scholarly journals Triphase Separation of a Ternary Symmetric Highly Viscous Mixture

Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 936
Author(s):  
Andrea Lamorgese ◽  
Roberto Mauri
Keyword(s):  
Phase Separation ◽  
Pair Correlation ◽  
Liquid Mixtures ◽  
Phase Region ◽  
Diffuse Interface ◽  
Integral Scale ◽  
Integral Scales ◽  
Gibbs Energy Of Mixing ◽  
The One ◽  
Three Phases

We discuss numerical results of diffusion-driven separation into three phases of a symmetric, three-component highly viscous liquid mixture after an instantaneous quench from the one-phase region into an unstable location within the tie triangle of its phase diagram. Our theoretical approach follows a diffuse-interface model of partially miscible ternary liquid mixtures that incorporates the one-parameter Margules correlation as a submodel for the enthalpic (so-called excess) component of the Gibbs energy of mixing, while its nonlocal part is represented based on a square-gradient (Cahn–Hilliard-type) modeling assumption. The governing equations for this phase-field ternary mixture model are simulated in 3D, showing the segregation kinetics in terms of basic segregation statistics, such as the integral scale of the pair-correlation function and the separation depth for each component. Based on the temporal evolution of the integral scales, phase separation takes place via the simultaneous growth of three phases up until a symmetry-breaking event after which one component continues to separate quickly, while phase separation for the other two seems to be delayed. However, inspection of the separation depths reveals that there can be no symmetry among the three components at any instant in time during a triphase segregation process.

Phase Separation of a Binary Liquid System in Controlled-Pore Glass

2003 ◽  
Vol 790 ◽  
Author(s):  
S. Schemmel ◽  
D. Akcakayiran ◽  
G. Rother ◽  
A. Brulet ◽  
B. Farago ◽  
...  
Keyword(s):  
Phase Separation ◽  
Spin Echo ◽  
Effective Diffusion ◽  
Liquid Mixtures ◽  
Isobutyric Acid ◽  
Liquid System ◽  
Phase Region ◽  
Neutron Spin ◽  
Binary Liquid ◽  
Order Of Magnitude

ABSTRACTThe phase separation behaviour and the dynamics of concentration fluctuations of binary liquid mixtures are strongly influenced by confinement effects. We have investigated this confinement effect for the binary system isobutyric acid iBA + D2O imbibed into a mesoporous silica glass (CPG-10). The dynamics of the mixture are studied in the one-phase region as well as in the phase-separated state by means of neutron spin echo spectroscopy (NSE). Moreover, the averaged structures of the liquid are explored by means of small angle neutron scattering (SANS) leading to a length scale 4 < ξ < 9 nm for the fluctuations. The associated effective diffusion coefficient Deff as obtained for NSE is found to decrease with temperature ny nearly one order of magnitude in the temperature range from 75°C to 25°C.

Consolute Critical Phenomena in Dilute Silica Gel

1992 ◽  
Vol 290 ◽  
Author(s):  
B. J. Frisken ◽  
Fabio Ferri ◽  
David S. Cannell
Keyword(s):  
Correlation Function ◽  
Critical Phenomena ◽  
Liquid Mixtures ◽  
Phase Region ◽  
Silica Network ◽  
Exponential Form ◽  
Pure System ◽  
Consolute Point ◽  
Exponential Correlation Function ◽  
The One

AbstractThe effect of even dilute silica networks on the critical phenomena of binary liquid mixtures is profound. The network preferentially adsorbs one component, preventing a portion of the mixture from participating in critical fluctuations. Fluctuations in the remaining mixture are found to decay with a non-exponential correlation function near the consolute point. A correlation function consisting of the sum of an exponential decay and a non-exponential term of either an activated or stretched exponential form fits the data well. In the presence of the silica network, the mixtures are observed to phase separate near the critical temperature of the pure system, but while still in the one-phase region of the pure system.

SHEAR-INDUCED MIXING IN POLYMER BLENDS

1994 ◽  
Vol 08 (19) ◽  
pp. 1143-1161 ◽  
Author(s):  
ERIK K. HOBBIE ◽  
ALAN I. NAKATANI ◽  
CHARLES C. HAN
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Polymer Blends ◽  
Large Scale ◽  
Mean Field ◽  
Phase Region ◽  
Theoretical Predictions ◽  
The One ◽  
Composition Fluctuations ◽  
Good Agreement

The effect of shear flow on phase separation in critical polymer blends is reviewed. For a low-molecular-weight blend, the response is in good agreement with the theoretical predictions of Onuki and Kawasaki. The break-up of large-scale critical fluctuations by the flow leads to a drop in the temperature T c at which phase separation begins. For a high-molecular-weight blend, the data suggest that the mode-coupling contribution to the decay rate of composition fluctuations is significant in both the miscible and immiscible phases. No shear-induced shift in T c is apparent at any temperature in the one-phase region away from the equilibrium critical point, consistent with mean-field statics.

