Journal ArticleDOI
How Heterogeneous Are Trehalose/Glycerol Cryoprotectant Mixtures? A Combined Time-Resolved Fluorescence and Computer Simulation Investigation.
Sandipa Indra,Ranjit Biswas +1 more
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TLDR
This work provides the first insight into the molecular motions and interspecies interaction in a representative Cryoprotectant mixture, and stimulates further study to investigate the interconnection between cryoprotection and dynamic heterogeneity.Abstract:
Heterogeneity and molecular motions in representative cryoprotectant mixtures made of trehalose and glycerol are investigated in the temperature range 298 ≤ T (K) ≤ 353, via time-resolved fluorescence Stokes shift and anisotropy measurements, and molecular dynamics simulations of four-point density–time correlations and H-bond relaxations. Mixtures containing 5 and 20 wt % of trehalose along with neat glycerol are studied. Viscosity coefficients for these systems lie in the range 0.30 < η (P) < 23. Measured solute (Coumarin 153) rotation and solvation times reveal a substantial departure from the hydrodynamic viscosity dependence, suggesting the strong microheterogeneous nature of these systems. Fluorescence anisotropy decays are highly nonexponential, reflecting a non-Markovian character of the medium friction. A complete missing of the Stokes shift dynamics in these systems at 298 K but partial detection of it at other higher temperatures (shift magnitude being ∼400–600 cm–1) indicates rigid solute envi...read more
Citations
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How do glycerol and dimethyl sulphoxide affect local tetrahedral structure of water around a nonpolar solute at low temperature? Importance of preferential interaction.
TL;DR: The comparative effect of glycerol and DMSO on the orientational order of water around a nonpolar solute at -5 °C is investigated through all-atom molecular dynamics simulation and a plausible mechanism for these contrasting roles of these cosolvents is put forward.
Journal ArticleDOI
Dielectric relaxation in acetamide + urea deep eutectics and neat molten urea: Origin of time scales via temperature dependent measurements and computer simulations.
TL;DR: The temporal heterogeneity aspects of these media have been investigated by examining the simulated particle motion characteristics and substantiated by estimating the dynamically correlated time scales and length-scales through simulations of four-point susceptibilities and density correlations.
Journal ArticleDOI
Interaction and Dynamics in a Fully Biodegradable Glucose-Containing Naturally Abundant Deep Eutectic Solvent: Temperature-Dependent Time-Resolved Fluorescence Measurements
TL;DR: A new room temperature deep eutectic solvent composed of glucose, urea and water has been prepared, and its relaxation dynamics explored via temperature dependent time-resolved fluorescence measurements employing hydrophilic and hydrophobic solute probes, indicating pronounced temporal heterogeneity in the relaxation dynamics.
Journal ArticleDOI
Breakdown of the Stokes-Einstein Relation in Supercooled Water/Methanol Binary Mixtures: Explanation Using the Translational Jump-Diffusion Approach.
TL;DR: Molecular insight is provided into the SE breakdown for the supercooled water/methanol binary mixture, as found in the experiment, where it is understood that the jump-diffusion is the key responsible factor for theSE breakdown.
Journal ArticleDOI
Importance of Solvents’ Translational–Rotational Coupling for Translational Jump of a Small Hydrophobic Solute in Supercooled Water
TL;DR: It is inferred that the large-amplitude translational jump of the nonpolar solute probably stems from the spatiotemporal heterogeneity of supercooled water, at temperatures above the melting point, since the translational and orientational prearrangements become somewhat independent of each other.
References
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Numerical Integration of the Cartesian Equations of Motion of a System with Constraints: Molecular Dynamics of n-Alkanes
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A unified formulation of the constant temperature molecular dynamics methods
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Journal ArticleDOI
Development and Testing of the OPLS All-Atom Force Field on Conformational Energetics and Properties of Organic Liquids
TL;DR: In this article, the parametrization and testing of the OPLS all-atom force field for organic molecules and peptides are described, and the parameters for both torsional and non-bonded energy properties have been derived, while the bond stretching and angle bending parameters have been adopted mostly from the AMBER force field.
Journal ArticleDOI
Structure and Dynamics of the TIP3P, SPC, and SPC/E Water Models at 298 K
Pekka Mark and,Lennart Nilsson +1 more
TL;DR: In this paper, the effects of velocity rescaling on the self-diffusion coefficient D and radial distribution functions, gOO, gOH, and gHH for all five water models were determined and compared to experimental data.
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