Effect of Nanoscale rods on the Kinetics of Phase-Separating Multi-Component Fluids

2004 ◽  
Vol 856 ◽  
Author(s):  
Michael J.A. Hore ◽  
Mohamed Laradji
Keyword(s):  
Phase Separation ◽  
Large Scale ◽  
Volume Fraction ◽  
Three Dimensions ◽  
Domain Growth ◽  
Slowing Down ◽  
Nanoparticles Volume Fraction ◽  
Scale Particle ◽  
Dynamics Simulations ◽  
Kinetics Of

ABSTRACTUsing large scale particle dynamics simulations, we investigated the effect of nanoscale rods on the dynamics of phase separation dynamics of two-component fluids in three dimensions. We found that when the nanoparticles interact more attractively with one of the two segregating component, they lead to a reduction of the rate of domain growth, and that this decrease is intensified as the nanoparticles volume fraction is increased. Furthermore, our results show that nanorods are much more effective in slowing down the kinetics than nanosphres. The dramatic effect of nanorods on the dynamics of phase separation of multi-component fluids, as opposed to nanospheres, implies that they may be used as an efficacious emulsifying agent of multi-component polymer blends.

Manipulating the kinetics and mechanism of phase separation in dynamically asymmetric LCST blends by nanoparticles

2015 ◽  
Vol 17 (41) ◽  
pp. 27446-27461 ◽  
Author(s):  
J. Khademzadeh Yeganeh ◽  
F. Goharpey ◽  
E. Moghimi ◽  
G. Petekidis ◽  
R. Foudazi
Keyword(s):  
Phase Separation ◽  
Kinetics And Mechanism ◽  
Domain Growth ◽  
Slowing Down ◽  
Kinetics Of

The addition of nanoparticles in dynamically asymmetric LCST blends is used to induce the preferred phase-separating morphology by tuning the dynamic asymmetry, and to control the kinetics of phase separation by slowing down (or even arresting) the domain growth.

Snowflakes in the atmospheric surface layer: observation of particle–turbulence dynamics

2017 ◽  
Vol 814 ◽  
pp. 592-613 ◽  
Author(s):  
Andras Nemes ◽  
Teja Dasari ◽  
Jiarong Hong ◽  
Michele Guala ◽  
Filippo Coletti
Keyword(s):  
Large Scale ◽  
Isotropic Turbulence ◽  
Volume Fraction ◽  
Response Times ◽  
Field Measurements ◽  
Stokes Number ◽  
Inertial Particles ◽  
Natural Setting ◽  
Scale Particle ◽  
Particle Imaging

We report on optical field measurements of snow settling in atmospheric turbulence at $Re_{\unicode[STIX]{x1D706}}=940$. It is found that the snowflakes exhibit hallmark features of inertial particles in turbulence. The snow motion is analysed in both Eulerian and Lagrangian frameworks by large-scale particle imaging, while sonic anemometry is used to characterize the flow field. Additionally, the snowflake size and morphology are assessed by digital in-line holography. The low volume fraction and mass loading imply a one-way interaction with the turbulent air. Acceleration probability density functions show wide exponential tails consistent with laboratory and numerical studies of homogeneous isotropic turbulence. Invoking the assumption that the particle acceleration has a stronger dependence on the Stokes number than on the specific features of the turbulence (e.g. precise Reynolds number and large-scale anisotropy), we make inferences on the snowflakes’ aerodynamic response time. In particular, we observe that their acceleration distribution is consistent with that of particles of Stokes number in the range $St=0.1{-}0.4$ based on the Kolmogorov time scale. The still-air terminal velocities estimated for the resulting range of aerodynamic response times are significantly smaller than the measured snow particle fall speed. This is interpreted as a manifestation of settling enhancement by turbulence, which is observed here for the first time in a natural setting.

Three-Dimensional Simulations of Phase Separation in Model Binary Alloy Systems with Elasticity

1997 ◽  
Vol 481 ◽  
Author(s):  
D. Orlikowski ◽  
C. Sagui ◽  
A. S. Somoza ◽  
C. Roland
Keyword(s):  
Phase Separation ◽  
Binary Alloy ◽  
Large Scale ◽  
Three Dimensional ◽  
Elastic Field ◽  
Dimensional System ◽  
Elastic Fields ◽  
Slowing Down ◽  
Three Dimensional Simulations ◽  
Alloy Systems

ABSTRACTWe report on large-scale three-dimensional simulations of phase separation in model binary alloy systems in the presence of elastic fields. The elastic field has several important effects on the morphology of the system: the ordered domains are subject to shape transformations, and spatial ordering. In contrast to two-dimensional system, no significant slowing down in the growth is observed. There is also no evidence of any “reverse coarsening” of the domains.

scholarly journals Periodic Boundary Conditions for Dislocation Dynamics Simulations in Three Dimensions

2000 ◽  
Vol 653 ◽  
Author(s):  
Vasily V. Bulatov ◽  
Moon Rhee ◽  
Wei Cai
Keyword(s):  
Boundary Conditions ◽  
Large Scale ◽  
Periodic Boundary ◽  
Periodic Boundary Conditions ◽  
Dislocation Dynamics ◽  
Three Dimensions ◽  
Translational Invariance ◽  
Timing Data ◽  
Dynamics Simulations ◽  
Consistent Treatment

AbstractThis article presents an implementation of periodic boundary conditions (PBC) for Dislocation Dynamics (DD) simulations in three dimensions (3D). We discuss fundamental aspects of PBC development, including preservation of translational invariance and line connectivity, the choice of initial configurations compatible with PBC and a consistent treatment of image stress. On the practical side, our approach reduces to manageable proportions the computational burden of updating the long-range elastic interactions among dislocation segments. The timing data confirms feasibility and practicality of PBC for large-scale DD simulations in 3D.

