A5063370611- Material Dynamics and Properties
- NMR spectroscopy and applications
- Nanopore and Nanochannel Transport Studies
- Spectroscopy and Quantum Chemical Studies
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- Advanced Battery Materials and Technologies
- Protein Structure and Dynamics
- Ionic liquids properties and applications
- Quantum, superfluid, helium dynamics
- Fuel Cells and Related Materials
- Solid-state spectroscopy and crystallography
- Soil and Unsaturated Flow
- Phase Equilibria and Thermodynamics
- High-pressure geophysics and materials
- Enzyme Structure and Function
- Advanced Condensed Matter Physics
- Theoretical and Computational Physics
- Anodic Oxide Films and Nanostructures
- Electrostatics and Colloid Interactions
- Nuclear reactor physics and engineering
- Hydrocarbon exploration and reservoir analysis
- Liquid Crystal Research Advancements
- Advancements in Solid Oxide Fuel Cells
- Clay minerals and soil interactions
Laboratoire Léon Brillouin
2016-2025
CEA Paris-Saclay
2016-2025
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016-2025
Chimie Moléculaire, Macromoléculaire, Matériaux
2016-2025
Université Paris-Saclay
2016-2024
Centre National de la Recherche Scientifique
2013-2024
CEA Paris-Saclay - Etablissement de Saclay
2014-2024
Sciences et Ingénierie de la Matière Molle
2016-2022
Institut Laue-Langevin
2021
Edinburgh College
2018
Quasi-one-dimensional water encapsulated inside single-walled carbon nanotubes, here referred to as nanotube water, was studied by neutron scattering. The results reveal an anomalously soft dynamics characterized pliable hydrogen bonds, anharmonic intermolecular potentials, and large-amplitude motions in water. Molecular simulations consistently describe the observed phenomena propose structure of which comprises a square-ice sheet wrapped into cylinder interior molecules chainlike configuration.
Recent neutron scattering studies of single-particle dynamics water molecules contained in micropores Vycor glass are presented. Results incoherent quasielastic and inelastic spectra from the confined ${\mathrm{H}}_{2}$O analyzed to obtain elastic structure factor, short time self-diffusion constants, residence for jump diffusion, rotational relaxation time, proton density states as functions coverage temperature. Implication degree confinement slowing down motions discussed light available...
We have made a high-resolution quasielastic incoherent neutron scattering (QENS) study of the translational dynamics supercooled water contained in micropores Vycor glass at different hydration levels. QENS spectra from confined ${\mathrm{H}}_{2}\mathrm{O}$ are analyzed terms \ensuremath{\alpha}-relaxation predicted by mode-coupling theory liquids and recent computer molecular-dynamics simulation extended simple point charge model water. verify that stretched exponential relaxation...
At ambient pressure, bulk liquid water shows an anomalous increase of thermodynamic quantities and apparent divergences dynamic properties on approaching a temperature Ts 228 K. normal supercooled spontaneously freezes below the homogeneous nucleation temperature, TH = 235 Upon heating, two forms Amorphous Solid Water (ASW), LDA (Low Density Ice) HDA (High Ice), crystallise above TX 150 As consequence, up to now no experiment has been able explore in this very interesting range between We...
Water is essential for the stability and function of biological macromolecules. High-resolution quasi-elastic neutron scattering studies translational dynamics water molecules on surface a deuteriated protein are presented. The spectra from interfacial H2O analysed by confined diffusion model to obtain elastic incoherent structure factor (EISF), short-time self-diffusion constant (D) residence time, τ0, as functions coverage temperature. combined effects hydration level temperature...
We present a quasi-elastic neutron scattering study of water dynamics confined in model clay system, synthetic hectorite with Na+ compensating counterions. As shown by adsorption gravimetry and neutron/X-ray diffraction, the system has, unlike its natural counterparts, very well-defined swelling characteristics, clear appearance monohydrated bihydrated state. This simplifies to great extent analysis interpretation. Initially, microscopic relaxation times as well long-range self-diffusion...
The impact of pore size and surface composition on water dynamics confined in highly ordered porous silica material (MCM-41) was investigated using neutron scattering for correlation times the picosecond range. Samples were synthesized by hydrothermal route grafted via hydrolytic sol–gel method to obtain wall surfaces with Si–OH, Al–OH, or Zr–OH terminations sizes from 2 2.7 nm. samples characterized after grafting nitrogen adsorption–desorption isotherms small-angle X-ray scattering. At...
Water confined within carbon nanotubes (CNT) exhibits tremendous enhanced transport properties. Here, we extend this result to ionic liquids (IL) in vertically aligned CNT membranes. Under confinement, the IL self-diffusion coefficient is increased by a factor 3 compared its bulk reference. This could lead high power battery separators.