General Trend of Negative Transference Number in Li Salt/Ionic Liquid Mixtures

2019 ◽  
Author(s):  
Nicola Molinari ◽  
Jonathan P. Mailoa ◽  
Boris Kozinsky
Keyword(s):  
Ionic Liquid ◽  
Transference Number ◽  
Liquid Mixtures ◽  
Single Linkage ◽  
Self Diffusion ◽  
Wide Range ◽  
Single Linkage Cluster ◽  
Concentrated Solution ◽  
The One ◽  
Dynamics Simulations

We show that strong cation-anion interactions in a wide range of lithium-salt/ionic liquid mixtures result in a negative lithium transference number, using molecular dynamics simulations and rigorous concentrated solution theory. This behavior fundamentally deviates from the one obtained using self-diffusion coefficient analysis and agrees well with experimental electrophoretic NMR measurements, which accounts for ion correlations. We extend these findings to several ionic liquid compositions. We investigate the degree of spatial ionic coordination employing single-linkage cluster analysis, unveiling asymmetrical anion-cation clusters. Additionally, we formulate a way to compute the effective lithium charge that corresponds to and agrees well with electrophoretic measurements and show that lithium effectively carries a negative charge in a remarkably wide range of chemistries and concentrations. The generality of our observation has significant implications for the energy storage community, emphasizing the need to reconsider the potential of these systems as next generation battery electrolytes.<br>

scholarly journals X-Ray and Neutron Diffraction of Amorphous Nickel-Zirconium-Alloys as Prepared in Different Ways

1991 ◽  
Vol 46 (6) ◽  
pp. 491-498 ◽  
Author(s):  
L. Schultz ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Short Range ◽  
Melt Spinning ◽  
Short Range Order ◽  
Pair Correlation ◽  
Zirconium Alloys ◽  
X Ray ◽  
Coordination Numbers ◽  
Structure Factors ◽  
The One

AbstractThe structure of amorphous NiχZr100-χ-alloys (Χ= 30, 31, 34, 63.7, and 65), which were produced by melt spinning (MS), mechanical alloying (MA), and sputtering (SP) was studied by X-ray- and neutron diffraction yielding structure factors, pair correlation functions, coordination numbers, atomic distances, and Warren-Cowley chemical short range order parameters. The atomic arrangement within the first coordination sphere is independent of the method of preparation while in the second and higher spheres it differs between the MS- and the MA-alloys on the one side and the SP-specimens on the other side. Thus one understands that some physical properties of the different specimens differ

scholarly journals The non-equilibrium region of grid-generated decaying turbulence

2014 ◽  
Vol 744 ◽  
pp. 5-37 ◽  
Author(s):  
P. C. Valente ◽  
J. C. Vassilicos
Keyword(s):  
Turbulent Flows ◽  
Integral Scale ◽  
Dissipation Coefficient ◽  
Integral Scales ◽  
Usual Equilibrium ◽  
Decaying Turbulence ◽  
Equilibrium Region ◽  
Non Equilibrium

AbstractThe previously reported non-equilibrium dissipation law is investigated in turbulent flows generated by various regular and fractal square grids. The flows are documented in terms of various turbulent profiles which reveal their differences. In spite of significant inhomogeneity and anisotropy differences, the new non-equilibrium dissipation law is observed in all of these flows. Various transverse and longitudinal integral scales are measured and used to define the dissipation coefficient $C_{\varepsilon }$. It is found that the new non-equilibrium dissipation law is not an artefact of a particular choice of the integral scale and that the usual equilibrium dissipation law can actually coexist with the non-equilibrium law in different regions of the same flow.

Specific heat of the liquid mixtures of neon and hydrogen isotopes in the phase-separation region

Physica ◽  
1970 ◽  
Vol 50 (1) ◽  
pp. 93-124 ◽  
Author(s):  
J.P. Brouwer ◽  
C.J.N. Van Den Meijdenberg ◽  
J.J.M. Beenakker
Keyword(s):  
Phase Separation ◽  
Specific Heat ◽  
Hydrogen Isotopes ◽  
Liquid Mixtures ◽  
Separation Region ◽  
Phase Separation Region
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