), Université de Lyon-Université de Lyon-IFR128-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR128-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL)

Subjects
Fluorescence-lifetime imaging microscopy, Materials science, medicine.medical_treatment, Biophysics, Bio-imaging, Nanoparticle, Bioengineering, Nanotechnology, Photodynamic therapy, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Fluorescence, Biomaterials, PDT, Cell Line, Tumor, medicine, Humans, Photosensitizer, chemistry.chemical_classification, Molecular Structure, Optical Imaging, [CHIM.MATE]Chemical Sciences/Material chemistry, Polymer, Chromophore, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.POLY]Chemical Sciences/Polymers, Photochemotherapy, chemistry, Mechanics of Materials, Ceramics and Composites, Nanoparticles, Gold, Nanocarriers, 0210 nano-technology
Abstract

International audience; We describe the design of original nanocarriers that allows for ultrahigh chromophore loading while maintaining the photo-activity of each individual molecule. They consist in shells of charged biocompatible polymers grafted on gold nanospheres. The self-organization of extended polymer chains results from repulsive charges and steric interactions that are optimized by tuning the surface curvature of nanoparticles. This type of nano-scaffolds can be used as light-activated theranostic agents for fluorescence imaging and photodynamic therapy. We demonstrate that, labeled with a fluorescent photosensitizer, it can localize therapeutic molecules before triggering the cell death of B16-F10 melanoma with an efficiency that is similar to the efficiency of the polymer conjugate alone, and with the advantage of extremely high local loading of photosensitizers (object concentration in the picomolar range).

Published
2013

18. Two DNA nanomachines map pH changes along intersecting endocytic pathways inside the same cell

Author

Yamuna Krishnan, Souvik Modi, Sunaina Surana, Clément Nizak, Saheli Halder, Structure and Dynamics of Nucleic Acids, National Centre for Biological Sciences, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), National Centre for Biological Sciences [TIFR] (NCBS), and Tata Institute for Fundamental Research (TIFR)

Subjects
Endosome, Endocytic cycle, Cell, Biomedical Engineering, Golgi Apparatus, Bioengineering, Nanotechnology, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Biosensing Techniques, Endosomes, 02 engineering and technology, Living cell, 010402 general chemistry, Endocytosis, Ph changes, 01 natural sciences, chemistry.chemical_compound, Organelle, medicine, Humans, General Materials Science, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], Electrical and Electronic Engineering, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, DNA, Hydrogen-Ion Concentration, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Nanostructures, 0104 chemical sciences, medicine.anatomical_structure, chemistry, Biophysics, 0210 nano-technology, Metabolic Networks and Pathways, trans-Golgi Network
Abstract

International audience; DNA is a versatile scaffold for molecular sensing in living cells, and various cellular applications of DNA nanodevices have been demonstrated. However, the simultaneous use of different DNA nanodevices within the same living cell remains a challenge. Here, we show that two distinct DNA nanomachines can be used simultaneously to map pH gradients along two different but intersecting cellular entry pathways. The two nanomachines, which are molecularly programmed to enter cells via different pathways, can map pH changes within well-defined subcellular environments along both pathways inside the same cell. We applied these nanomachines to probe the pH of early endosomes and the trans-Golgi network, in real time. When delivered either sequentially or simultaneously, both nanomachines localized into and independently captured the pH of the organelles for which they were designed. The successful functioning of DNA nanodevices within living systems has important implications for sensing and therapies in a diverse range of contexts.

Published
2013

19. Clusters of red blood cells in microcapillary flow: hydrodynamic versus macromolecule induced interaction

Author

Chaouqi Misbah, Gwennou Coupier, Othmane Aouane, Viviana Clavería, Christian Wagner, Thomas John, Marine Thiébaud, Manouk Abkarian, Centre de Biochimie Structurale [Montpellier] (CBS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), ExperimentalPhysik, Universität des Saarlandes [Saarbrücken], Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), DYnamique des Fluides COmplexes et Morphogénèse [Grenoble] (DYFCOM-LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Statistique de l'ENS (LPS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM), LIPHY-DYFCOM, Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Université Paris Diderot - Paris 7 (UPD7)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Erythrocytes, FOS: Physical sciences, 02 engineering and technology, Condensed Matter - Soft Condensed Matter, 01 natural sciences, 0103 physical sciences, Cluster (physics), Humans, Physics - Biological Physics, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], 010306 general physics, ComputingMilieux_MISCELLANEOUS, Chemistry, Vesicle, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 3. Good health, Biological Physics (physics.bio-ph), Physiological flow, Hydrodynamics, Biophysics, Soft Condensed Matter (cond-mat.soft), Stress, Mechanical, Adhesive, 0210 nano-technology, Macromolecule
Abstract

We present experiments on RBCs that flow through microcapillaries under physiological conditions. We show that the RBC clusters form as a subtle imbrication between hydrodynamics interaction and adhesion forces because of plasma proteins. Clusters form along the capillaries and macromolecule-induced adhesion contribute to their stability. However, at high yet physiological flow velocities, shear stresses overcome part of the adhesion forces, and cluster stabilization due to hydrodynamics becomes stronger. For the case of pure hydrodynamic interaction, cell-to-cell distances have a pronounced bimodal distribution. Our 2D-numerical simulations on vesicles captures the transition between adhesive and non-adhesive clusters at different flow velocities., Comment: 12 pages, 11 figures

Published
2016

20. Bilayer structures in dioctadecyldimethylammonium bromide/oleic acid dispersions

Author

Sylwia Kedracka-Krok, Mariusz Kepczynski, Jan Bednar, Joanna Lewandowska, Karolina Witkowska, Veronika Mistrikova, Maria Nowakowska, Paweł Wydro, Faculty of Chemistry, Uniwersytet Jagielloński w Krakowie = Jagiellonian University (UJ), Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
DODAB, Isothermal microcalorimetry, MESH: Viscosity, Lipid Bilayers, Analytical chemistry, 02 engineering and technology, 010402 general chemistry, Mole fraction, 01 natural sciences, Biochemistry, Microviscosity, MESH: Quaternary Ammonium Compounds, chemistry.chemical_compound, Differential scanning calorimetry, Microscopy, Electron, Transmission, Bromide, Microscopy, Interference, Langmuir monolayer, MESH: Microscopy, Interference, Molecular Biology, vesicles, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Calorimetry, Differential Scanning, Viscosity, Chemistry, MESH: Lipid Bilayers, Bilayer, Vesicle, MESH: Calorimetry, Differential Scanning, MESH: Oleic Acid, Organic Chemistry, Cell Biology, cryo-transmission electron microscopy, 021001 nanoscience & nanotechnology, microcalorimetry, 0104 chemical sciences, Quaternary Ammonium Compounds, Membrane, MESH: Microscopy, Electron, Transmission, Thermodynamics, MESH: Thermodynamics, 0210 nano-technology, Oleic Acid
Abstract

International audience; This paper reports on the properties of bilayers composed of dioctadecyldimethylammonium bromide (DODAB) and oleic acid (OA) at various molar ratios. The mole fraction of OA, X(OA), was varied in the range of 0-1 and the total lipid content was constant and equal to 10 mM. The DODAB/OA dispersions were extruded at a temperature higher than that of the gel-liquid transition of DODAB. The morphology of bilayer structures formed in the dispersions was inspected using a cryogenic transmission electron microscopy (cryo-TEM) and a differential interference contrast microscopy (DIC). The observations revealed that the incorporation of OA into DODAB bilayer results in a decrease of the membrane curvature. Anisotropy measurements using 1,6-diphenylhexatriene (DPH) as a rotator probe demonstrated that the DODAB/OA membrane microviscosity decreased considerably for X(OA)>0.4. The thermal behavior of DODAB/OA membranes has been studied by differential scanning calorimetry (DSC). In the case of the systems in which X(OA)

