Here we report high-precision measurements of structural relaxation dynamics in the glass transition range at the intermediate and short length scale for a strong sodium silicate glass during long annealing times. We evidence for the first time the heterogeneous dynamics at the intermediate range order by probing the acoustic longitudinal frequency in the GHz region by Brillouin light scattering spectroscopy. Or, from in-situ Raman measurements, we show that relaxation is indeed homogeneous at the interatomic length scale. Our results show that the dynamics at the intermediate range order contains two distinct relaxation time scales, a fast and a slow component, differing by about a 10-fold factor below Tg and approaching to one another past the glass transition. The slow relaxation time agrees with the shear relaxation time, proving that Si-O bond breaking constitutes the primary control of structural relaxation at the intermediate range order.
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http://dx.doi.org/10.1021/jp401112s | DOI Listing |
Food Chem
December 2024
INRAE, OPAALE, 35044 Rennes, France. Electronic address:
Understanding lipid digestion is crucial for promoting human health. Traditional methods for studying lipolysis face challenges in sample representativeness and pre-treatment, and cannot measure real-time lipolysis in vivo. Thus, non-invasive techniques like magnetic resonance imaging (MRI) need to be developed.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Department of Chemistry, University of California, Berkeley, California 94720, United States.
ConspectusThe electronic properties of atomically thin van der Waals (vdW) materials can be precisely manipulated by vertically stacking them with a controlled offset (for example, a rotational offset─i.e., twist─between the layers, or a small difference in lattice constant) to generate moiré superlattices.
View Article and Find Full Text PDFNanoscale
January 2025
Physics and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium.
Many applications of nanocrystals rely on their use in light detection and emission. In recent years, nanocrystals with more relaxed carrier confinement, including so-called 'bulk' and 2D implementations, have made their stake. In such systems, the charge carriers generated after (photo-)excitation are spread over a semi-continuous density of states, behaviour controlled by the carrier temperature .
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Department of Computational Sciences, School of Basic Sciences, Central University of Punjab, Bathinda 151401, India.
The effect of confinement on the tetrahedral ordering of liquid water plays a vital role in controlling their microscopic structure and dynamics as well as their spectroscopic properties. In this article, we have performed the classical molecular dynamics simulations of four different CTAB/water/chloroform reverse micelles with varied water content to study how the tetrahedral ordering of nanoscale water inside reverse micellar confinement influences the microscopic dynamics and the structural relaxation of water···water hydrogen bonds and its impact on the low-frequency intermolecular vibrational bands. We have noticed from the results obtained from simulated trajectories the lowering trends of tetrahedral ordering of water pools in reverse micellar confinements as we move from bulk to confined and strictly confined environments.
View Article and Find Full Text PDFFront Child Adolesc Psychiatry
July 2024
Counselling Psychology, Faculty of Education, University of Ottawa, Ottawa, ON, Canada.
Introduction: Some targets of relational peer victimization become depressed because of their poor treatment. These associations are well documented in youth but are rarely studied in adults.
Methods: The longitudinal pathways between relational peer victimization (being excluded, stonewalled, etc.
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