We have investigated the dynamics of liquid water confined in mesostructured porous silica (MCM-41) and periodic mesoporous organosilicas (PMOs) by incoherent quasielastic neutron scattering experiments. The effect tuning water/surface interaction from hydrophilic to more hydrophobic on mobility, while keeping pore size range 3.5-4.1 nm, was assessed comparative study three PMOs comprising different organic bridging units purely siliceous MCM-41 case. An extended dynamical achieved combining...
Abstract The dynamics of water in porous charged media (montmorillonite clay) is investigated on the picosecond-timescale by quasi-elastic neutron scattering (time-of-flight (TOF) and spin echo (NSE) techniques) classical molecular simulations. Correspondence discussed not only terms integrated quantities such as diffusion coefficients but also more directly level intermediate functions. Both simulated experimental are order 5–10 × 10 −10 m 2 s −1 . Closer analysis suggests that, unlike...
The existence of a protein dynamic transition around 220 K is widely known and the central role hydration shell now largely recognized as driving force for this transition. In paper, we propose mechanism, at molecular level, contribution water. particular, identify key importance rotational motion water source configurational entropy triggering (i) crossover (the so-called transition) but also (ii) much less intense scarcely reported crossover, associated to calorimetric glass transition, 150 K.
The fundamental role of hydration water (also called interfacial water) is widely recognized in protein flexibility, especially the existence so-called "dynamical transition" at around 220 K. In present study, we take advantage perdeuterated C-phycocyanin (CPC) and elastic incoherent neutron scattering (EINS) to distinguish between dynamics dynamics. Powders hydrogenated (hCPC) (dCPC) CPC have been hydrated, respectively, with D(2)O or H(2)O measured by EINS separately probe (hCPC/D(2)O)...
If protein structure and function changes upon adsorption are well documented, modification of adsorbed dynamics remains a blind spot, despite its importance in biological processes. The metmyoglobin on silica surface was studied by isotherm measurements, microcalorimetry, circular dichroı̈sm, UV–visible spectroscopy to determine the thermodynamic parameters consequent modifications. mean square displacement vibrational densities states were measured elastic inelastic neutron scattering...
The influence of structural disorder on the thermal transport in colusite $\mathrm{C}{\mathrm{u}}_{26}{\mathrm{V}}_{2}\mathrm{S}{\mathrm{n}}_{6}{\mathrm{S}}_{32}$ has been investigated by means low-temperature conductivity and specific heat measurements (2--300 K), $^{119}\mathrm{Sn}$ M\"ossbauer spectroscopy temperature-dependent powder inelastic neutron scattering (INS). Variations high-temperature synthesis conditions act as a key parameter for tuning degree compounds. Intriguingly, we...
High-Entropy Alloys (HEAs) are a new family of crystalline random alloys with four or more elements in simple unit cell, at the forefront materials research for their exceptional mechanical properties. Their strong chemical disorder leads to mass and force-constant fluctuations which expected strongly reduce phonon lifetime, responsible thermal transport, similarly glasses. Still, long range order would associate HEAs crystals complex disordered cell. These two families materials, however,...
Intermediate scattering functions for density fluctuation in D2O contained pores of a Vycor glass have been measured using an improved neutron spin-echo spectrometer at two supercooled temperatures. The measurements cover the time range from 1 to 2300 ps with Q spanning first diffraction peak water. correlation can be fitted stretched exponential relaxation function Q-dependent amplitude. Both stretch exponent and approximately value corresponding peak, confirming validity mode coupling idea
When probed at the macroscopic scale, Ionic Liquids (ILs) behave as highly dissociated (i.e. strong) electrolytes while, molecular they show clear characteristics of weak ionic solutions. The multi-scale analysis we report in this paper reconciles these apparently odds behaviors. We investigate by quasi-elastic neutron scattering (QENS) and spin-echo (NSE), nanometer/nanosecond dynamics OMIM-BF4, an imidazolium-based IL showing strong nanostructuration. also probe same on microscopic (μm ms)...
Slow down of ionic liquid dynamics when confined in a biopolymer silica host network and segregation lithium at the interface.
Ionic Liquids (ILs) are a specific class of molecular electrolytes characterized by the total absence co-solvent. Due to their remarkable chemical and electrochemical stability, they prime candidates for development safe sustainable energy storage systems. The competition between electrostatic van der Waals interactions leads property original pure liquids: self-organize in fluctuating nanometric aggregates. So far, this transient structuration has escaped direct clear-cut experimental...