Published
2011

21. Two-dimensional constriction flows of foams

Author

Benjamin Dollet, François Graner, Sian Jones, Yi Jiang, Simon Cox, N. Slosse, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Surface (mathematics), Evolver, Materials science, Scale (ratio), Quasi-2D foam, Bubble, Rounding, Texture tensor, 02 engineering and technology, Mechanics, 021001 nanoscience & nanotechnology, 01 natural sciences, 010305 fluids & plasmas, Physics::Fluid Dynamics, 2D constrictionflow, Colloid and Surface Chemistry, Flow (mathematics), 0103 physical sciences, Potts model, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Texture (crystalline), Surface evolver, 0210 nano-technology
Abstract

International audience; The flow of a quasi-two-dimensionalfoam through a constriction is described. The bubble velocity and elongation (texture) is compared between two sets of experiments and two different quasi-static simulations using Surface Evolver and Potts model. The simulations capture the effect of changing the degree of rounding of the corners of the flow geometry and the length of the constricted region. Validation of these simulation methods offers the possibility to easily vary many parameters of interest and to explore parameter ranges that are inaccessible to experiments such as low liquid fraction and slow velocity. Perspectives include characterisations of a 3D flow at the bubble scale.

Published
2011

22. Laser microstructuration of three-dimensional enzyme reactors in microfluidic channels

Author

Clément Nizak, Teodora Scheul, Patrice L. Baldeck, Olivier Stéphan, Simion Astilean, Monica Iosin, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Faculty of Physics, Babes-Bolyai University [Cluj-Napoca] (UBB), Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), and Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)

Subjects
Materials science, Polydimethylsiloxane, [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], 010401 analytical chemistry, Microfluidics, Nanotechnology, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Laser, 01 natural sciences, Fluorescence spectroscopy, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, law.invention, chemistry.chemical_compound, chemistry, law, Femtosecond, Materials Chemistry, BODIPY, Microreactor, 0210 nano-technology, Eosin Y
Abstract

International audience; In this paper, we report on the fabrication of three-dimensional (3D) enzymatic microreactors within polydimethylsiloxane microfluidic channels through a photocrosslinking mechanism mediated by the two-photon absorption process at the focal point of pulse lasers, i.e., a sub-nanosecond Nd:YAG microlaser or a femtosecond Ti:Sapphire laser. This approach allows the building of localized 3D trypsin structures with submicron resolution. The fabrication of two different trypsin structures was successfully demonstrated using Eosin Y and Flavin Adenine Dinucleotide as biological photosensitizers: (i) arrays of 3D cylindrical rows and (ii) 3D woodpile structure. The enzymatic activity of the fabricated structures was evaluated by fluorescence spectroscopy using BODIPY FL casein as fluorogenic substrate. The real time investigation of the peptide cleavage into the microfluidic channel demonstrated that the fabricated trypsin microstructures maintain their catalytic activity. This approach opens up the way to complex multistep enzymatic reactions in well-localized regions of microfluidic devices, with great importance in health screening and biomedical diagnostics.

Published
2010

23. Transport of free surface liquid films and drops by external ratchets and self-ratcheting mechanisms

Author

Uwe Thiele, Karin John, Department of Mathematical Sciences [Loughborough], Loughborough University, DYFCOM, Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
vibrated substrates, heterogeneous substrates, Microfluidics, Ratchet, microfluidics, Liquid dielectric, FOS: Physical sciences, General Physics and Astronomy, 02 engineering and technology, Condensed Matter - Soft Condensed Matter, 01 natural sciences, law.invention, law, 0103 physical sciences, Statistical physics, Physical and Theoretical Chemistry, 010306 general physics, Physics::Biological Physics, Chemistry, PACS: 05.60.-k, 68.15.+e, 47.61.-k, 47.20.Ma, 47.55.Dz, 68.08.-p, Mechanics, 021001 nanoscience & nanotechnology, Vibration, Capacitor, fluid ratchets, droplet transport, Free surface, Harmonic, Soft Condensed Matter (cond-mat.soft), Particle, 0210 nano-technology, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract

We discuss the usage of ratchet mechanisms to transport a continuous phase in several micro-fluidic settings. In particular, we study the transport of a dielectric liquid in a heterogeneous ratchet capacitor that is periodically switched on and off. The second system consists of drops on a solid substrate that are transported by different types of harmonic substrate vibrations. We argue that the latter can be seen as a self-ratcheting process and discuss analogies between the employed class of thin film equations and Fokker-Planck equations for transport of discrete objects in a 'particle ratchet'., 10 pages, 13 figures

Published
2010

24. Ruthenium(II) Complexes for Two-Photon Absorption-Based Optical Power Limiting

Author

Patrice L. Baldeck, Jacques A. Delaire, Jérôme Chauvin, Bertrand Cao, Jean-Christophe Mulatier, Chantal Andraud, Didier Riehl, Gilles Lemercier, Camille Girardot, Laboratoire de Chimie - UMR5182 (LC), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Délégation générale de l'armement (DGA), Ministère de la Défense, Laboratoire de Photophysique et Photochimie Supramoléculaires et Macromoléculaires (PPSM), École normale supérieure - Cachan (ENS Cachan)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Département de Chimie Moléculaire (DCM), Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC)

Subjects
Photochemistry, chemistry.chemical_element, Optical power, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Two-photon absorption, Ruthenium, law.invention, law, Organometallic Compounds, Physical and Theoretical Chemistry, Absorption (electromagnetic radiation), Fluorenes, Photons, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Chemistry, Ligand, Lasers, Nonlinear optics, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Laser, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, 3. Good health, Solubility, Luminescent Measurements, 0210 nano-technology, Excitation
Abstract

International audience; Long-lived excitation: Novel bifluorene-substituted 1,10-phenanthroline-based RuII coordination complexes are presented (see picture). They fulfil several requirements for optimized optical power limiting in the visible-NIR, as they are stable, soluble and transparent at low laser fluences. The two-photon absorption of these complexes are strongly related to those of the ligand.

Published
2008

25. Polyelectrolyte Complexes from Polysaccharides: Formation and Stoichiometry Monitoring

Author

and Alain Domard, Laurent David, Thierry Delair, Cyrille Rochas, Alexandre Drogoz, Ingénierie des Matériaux Polymères - Laboratoire des Matériaux Polymères et des Biomatériaux (IMP-LMPB), Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut de Chimie du CNRS (INC), Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Light, Macromolecular Substances, Inorganic chemistry, macromolecular substances, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Chitosan, Electrolytes, chemistry.chemical_compound, Dynamic light scattering, Polysaccharides, Electrochemistry, Scattering, Radiation, Organic chemistry, General Materials Science, Colloids, Toluidine, Sulfate, Spectroscopy, chemistry.chemical_classification, Molar mass, Spectrum Analysis, X-Rays, Dextran Sulfate, technology, industry, and agriculture, Surfaces and Interfaces, Polymer, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Polyelectrolyte, 0104 chemical sciences, [CHIM.POLY]Chemical Sciences/Polymers, Dextran, chemistry, 0210 nano-technology
Abstract

