Glass polymorphism in glycerol-water mixtures: I. A computer simulation study.

We perform out-of-equilibrium molecular dynamics (MD) simulations of water-glycerol mixtures in the glass state. Specifically, we study the transformations between low-density (LDA) and high-density amorphous (HDA) forms of these mixtures induced by compression/decompression at constant temperature. Our MD simulations reproduce qualitatively the density changes observed in experiments.

Glass polymorphism in glycerol-water mixtures: II. Experimental studies.

We report a detailed experimental study of (i) pressure-induced transformations in glycerol-water mixtures at T = 77 K and P = 0-1.8 GPa, and (ii) heating-induced transformations of glycerol-water mixtures recovered at 1 atm and T = 77 K. Our samples are prepared by cooling the solutions at ambient pressure at various cooling rates (100 K s(-1)-10 K h(-1)) and for the whole range of glycerol mole fractions, χ(g).

Pressure-induced transformations in glassy water: A computer simulation study using the TIP4P/2005 model.

We study the pressure-induced transformations between low-density amorphous (LDA) and high-density amorphous (HDA) ice by performing out-of-equilibrium molecular dynamics (MD) simulations. We employ the TIP4P/2005 water model and show that this model reproduces qualitatively the LDA-HDA transformations observed experimentally. Specifically, the TIP4P/2005 model reproduces remarkably well the (i) structure (OO, OH, and HH radial distribution functions) and (ii) densities of LDA and HDA at P = 0.

Effects of temperature on the thermodynamic and dynamical properties of glycerol-water mixtures: a computer simulation study of three different force fields.

Glycerol-water solutions are relevant in technological and scientific applications, such as in the preservation of biomolecules and tissues at low temperatures. We perform molecular dynamics simulations of glycerol-water mixtures with glycerol molar fractions of χg = 0-100% at P = 0.1 MPa and T = 210-460 K.

Effects of temperature on the properties of glycerol: a computer simulation study of five different force fields.

We perform molecular dynamics simulations of glycerol (propane-1,2,3-triol) at normal pressure and a wide range of temperatures (300-460 K) and study the sensitivity of simulation results to the force field (FF) considered. We employ five commonly used FFs: (i) AMBER, (ii) CHARMM22, and (iii) three versions of the OPLS-AA FF (OPLS1, OPLS2, and OPLS3). We study thermodynamic (density ρ(T), thermal expansion coefficient αP(T), isobaric specific heat cP(T)), dynamic (diffusion coefficient D(T)), as well as structural properties (molecular conformations and hydrogen-bond statistics).