Molecular clustering and percolation characteristics near the glass transition in aqueous trehalose and choline dihydrogen phosphate solutions

2018 ◽  
Vol 20 (32) ◽  
pp. 20899-20909
Author(s):  
Nikita Nikulsin ◽  
E. R. Azhagiya Singam ◽  
Gloria Elliott ◽  
Donald Jacobs
Keyword(s):  
Molecular Structure ◽  
Molecular Dynamics ◽  
Glass Transition ◽  
Dihydrogen Phosphate ◽  
Stoichiometric Ratio ◽  
Ternary Solutions ◽  
Dynamics Simulations ◽  
Molecular Clustering ◽  
Phosphate Solutions ◽  
Spatial And Temporal Characteristics

Spatial and temporal characteristics of molecular structure in ternary solutions of trehalose and choline dihydrogen phosphate (CDHP) are studied using molecular dynamics simulations at 300 K for a range of solute concentrations with a 2 : 1 stoichiometric ratio of trehalose to CDHP.

Molecular-Dynamics Analysis of the Structural Properties of Silica during Cooling

2008 ◽  
Vol 139 ◽  
pp. 101-106 ◽  
Author(s):  
Byoung Min Lee ◽  
Shinji Munetoh ◽  
Teruaki Motooka ◽  
Yeo Wan Yun ◽  
Kyu Mann Lee
Keyword(s):  
Molecular Dynamics ◽  
Glass Transition ◽  
Transition Temperature ◽  
Structural Properties ◽  
Diffusion Coefficients ◽  
The Self ◽  
Dynamics Analysis ◽  
Self Diffusion ◽  
Dynamics Simulations ◽  
Potential Parameters

The structural properties of SiO2 liquid during cooling have been investigated by molecular dynamics simulations. The interatomic forces acting on the particles are calculated by the modified Tersoff potential parameters. The glass transition temperature and structural properties of the resulting SiO2 system at various temperatures have been investigated. The fivefold coordinations of Si and threefold coordinations of O atoms were observed, and the coordination defects of system decrease with decreasing temperature up to 17 % at 300 K. The self-diffusion coefficients for Si and O atoms drop to almost zero below 3000 K. The structures were distorted at high temperatures, but very stable atomic network persisted up to high temperature in the liquid state.

scholarly journals Evidence for Glass Behavior in Amorphous Carbon

2020 ◽  
Vol 6 (3) ◽  
pp. 50 ◽  
Author(s):  
Steven Best ◽  
Jake B. Wasley ◽  
Carla de Tomas ◽  
Alireza Aghajamali ◽  
Irene Suarez-Martinez ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Diffusion Coefficient ◽  
Glass Transition ◽  
Transition Temperature ◽  
Amorphous Carbon ◽  
The Self ◽  
Self Diffusion ◽  
Dynamics Simulations ◽  
Self Diffusion Coefficient ◽  
Glass Behavior

Amorphous carbons are disordered carbons with densities of circa 1.9–3.1 g/cc and a mixture of sp2 and sp3 hybridization. Using molecular dynamics simulations, we simulate diffusion in amorphous carbons at different densities and temperatures to investigate the transition between amorphous carbon and the liquid state. Arrhenius plots of the self-diffusion coefficient clearly demonstrate that there is a glass transition rather than a melting point. We consider five common carbon potentials (Tersoff, REBO-II, AIREBO, ReaxFF and EDIP) and all exhibit a glass transition. Although the glass-transition temperature (Tg) is not significantly affected by density, the choice of potential can vary Tg by up to 40%. Our results suggest that amorphous carbon should be interpreted as a glass rather than a solid.

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