International audience; Colloids were obtained from non-stoichiometric polyelectrolyte complexes with two polysaccharides of opposite charge: chitosan and dextran sulfate (DS) as the polycation and polyanion, respectively. The complexes were elaborated by a one-shot addition of the polymer in default to the one in excess. The colloids were positively or negatively charged according to the nature of the polymer in excess. Dynamic light scattering (DLS) demonstrated that particles were formed at a very early stage in the complexation process. The consumption of the excess polyelectrolyte was monitored with a dye assay specific for dextran sulfate (toluidine blue) or chitosan (orange II). From these experiments, two different mechanisms of colloidal PEC formation were evidenced, according to the nature of the polymer in excess. On adding chitosan to DS in excess, regular consumption of the polyanion was observed at a constant stoichiometry, in the 1.5 to 1.85 range (sulfate residues for one glucosamine group), according to the molar mass of the polycation. When DS was added to chitosan in excess, the overall stoichiometry varied from ca. 6 (glucosamine residues for one sulfate group) down to 1 as the charge molar mixing ratio R = n+/n- decreased from 20 to 1. The existence of various mechanisms, according to the nature of the polymer in excess, could be attributed to the differences in chemical reactivity (strong vs low) of the ion in excess and the conformation and flexibility of the macromolecular chains related to their electrostatic potential.

Published
2007

26. Real time in situ hard X-ray texture evolution during the annealing of rolled CuNi tapes

Author

P. Bastie, J.-L. Soubeyroux, A. Girard, Laboratoire SYstèmes et Matériaux pour la MEcatronique (SYMME), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Consortium de Recherches pour l'Emergence des Technologies Avancées (CRETA), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, Magnétisme et Supraconductivité (MagSup), Institut Néel (NEEL), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)

Subjects
High-temperature superconductivity, Materials science, Annealing (metallurgy), Alloy, 02 engineering and technology, engineering.material, 01 natural sciences, law.invention, law, 0103 physical sciences, General Materials Science, Neutron, Composite material, 010306 general physics, coated conductor, Scattering, 020502 materials, Metallurgy, Detector, X-ray, Recrystallization (metallurgy), [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, 0205 materials engineering, engineering, Physics::Accelerator Physics, CuNi alloys
Abstract

A new real time in-situ scattering method to study texture evolution kinetics is detailed. The technique is adapted from an existing set up used at the Institut Laue-Langevin neutron facility to check monochromators. It uses a white hard X-ray beam and works in transmission geometry. A 2D detector allows following of the recrystallization phenomena. A study of the annealing behavior of copper-nickel alloy rolled tapes, used as a substrate for high temperature superconductors, is presented.

Published
2007

27. Characterization of high density matrix microwave argon plasmas by laser absorption and electric probe diagnostics

Author

N Sadeghi, A. Bès, Jean-Marc Pelletier, Ana Lacoste, L Latrasse, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Argon, Acoustics and Ultrasonics, Chemistry, chemistry.chemical_element, 02 engineering and technology, Plasma, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Ion source, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, symbols.namesake, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Physics::Plasma Physics, Ionization, 0103 physical sciences, symbols, Langmuir probe, Electron temperature, Plasma diagnostics, Atomic physics, 0210 nano-technology, Microwave
Abstract

International audience; Microwave plasma sources distributed on a planar matrix configuration can produce uniform bi-dimensional plasmas free from magnetic field in the 100 Pa pressure range. In argon, such uniform sheets of plasma have been obtained with ion densities in the range of 1012 to 1013 cm-3 with microwave power ranging from 0.4 to 2 kW. The electrical characterization of the plasma has been investigated using a cylindrical Langmuir probe. A first feature concerns the plasma potential that exhibits quite high values due to the large increase in the electron temperature towards the source plane where the microwave electric field is applied. Secondly, the decrease in the electron temperature observed when increasing the microwave power can be justified by the apparition of multi-step ionization mechanisms via metastable and higher excited states of Ar atom. The concentration and temperature of Ar(3P2) metastables have been measured by laser diode absorption spectroscopy. The results indicate that the presence of Ar(3P2) metastables is significant at 2 cm from the source plane with concentration and temperature values varying from 1010 to 1011 cm-3 and from 500 K to 1300 K, respectively, as functions of argon pressure and microwave power. An analytical model using a few simplifying assumptions provides a plasma picture in good agreement with the experimental results.

Published
2007

28. Photoluminescence of 'dark' excitons in CdMnTe quantum well, embedded in a microcavity

Author

Marta Martín, Luis Viña, Régis André, Adalberto Brunetti, Denis Scalbert, Maria Vladimirova, Alberto Amo, Dario Ballarini, Groupe d'étude des semiconducteurs (GES), Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Photoluminescence, excitons, Exciton, 02 engineering and technology, Exciton-polaritons, 01 natural sciences, Condensed Matter::Materials Science, 0103 physical sciences, General Materials Science, Emission spectrum, Electrical and Electronic Engineering, 010306 general physics, Quantum well, Biexciton, Condensed Matter::Quantum Gases, Physics, Condensed matter physics, Condensed Matter::Other, RESONANCE, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Condensed Matter Physics, diluted magnetic semiconductors, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], photoluminescence, Spin-flip, 0210 nano-technology, Excitation
Abstract

International audience; A diluted magnetic semiconductor (DMS) quantum well (QW) microcavity operating in the limit of the strong coupling regime is studied by magnetoptical experiments. The interest of DMS QW relies on the possibility to vary the excitonic, resonance over a wide range of energies by applying an external magnetic field, typically about 30 meV for 5 T in our sample. In particular, the anticrossing between the QW exciton and the cavity mode can be tuned by the external field. We observe the anticrossing and formation of exciton polaritons in magneto-reflectivity experiments. In contrast, magneto-luminescence exhibits purely excitonic character. Under resonant excitation conditions an additional emission line is observed at the energy of the dark exciton. The creation of dark excitons is made possible due to heavy hole-light hole mixing in the QW. The emission at this energy could be due to a combined spin flip of an electron and a bright exciton recombination. (c) 2007 Elsevier Ltd. All rights reserved.

Published
2007

29. Sub-10 nm Scale Nanostructures in Self-Organized Linear Di- and Triblock Copolymers and Miktoarm Star Copolymers Consisting of Maltoheptaose and Polystyrene

Author

Redouane Borsali, Issei Otsuka, Toyoji Kakuchi, Cyrille Rochas, Toshifumi Satoh, Yao Zhang, Takuya Isono, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), ECE Department, (ECE), University of California [Davis] (UC Davis), University of California-University of California, Hokkaido University [Sapporo, Japan], Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and Hokkaido Univ, Grad Sch Engn

Subjects
Materials science, Nanostructure, Polymers and Plastics, 02 engineering and technology, Flory–Huggins solution theory, Degree of polymerization, 010402 general chemistry, 01 natural sciences, Inorganic Chemistry, chemistry.chemical_compound, Polymer chemistry, Materials Chemistry, Copolymer, Lamellar structure, Thin film, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, ComputingMilieux_MISCELLANEOUS, Organic Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Crystallography, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Volume fraction, Polystyrene, 0210 nano-technology
Abstract

The present paper describes the sub-10 nm scale self-assembly of AB-type diblock, ABA-type triblock, and A2B-type miktoarm star copolymers consisting of maltoheptaose (MH: A block) and polystyrene (PS: B block). These block copolymers (BCPs) were synthesized through coupling of end-functionalized MH and PS moieties. Small-angle X-ray scattering and atomic force microscope investigations indicated self-organized cylindrical and lamellar structures in the BCP bulks and thin films with domain spacing (d) ranging from 7.65 to 10.6 nm depending on the volume fraction of MH block (ϕMH), Flory–Huggins interaction parameter (χ), and degree of polymerization (N). The BCP architecture also governed the morphology of the BCPs, e.g. the AB-type diblock copolymer (ϕMH = 0.42), the ABA-type triblock copolymer (ϕMH = 0.40), and the A2B-type miktoarm star copolymer (ϕMH = 0.45) self-organized into cylinder (d = 7.65 nm), lamellar (d = 8.41 nm), and lamellar (d = 9.21 nm) structures, respectively.

Published
2015

30. Yield stress and elasticity influence on surface tension measurements

Author

Loren Jørgensen, Hélène Delanoë-Ayari, Catherine Barentin, Marie Le Merrer, Institut universitaire des systèmes thermiques industriels (IUSTI), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Yield (engineering), Materials science, Capillary action, FOS: Physical sciences, 02 engineering and technology, General Chemistry, Mechanics, Condensed Matter - Soft Condensed Matter, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Surface energy, 010305 fluids & plasmas, Surface tension, [SPI]Engineering Sciences [physics], Flow history, 0103 physical sciences, Soft Condensed Matter (cond-mat.soft), [CHIM]Chemical Sciences, Elasticity (economics), 0210 nano-technology, Elastic modulus, ComputingMilieux_MISCELLANEOUS, Complex fluid
Abstract

We have performed surface tension measurements on carbopol gels of different concentrations and yield stresses. Our setup, based on the force exerted by a capillary bridge on two parallel plates, allows to measure an effective surface tension of the complex fluid and to investigate the influence of flow history. More precisely the effective surface tension measured after stretching the bridge is always higher than after compressing it. The difference between the two values is due to the existence of a yield stress in the fluid. The experimental observations are successfully reproduced with a simple elasto-plastic model. The shape of successive stretching-compression cycles can be described by taking into account the yield stress and the elasticity of the gel. We show that the surface tension $\gamma_{LV}$ of yield stress fluids is the mean of the effective surface tension values only if the elastic modulus is high compared to the yield stress. This work highlights that thermodynamical quantities measurements are challenged by the fluid out-of-equilibrium state implied by jamming, even at small scales where the shape of the bridge is driven by surface energy. Therefore setups allowing deformation in opposite directions are relevant for measurements on yield stress fluids., Comment: 12 pages, 16 figures in Soft Matter 2015

Published
2015

31. TiC-carbide derived carbon electrolyte adsorption study by ways of X-ray scattering analysis

Author

Patrice Simon, Patrick Rozier, Pierre-Louis Taberna, Lorie Trognko, Barbara Daffos, Nicolas Ratel-Ramond, Pierre Lecante, Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Réseau sur le stockage électrochimique de l'énergie (RS2E), Université de Picardie Jules Verne (UPJV)-Institut de Chimie du CNRS (INC)-Aix Marseille Université (AMU)-Université de Pau et des Pays de l'Adour (UPPA)-Université de Nantes (UN)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Collège de France (CdF (institution))-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Département d'Etudes des Combustibles (DEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Universidade de São Paulo (USP), Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Université de Nantes (UN)-Aix Marseille Université (AMU)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Collège de France (CdF (institution))-Université de Picardie Jules Verne (UPJV)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
Materials science, Inorganic chemistry, chemistry.chemical_element, 02 engineering and technology, Electrolyte, 010402 general chemistry, Brief Communication, 01 natural sciences, 7. Clean energy, Molecular dynamics, Adsorption, Materials Chemistry, Supercapacitors, ComputingMilieux_MISCELLANEOUS, Supercapacitor, [PHYS]Physics [physics], Renewable Energy, Sustainability and the Environment, Scattering, Nanoporous, [CHIM.MATE]Chemical Sciences/Material chemistry, X-ray scattering, 021001 nanoscience & nanotechnology, Ion adsorption, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Ionic liquids, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Chimie organique, Fuel Technology, Porous carbon, chemistry, Chemical engineering, Carbide-derived carbon, 0210 nano-technology, Carbon
Abstract

cited By 2; International audience; Understanding ion adsorption in nanoporous carbon electrodes is of great importance for designing the next-generation of high energy density electrical double-layer capacitors. In this work, X-ray scattering is used for investigating the impregnation of nanoporous carbons with electrolytes in the absence of applied potential. We are able to show that interactions between the carbon surface and electrolytes allow adsorption to take place in sub-nanopores, thus confirming experimentally for the first time the results predicted by molecular dynamic simulations.

Published
2015

32. Dynamics of Cellulose Whiskers Spatially Trapped in Agarose Hydrogels

Author

Cyrille Rochas, Erik Geissler, Redouane Borsali, Clara Ismeria Damiani Bica, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des polymères organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), Team 1 LCPO : Polymerization Catalyses & Engineering, Laboratoire de Chimie des Polymères Organiques (LCPO), and Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)

Subjects
FRICTION COEFFICIENTS, Polymers and Plastics, Whiskers, Concentration effect, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, CIRCULAR-CYLINDERS, Light scattering, Inorganic Chemistry, chemistry.chemical_compound, Nuclear magnetic resonance, Dynamic light scattering, Whisker, Materials Chemistry, PARTICLES, SYMMETRIC TOP MACROMOLECULES, Suspension (vehicle), GELS, Organic Chemistry, VISCOUS FORCE, ROTATIONAL DIFFUSION, Rotational diffusion, 021001 nanoscience & nanotechnology, LIGHT-SCATTERING, 0104 chemical sciences, Condensed Matter::Soft Condensed Matter, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Chemical physics, RIGID MATRIX, Agarose, 0210 nano-technology, POLYMER-SOLUTIONS
Abstract

International audience; The motion of cellulose whiskers trapped in agarose hydrogels is measured by depolarized dynamic light scattering (DDLS) under conditions of optical heterodyning, in which the rigid polymer network provides a static depolarized reference signal. At low concentration in free suspension, the rotational relaxation rate Theta of the whiskers is decoupled from the osmotic properties of the suspension. When incorporated inside a gel, however, as the agarose concentration increases, Theta first increases beyond that in the free suspension, reflecting a reduced amplitude of rotational fluctuations of the whiskers due to the repulsive interactions with their surroundings. At the same time, the dynamic light scattering Rayleigh ratio R-VH obtained from DDLS decreases with increasing gel concentration. At high gel concentrations, however, Theta tends to decrease due to the steric hindrance of the network. Except at the lowest whisker concentrations, Theta is governed by the same fluctuations as those associated with R-VH.

Published
2006

33. Continuous Photobleaching in Vesicles and Living Cells: A Measure of Diffusion and Compartmentation

Author

Antoine Delon, C. Souchier, Jacques Derouard, T. Biben, Yves Usson, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), RFMQ, Techniques de l'Ingénierie Médicale et de la Complexité - Informatique, Mathématiques et Applications, Grenoble - UMR 5525 (TIMC-IMAG), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Stress et Dynamique Organisation du Génome, Institut National de la Santé et de la Recherche Médicale (INSERM), and VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)

Subjects
MESH: Photons, Time Factors, Light, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Analytical chemistry, MESH: Microscopy, Fluorescence, 02 engineering and technology, Diffusion, Image Processing, Computer-Assisted, MESH: Microscopy, Confocal, Laser power scaling, MESH: Dextrans, Diffusion (business), MESH: Models, Theoretical, 0303 health sciences, Microscopy, Confocal, Photobleaching, Chemistry, Vesicle, MESH: Diffusion, Dextrans, 021001 nanoscience & nanotechnology, Fick's laws of diffusion, Fluorescence, MESH: Image Processing, Computer-Assisted, MESH: Reproducibility of Results, MESH: Permeability, MESH: Programming Languages, 0210 nano-technology, MESH: Photobleaching, Fluorescein-5-isothiocyanate, Fluorescence Recovery After Photobleaching, Green Fluorescent Proteins, Biophysics, Permeability, 03 medical and health sciences, MESH: Software, MESH: Fluorescein-5-isothiocyanate, MESH: Green Fluorescent Proteins, MESH: Computer Simulation, Spectroscopy, Imaging, Other Techniques, Humans, Computer Simulation, MESH: Biophysics, 030304 developmental biology, Fluorescence loss in photobleaching, Photons, MESH: Humans, Models, Statistical, MESH: Time Factors, Fluorescence recovery after photobleaching, Reproducibility of Results, Models, Theoretical, MESH: Light, MESH: Hela Cells, Microscopy, Fluorescence, Programming Languages, MESH: Models, Statistical, MESH: Fluorescence Recovery After Photobleaching, Software, HeLa Cells
Abstract

We present a comprehensive and analytical treatment of continuous photobleaching in a compartment, under single photon excitation. In the very short time regime (t0.1-5 s), for which the diffusion and the photobleaching balance each other. In this long time regime, the diffusion is either fast (i.e., the photobleaching probability of a molecule diffusing through the laser beam is low) so that the photobleaching rate is independent of the diffusion constant and dependent only of the laser power, or the diffusion is slow (i.e., the photobleaching probability is high) and the photobleaching rate is mainly dependent on the diffusion constant. We illustrate our theory by using giant unilamellar vesicles ranging from approximately 10 to 100 microm in diameter, loaded with molecules of various diffusion constants (from 20 to 300 microm2/s) and various photobleaching cross sections, illuminated under laser powers between 3 and 100 microW. We also demonstrated that information about compartmentation can be obtained by this method in living cells expressing enhanced green fluorescent proteins or that were loaded with small FITC-dextrans. Our quantitative approach shows that molecules freely diffusing in a cellular compartment do experience a continuous photobleaching. We provide a generic theoretical framework that should be taken into account when studying, under confocal microscopy, molecular interactions, permeability, etc.

Published
2006
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34. Purcell effect on CdSe/ZnSe quantum dots in pillar microcavities

Author

Andrea Balocchi, I. C. Robin, Régis André, S. Carayon, S. Moehl, Jean-Michel Gérard, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Nanophysique et Semiconducteurs (NPSC), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)

Subjects
Photoluminescence, Physics::Optics, 02 engineering and technology, Purcell effect, Condensed Matter::Materials Science, 020210 optoelectronics & photonics, Etching, 0202 electrical engineering, electronic engineering, information engineering, Spontaneous emission, ComputingMilieux_MISCELLANEOUS, Common emitter, [PHYS]Physics [physics], Condensed matter physics, Condensed Matter::Other, Chemistry, business.industry, Resonance, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Quantum dot, Physics::Accelerator Physics, Photonics, 0210 nano-technology, business
Abstract

The Purcell effect leads to an enhancement of the spontaneous emission in a given cavity mode for an emitter located in a small volume cavity. This effect is well explained as a consequence of Fermi's golden rule in a particular photonic environment. In this paper we show an enhancement by a factor of up to 3.4 of the spontaneous emission of CdSe/ZnSe quantum dots located in a pillar microcavity. The sample consists of a λ/2-Znse cavity sandwiched between SiO 2 /TiO 2 Bragg mirrors and is etched to provide lateral optical confinement. The present study is based on a comparison between time-resolved photoluminescence measurements for dots inserted in a pillar cavity or in a bulk ZnSe layer. The photoluminescence decay shortening is quantitatively interpreted by calculating the theoretical maximum Purcell factor expected for different cavity modes in resonance with quantum dots.

Published
2006

35. Morphology of CdSe/ZnSe quantum dots grown by MBE

Author

B. Gilles, I. C. Robin, Catherine Bougerol, Régis André, G. Van Tendeloo, B. Van Daele, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Electron Microscopy for Material Resaerch (EMAT) (EMAT), and University of Antwerp (UA)

Subjects
[PHYS]Physics [physics], 010302 applied physics, Materials science, Photoluminescence, business.industry, Atomic force microscopy, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Epitaxy, 01 natural sciences, Crystallography, Transmission electron microscopy, Quantum dot, 0103 physical sciences, Optoelectronics, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS, Single layer, Wetting layer, Molecular beam epitaxy
Abstract

The features of CdSe/ZnSe quantum dots (QDs) grown by molecular beam epitaxy at 280 °C and 240 °C are studied by transmission electron microscopy (TEM), atomic force microscopy (AFM) and photoluminescence (PL). The epitaxial structures consist of a single layer of CdSe islands sandwiched between two 40 nm thick ZnSe layers grown on a [100]-oriented GaAs substrate. UHV-AFM shows that islands are formed as a result of strain relaxation in 3 ML of CdSe pseudomorphically deposited on ZnSe. After encapsulation at 240 °C, there is no change in the QDs' morphology. On the other hand, at higher temperature, interdiffusion and segregation phenomena take place. Flat islands originating from a wetting layer and pointing to the substrate are observed, with a Cd concentration much lower in their center than at the outskirts. Both size and composition are consistent with the ∼2.35 eV PL energy that we measured. Moreover the unexpected QD morphology with Cd-rich outskirts can explain why the PL decay time depends on the samples because the confinement of holes in the QD edges makes the electron-hole overlap very sensitive to QD size. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Published
2006

36. ROTATIONAL PROPERTIES OF MICRO-SLABS DRIVEN BY LINEARLY-POLARIZED LIGHT

Author

Patrice L. Baldeck, Chantal Andraud, Isabelle Colombier, Irène Wang, Chih-Lang Lin, Marc Pierre, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie - UMR5182 (LC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Polarization plane, Physics and Astronomy (miscellaneous), [CHIM.ORGA]Chemical Sciences/Organic chemistry, business.industry, Linearly polarized light, Rotation around a fixed axis, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 021001 nanoscience & nanotechnology, Polarization (waves), 01 natural sciences, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Optics, Optical tweezers, 0103 physical sciences, Torque, 010306 general physics, 0210 nano-technology, business, Anisotropy, Laser beams
Abstract

International audience; We study the rotational motion of objects trapped in a focused laser beam (optical tweezers). Micrometer-sized flat slabs are fabricated using two-photon photopolymerization. These objects, trapped by linearly-polarized light, tend to align parallel to the polarization plane. This alignment effect is attributed to the polarization anisotropy resulting from the object shape and we present a simple electromagnetic approach to estimate the resulting optical torque. Micro-rotors of different sizes are studied experimentally. We characterize the behavior of micro-objects when the light polarization is rotated at constant speed. Our theoretical approach gives a good prediction of how the size of micro-objects affects their rotation efficiency.

Published
2005

37. Polyfluorene Based Coordination Compounds for Nonlinear Absorption

Author

Camille Girardot, Nadia Amari, Gilles Lemercier, Patrice L. Baldeck, Chantal Andraud, Laboratoire de Chimie - UMR5182 (LC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
chemistry.chemical_classification, Chloroform, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, General Chemistry, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Fluorene, Nanosecond, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Photochemistry, 01 natural sciences, Two-photon absorption, Coordination complex, Polyfluorene, chemistry.chemical_compound, 0103 physical sciences, General Materials Science, Thermal stability, 010306 general physics, 0210 nano-technology, Absorption (electromagnetic radiation)
Abstract

International audience; We report here the nonlinear absorption properties of different coordination compounds (M = Eu, Zn), based on the bifluorene system. Measurements were performed in chloroform between 450 and 650 nm for nanosecond time duration pulses. The nonlinear absorption is attributed to a three-photon absorption process involving a first two-photon absorption step followed by an excited state absorption process. The three-photon absorption efficiency of these complexes was shown to be similar to that of the bifluorene for a same concentration in bifluorene, with furthermore an excellent thermal stability.

Published
2005

38. New method to induce 2D–3D transition of strained CdSe/ZnSe layers

Author

Régis André, I. C. Robin, Jean-Michel Gérard, Le Si Dang, Henri Mariette, Serge Tatarenko, Edith Bellet-Amalric, Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Nanophysique et Semiconducteurs (NPSC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Département d'Optronique (DOPT), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA))

Subjects
[PHYS]Physics [physics], 010302 applied physics, Diffraction, High energy, Photoluminescence, Reflection high-energy electron diffraction, Materials science, business.industry, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Optics, Electron diffraction, Quantum dot, 0103 physical sciences, Optoelectronics, Amorphous selenium, 0210 nano-technology, business, Layer (electronics), ComputingMilieux_MISCELLANEOUS
Abstract

We present new growth conditions for growing high-quality CdSe/ZnSe quantum dots with photoluminescence emission measurable up to room temperature. The surface morphology is characterized in situ by Reflective High Energy Electron Diffraction (RHEED). The key point is the introduction of a new step in the growth process using amorphous selenium to induce a 2D–3D transition of a CdSe strained layer on ZnSe to form the dots. Optical characterizations by photoluminescence of CdSe/ZnSe quantum dots obtained that way, as well as X-ray diffraction results are also discussed here.

Published
2005

39. Anisotropic high-surface-area carbon aerogels

Author

David Langohr, Daniel Charrier, Françoise Ehrburger-Dolle, Patrick Achard, Sandrine Berthon-Fabry, David Djurado, Centre Énergétique et Procédés (CEP), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Aqueous solution, Nanostructure, Small-angle X-ray scattering, Supercritical drying, [SPI.NRJ]Engineering Sciences [physics]/Electric power, chemistry.chemical_element, Aerogel, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Catalysis, chemistry, Chemical engineering, Materials Chemistry, Ceramics and Composites, 0210 nano-technology, Pyrolysis, Carbon
Abstract

International audience; The subject of this paper is the investigation of the multiscale structure of a new series of carbon aerogels. These carbon aerogels are obtained by resorcinol resorcinol-formaldehyde sol-gel reactions in acetone in a single-step base catalysis (AB) or a double-step base-acid catalysis (ABA) followed by supercritical drying and pyrolysis at 1050 °C under nitrogen flow. Two complementary techniques were used: small-angle and wide-angle X-ray scattering (SAXS and WAXS) and nitrogen adsorption. Carbon aerogels AB and ABA are distinguished by a high surface area (>600m2 g-1) and by multiscale structural features that are very different from those of carbon aerogels resulting from gels prepared under the same conditions but in an aqueous solution (WB). The anisotropy observed at the mesoscale for aerogels obtained in acetone is attributed to strain occurring in the extreme operating conditions near the critical gelation concentration limit. The SAXS measurements on AB carbon aerogel reveal the presence of a high surface area with the main pore size contribution being at the nanoscale, resulting from micropores not accessible to nitrogen at -196°C. By combining SAXS and WAXS measurements, it is suggested that all carbon aerogels display structural narrow micropores. © 2004 Elsevier B.V. All rights reserved.

Published
2004

40. Angle resolved spectroscopy of polariton stimulation under non-resonant excitation in CdTe II–VI microcavity

Author

R. Romestain, Le Si Dang, Jacek Kasprzak, Maxime Richard, Régis André, Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Population, Physics::Optics, 02 engineering and technology, 01 natural sciences, Dispersion relation, 0103 physical sciences, Dispersion (optics), Polariton, General Materials Science, Spontaneous emission, Stimulated emission, 010306 general physics, education, ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], Condensed Matter::Quantum Gases, Physics, education.field_of_study, Condensed matter physics, Condensed Matter::Other, Scattering, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atomic physics, 0210 nano-technology, Excitation
Abstract

We present some experimental study of CdTe II–VI microcavity polaritons generated by strong non-resonant optical excitation. We first compare spectra of luminescence under high excitation and white light reflectivity showing that the polariton stimulation occurs in the strong coupling regime. In a second part we present a measurement of the integrated polariton emission intensity versus the excitation power: the stimulated emission exhibits an exponential behaviour which excludes a polariton/polariton quadratic collision process. In a third part we present an angle-resolved experiment showing that the stimulation peak is dispersion free while the residual spontaneous emission keeps its usual dispersion curve; we exclude a simple scattering phenomenon due to surface roughness and discuss the possibility of real space shrinkage or polariton collisions within a coherent population inspired by the theoretical work of Ciuti and co-workers.

Published
2004

41. Quantum beats between light and dark polariton states in semiconductor microcavities

Author

N. G. Galkin, Guillaume Malpuech, Régis André, Alexey Kavokin, Luis Viña, Ivan A. Shelykh, Division of Physics and Applied Physics, Nanyang Technological University [Singapour], Marie-Curie Chair of Excellence 'Polariton Devices', University of Rome II, School of Physics and Astronomy [Southampton], University of Southampton, Institut Pascal (IP), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-SIGMA Clermont (SIGMA Clermont)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and Ballet, Pascale

Subjects
Condensed Matter::Quantum Gases, Physics, Photoluminescence, Condensed matter physics, [SPI] Engineering Sciences [physics], Condensed Matter::Other, business.industry, Scattering, Physics::Optics, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Intensity (physics), [SPI]Engineering Sciences [physics], Semiconductor, Quantum beats, 0103 physical sciences, Strong coupling, Polariton, 010306 general physics, 0210 nano-technology, business, Mixing (physics)
Abstract

We observe experimentally pronounced beats of the intensity of photoluminescence from a bottleneck region of a microcavity in the strong coupling regime. These beats are extremely sensitive to the pumping intensity and vanish for the weak pumping. We show theoretically that the process of polariton-polariton scattering leading to the mixing between bright and dark polariton states is responsible for this effect. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Published
2004

42. Detuning dependence of polariton spin dynamics

Author

Régis André, Luis Viña, G. Aichmayr, M. D. Martín, Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Photoluminescence, Exciton, 02 engineering and technology, 01 natural sciences, 0103 physical sciences, Materials Chemistry, Polariton, Electrical and Electronic Engineering, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Quantum well, [PHYS]Physics [physics], Condensed Matter::Quantum Gases, Physics, Condensed matter physics, Condensed Matter::Other, Scattering, Time evolution, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 3. Good health, Electronic, Optical and Magnetic Materials, Degree of polarization, 0210 nano-technology, Excitation
Abstract

We have investigated the polariton recombination and spin dynamics in the nonlinear emission regime as a function of the cavity–exciton detuning (δ). The relaxation to K ~ 0 states, after non-resonant excitation, is governed by polariton final-state stimulated scattering. The time evolution of the degree of polarization of the photoluminescence () shows a very rich and novel behaviour, never observed in the excitonic emission in bare quantum wells. attains its maximum at a finite time after the excitation with a light pulse instead of monotonically decaying to zero as in the case of bare excitons. Furthermore, the sign of is strongly dependent on the detuning: it is positive for δ > 0 and negative for δ < 0, showing an oscillatory behaviour for δ ~ 0. The change in the sign of with the detuning is correlated with an energy splitting between the σ+- and σ−-polarized components of the photoluminescence.

Published
2004

43. New initiator for two-photon absorption induced polymerization with a microlaser at 1.06 μm

Author

Patrice L. Baldeck, Gilles Lemercier, Claude Martineau, Chantal Andraud, Irène Wang, Michel Bouriau, Laboratoire de Chimie - UMR5182 (LC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Bulk polymerization, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Conjugated system, 010402 general chemistry, Photochemistry, 01 natural sciences, Two-photon absorption, Materials Chemistry, Absorption (electromagnetic radiation), [CHIM.ORGA]Chemical Sciences/Organic chemistry, Mechanical Engineering, Metals and Alloys, [CHIM.CATA]Chemical Sciences/Catalysis, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Photopolymer, Polymerization, Mechanics of Materials, Femtosecond, Sapphire, 0210 nano-technology
Abstract

International audience; Two-photon absorption (TPA) induced polymerization is a very promising way for three-dimensional (3D) microfabrication. However, the necessity to use onerous femtosecond Ti:sapphire lasers appears as a major drawback for this technology. We present a new symmetrical conjugated ketone with terminal amino groups that can initiate TPA photopolymerization of acrylates when irradiated with an inexpensive Nd-YAG microlaser. This compound shows broad band TPA between 800 nm and 1100 nm with a cross-section of 100×10−50 cm4 s photon−1 at the photoinitiation wavelength (1.06 μm). The efficiency of this new initiator is evaluated by the determination of the threshold of absorbed energy density for polymerization.

Published
2003

44. Efficient initiators for two-photon induced polymerization in the visible range

Author

Chantal Andraud, Claude Martineau, Patrice L. Baldeck, Irène Wang, M. Bouriau, Rémi Anémian, Stéréochimie et Interactions Moléculaires (STIM), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), and École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL)

Subjects
Biphenyl, Acrylate polymer, Materials science, [CHIM.ORGA]Chemical Sciences/Organic chemistry, General Physics and Astronomy, [CHIM.CATA]Chemical Sciences/Catalysis, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Fluorene, 010402 general chemistry, 021001 nanoscience & nanotechnology, Photochemistry, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, Photopolymer, chemistry, Polymerization, Diamine, Physical and Theoretical Chemistry, 0210 nano-technology, Absorption (electromagnetic radiation), Photoinitiator
Abstract

We present two derivatives of biphenyl or fluorene symmetrically substituted, which could initiate the two-photon absorption (TPA) photopolymerization of acrylates in the visible range. Both compounds show broadband TPA between 500 and 650 nm with cross-sections of, respectively, 30 and 80×10 −50 cm 4 s photon −1 at 532 nm, the photoinitiation wavelength. Threshold energies and dynamic ranges for polymerization were measured in both cases. As expected, the fluorene derivative was slightly more efficient than the biphenyl one. Our initiators appeared to be orders of magnitude more sensitive than the commercial UV ones, commonly used for TPA photopolymerization.

Published
2002

45. General in vitro method to analyze the interactions of synthetic polymers with human antibody repertoires

Author

Avraham Halperin, Clément Nizak, Anandakumar Soshee, Nicholas D. Spencer, Stefan Zürcher, Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratory for Surface science and Technology - Department of Materials, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] [2011-2015] (LIPhy [2011-2015]), and Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)

Subjects
Antigenicity, Polymers and Plastics, Sequence analysis, Polymers, Chemistry, Pharmaceutical, Bioengineering, 02 engineering and technology, macromolecular substances, Antibodies, law.invention, Biomaterials, 03 medical and health sciences, Antigen, law, In vivo, Materials Chemistry, Humans, [SDV.IB.BIO]Life Sciences [q-bio]/Bioengineering/Biomaterials, 030304 developmental biology, 0303 health sciences, biology, Chemistry, technology, industry, and agriculture, 021001 nanoscience & nanotechnology, Binding constant, Molecular biology, In vitro, Recombinant Proteins, Biochemistry, Immunoglobulin G, Recombinant DNA, biology.protein, Antibody, 0210 nano-technology, Protein Binding
Abstract

International audience; Recent reports on the hitherto underestimated antigenicity of poly(ethylene glycol) (PEG), which is widely used for pharmaceutical applications, highlight the need for efficient testing of polymer antigenicity and for a better understanding of its molecular origins. With this goal in mind, we have used the phage-display technique to screen large, recombinant antibody repertoires of human origin in vitro for antibodies that bind poly(vinylpyrrolidone) (PVP). PVP is a neutral synthetic polymer of industrial and clinical interest that is also a well-known model antigen in animal studies, thus allowing the comparison of in vitro and in vivo responses. We have identified 44 distinct antibodies that bind specifically to PVP. Competitive binding assays show that the PVP-antibody binding constant is proportional to the polymerization degree of PVP and that specific binding is detected down to the vinylpyrrolidone (VP) monomer level. Statistical analysis of anti-PVP antibody sequences identifies an amino-acid motif that is shared by many phage-display-selected anti-PVP antibodies that are similar to a previously described natural anti-PVP antibody. This suggests a role for this motif in specific antibody/PVP interactions. Interestingly, sequence analysis also suggests that only a single antibody chain containing this shared motif is responsible for antibody binding to PVP, as confirmed upon systematic deletion of either antibody chain for 90% of selected anti-PVP antibodies. Overall, a large number of antibodies in the human repertoires we have screened bind specifically to PVP through a small number of shared amino acid motifs, and preliminary comparison points to significant correlations between the sequences of phage-display-selected anti-PVP antibodies and their natural counterparts isolated from immunized mice in previous studies. This study pioneers the use of antibody phage-display to explore the antigenicity of biotechnologically relevant polymers. It also paves the way for a fast, cost-effective, and systematic in vitro analysis, thus reducing the need for animal immunization experiments. Moreover, identifying the encoding DNA sequence of polymer-binding antibodies via phage-display enables future applications of a molecular biology approach to protein-polymer conjugation, based on protein-antibody fusion.

Published
2014

46. π-Conjugated sulfonium-based photoacid generators: an integrated molecular approach for efficient one and two-photon polymerization

Author

Jianchao Xie, Patrice L. Baldeck, Tiffanie Leclerc, Decheng Wan, Ming Jin, Davy-Louis Versace, Hong Hong, Olivier Soppera, Stephan Knopf, Arnaud Spangenberg, Hongting Pu, Jean-Pierre Malval, Olivier Poizat, School of Materials & Engineering, Shangai-Tongji University, Institut de Science des Matériaux de Mulhouse (IS2M), Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE)

Subjects
Polymers and Plastics, Sulfonium, Quantum yield, Bioengineering, 02 engineering and technology, Conjugated system, 010402 general chemistry, Photochemistry, 01 natural sciences, Biochemistry, nsfc, chemistry.chemical_compound, Polymer chemistry, medicine, Moiety, Organic Chemistry, Cationic polymerization, Vinyl ether, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry, Polymerization, national natural science foundation of china, 0210 nano-technology, Cyclohexene oxide, medicine.drug
Abstract

The cationic photoinitiating abilities of a series of 'push-pull' sulfonium-based photoacid generators (PAGs) have been investigated. In this linear π-conjugated series, a 4-N,N-diphenylaminostilbene subunit is associated with different types of sulfonium substituents, which are connected to the stilbene moiety either in the 4′ position or in the 3′ position. This para-to-meta substitution effect leads to a strong increase of the quantum yield for acid generation with a maximum value of ca. 0.5. Such a positioning effect has a strong influence on the efficiency of the S-C bond cleavage. A detailed photolysis mechanism has been proposed. In contrast to commercially available sulfonium salts, these highly reactive π-conjugated PAGs all exhibit large absorption in the visible range as well as large two-photon absorption cross-sections (δmax > 600 GM) in the near-infrared region. As a consequence, efficient one and two-photon polymerization reactions are observed at 405 nm and 800 nm, respectively, using typical monomers such as cyclohexene oxide, n-butyl vinyl ether or SU-8 photoresists. By the fabrication of well resolved two-dimensional microstructures, we finally demonstrate the potential use of these new generation PAGs in the fields of one and two-photon lithography.

Published
2014

47. DLS and SAXS investigations of organic gels and aerogels

Author

Cyrille Rochas, Patrick Achard, Anne-Marie Hecht, Nicolas Pinto, Gerard Pajonk, Sandrine Berthon, Françoise Bley, Erik Geissler, Frédéric Livet, Arnaud Rigacci, Françoise Ehrburger-Dolle, Olivier Barbieri, Centre Énergétique et Procédés (CEP), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut de chimie des surfaces et interfaces de Mulhouse (ICSIM), Ecole Nationale Supérieure de Chimie de Mulhouse-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG), Laboratoire d'Application de la Chimie à l'Environnement (LACE), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
Gelation, X ray scattering, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Catalysis, Acetone, Colloid, [SPI.ENERG]Engineering Sciences [physics]/domain_spi.energ, Dynamic light scattering, Formaldehyde, Sol-gels, Materials Chemistry, Organic chemistry, Drying, Sol-gel, Supercritical fluids, Chemistry, Small-angle X-ray scattering, Agglomeration, Percolation (solid state), Light scattering, Water, Aerogel, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Supercritical fluid, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Organic solvents, Solvent, Aging of materials, Carbon dioxide, Chemical engineering, Alcohols, Percolation, Ceramics and Composites, 0210 nano-technology
Abstract

6th International Symposium on Aerogels (ISA-6) Albuquerque, New Mexico, October 08-11, 2000; International audience; Recent investigations have shown that the structure of organic aerogels can be significantly modified by changing the precursors, the solvent and the nature of the catalyst involved in the sol-gel reaction. It is therefore highly desirable to investigate the sol-gel mechanism. For this purpose, dynamic light scattering (DLS) measurements have been performed at different stages of the reaction for base- or acid-catalyzed gelation of resorcinol-formaldehyde (RF) using water or acetone as solvents. The structure of aged gels was investigated by small-angle X-ray scattering (SAXS) and compared to that of the aerogels obtained after exchange of solvent by supercritical CO2 and drying of the aged gels. It is shown that acid-catalyzed gelation of RF in acetone can be described by percolation, which explains that this series of aerogels consists of mass fractal aggregates (Dm = 2.5). The partial collapse of this polymeric gel yielding colloidal particles in the aerogel can be attributed to deswelling in supercritical CO2. DLS indicates that gelation of RF with a base catalyst yields a colloidal gel whose structure remains practically unchanged in the aerogel, as shown by SAXS.

Published
2001

48. Formation of porous silicon: an in situ investigation with high-resolution X-ray diffraction

Author

G. Dolino, Cédric Pichat, Virginie Chamard, Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Diffraction, Materials science, Silicon, business.industry, Analytical chemistry, chemistry.chemical_element, Bragg's law, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Porous silicon, 01 natural sciences, Physics::Geophysics, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Optics, Lattice constant, chemistry, X-ray crystallography, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, business, Porous medium, Single crystal
Abstract

International audience; The single crystal property of p+ type porous silicon is used to investigate the formation mechanisms of this material by in situ X-ray diffraction. During anodisation, the diffraction peak of the porous silicon layer exhibits a lattice parameter expansion, with the usual value. For long anodisation time, a parasitic chemical dissolution leads to a regular and homogeneous decrease of lattice mismatch, also observed during pure chemical dissolution.

Published
2001

49. X-ray diffraction investigation ofn-type porous silicon

Author

G. Dolino, Virginie Chamard, Laboratoire de Spectrométrie Physique (LSP), and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)

Subjects
inorganic chemicals, Diffraction, Materials science, Silicon, education, Analytical chemistry, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, Porous silicon, 01 natural sciences, Crystal, Condensed Matter::Superconductivity, 0103 physical sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Porosity, 010302 applied physics, Doping, technology, industry, and agriculture, 021001 nanoscience & nanotechnology, Crystallography, chemistry, X-ray crystallography, Degradation (geology), 0210 nano-technology, human activities
Abstract

International audience; High resolution x-ray diffraction has been used to study the effect of doping level and illumination on the formation of n-type porous silicon. For highly doped n+ n+- type porous layers prepared in darkness, an unusual increase of the lattice mismatch with the formation time is observed. When the samples are prepared under illumination, a degradation of the crystal quality, increasing with a decrease of the material doping level, is observed. The possible origins of these effects are discussed.

Published
2001

50. Synthesis, Self-Assembly, and Thermal Caramelization of Maltoheptaose-Conjugated Polycaprolactones Leading to Spherical, Cylindrical, and Lamellar Morphologies

Author

Issei Otsuka, Redouane Borsali, Toyoji Kakuchi, Cyrille Rochas, Takuya Isono, Toshifumi Satoh, Daichi Suemasa, Hokkaido University [Sapporo, Japan], Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Hokkaido Univ, Grad Sch Engn, inconnu, and Inconnu

Subjects
Materials science, Nanostructure, Polymers and Plastics, Small-angle X-ray scattering, Organic Chemistry, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Crystallography, chemistry.chemical_compound, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Polycaprolactone, Volume fraction, Materials Chemistry, Click chemistry, Copolymer, Lamellar structure, Self-assembly, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

Three different self-assembled nanostructures, i.e., lamellar (Lam), hexagonally close-packed cylinder (Hex), and body-centered cubic (BCC), have been obtained from ABA triblock (MH-b-PCL-b-MH) and A2B star-branched copolymers ((MH)2-b-PCL) consisting of maltoheptaose (MH, as the A block) and polycaprolactone (PCL, as the B block). MH-b-PCL-b-MH and (MH)2-b-PCL were synthesized by the click reaction of the α,ω-diazido and α,α-diazido end-functionalized PCLs with N-maltoheptaosyl-3-acetamido-1-propyne in high yields. The self-assembled nanostructures of the block copolymers (BCPs) in bulk were investigated as a function of temperature by time-resolved small-angle X-ray scattering using a synchrotron light source. The SAXS analysis revealed that the obtained BCPs exhibited microphase-separated structures with the domain-spacing of 10.4–21.0 nm. MH-b-PCL-b-MH (the MH volume fraction (ϕMH) of 0.28 and 0.15) exhibited a hexagonally close-packed cylinder (Hex) at below ca. 230 °C, and the self-assembling behavi...

Published
2013

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