Kinetics of Phase Separation in Lithium Bearing HLW Alkaliborosilicate Glasses

1995 ◽  
Vol 412 ◽  
Author(s):  
J. GÖttlicher ◽  
H. J. Pentinghaus
Keyword(s):  
Phase Separation ◽  
Transformation Temperature ◽  
Ostwald Ripening ◽  
Metastable Phase ◽  
Particle Growth ◽  
Glass Frit ◽  
Diffusion Controlled ◽  
Metastable Phase Separation ◽  
Scale Particle ◽  
Kinetics Of

AbstractA TEM study on the kinetics of metastable phase separation in a lithium bearing HLW glass frit is presented. As nothing was known about the kinetics of metastable phase separation below the glass transformation temperature we had to carry out annealing experiments just above and below the transformation temperature, in order to achieve phase separation on a laboratory time scale- Particle growth in the WAKID5 HLW glass frit at 550 °C occurs by a diffusion controlled Ostwald ripening process (about 40 °C above Tg). Metastable phase separation in the lithium bearing glasses even at lower temperatures cannot be excluded from the present study. In NaBSi3O8 glass (Tg ≈ 580 °C) phase separation could be detected at 500 °C well below Tg after about 160 days.

scholarly journals Exploring the jamming transition over a wide range of critical densities

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
Misaki Ozawa ◽  
Ludovic Berthier ◽  
Daniele Coslovich
Keyword(s):  
Large Scale ◽  
Volume Fraction ◽  
Pair Correlation ◽  
Orientational Order ◽  
Finite Size ◽  
Important Change ◽  
Three Dimensions ◽  
Length Scales ◽  
Jamming Transition ◽  
Wide Range

We numerically study the jamming transition of frictionless polydisperse spheres in three dimensions. We use an efficient thermalisation algorithm for the equilibrium hard sphere fluid and generate amorphous jammed packings over a range of critical jamming densities that is about three times broader than in previous studies. This allows us to reexamine a wide range of structural properties characterizing the jamming transition. Both isostaticity and the critical behavior of the pair correlation function hold over the entire range of jamming densities. At intermediate length scales, we find a weak, smooth increase of bond orientational order. By contrast, distorted icosahedral structures grow rapidly with increasing the volume fraction in both fluid and jammed states. Surprisingly, at large scale we observe that denser jammed states show stronger deviations from hyperuniformity, suggesting that the enhanced amorphous ordering inherited from the equilibrium fluid competes with, rather than enhances, hyperuniformity. Finally, finite size fluctuations of the critical jamming density are considerably suppressed in the denser jammed states, indicating an important change in the topography of the potential energy landscape. By considerably stretching the amplitude of the critical “J-line”, our work disentangles physical properties at the contact scale that are associated with jamming criticality, from those occurring at larger length scales, which have a different nature.

3D HPLC-MS with Reversed-Phase Separation Functionality in All Three Dimensions for Large-Scale Bottom-Up Proteomics and Peptide Retention Data Collection

2016 ◽  
Vol 88 (5) ◽  
pp. 2847-2855 ◽  
Author(s):  
Vic Spicer ◽  
Peyman Ezzati ◽  
Haley Neustaeter ◽  
Ronald C. Beavis ◽  
John A. Wilkins ◽  
...  
Keyword(s):  
Phase Separation ◽  
Data Collection ◽  
Large Scale ◽  
Reversed Phase ◽  
Three Dimensions ◽  
Retention Data ◽  
Bottom Up

scholarly journals The Origins of Enhanced and Retarded Crystallization in Nanocomposite Polymers

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1472 ◽  
Author(s):  
Ahmad Jabbarzadeh
Keyword(s):  
Free Space ◽  
Large Scale ◽  
Volume Fraction ◽  
Functional Materials ◽  
Characteristic Size ◽  
Polymeric Systems ◽  
Planar Surfaces ◽  
Extended Length ◽  
Critical Particle Size ◽  
Dynamics Simulations

Controlling the crystallinity of hybrid polymeric systems has an important impact on their properties and is essential for developing novel functional materials. The crystallization of nanocomposite polymers with gold nanoparticles is shown to be determined by free space between nanoparticles. Results of large-scale molecular dynamics simulations reveal while crystallinity is affected by the nanoparticle size and its volume fraction, their combined effects can only be measured by interparticle free space and characteristic size of the crystals. When interparticle free space becomes smaller than the characteristic extended length of the polymer molecule, nanoparticles impede the crystallization because of the confinement effects. Based on the findings from this work, equations for critical particle size or volume fraction that lead to this confinement-induced retardation of crystallization are proposed. The findings based on these equations are demonstrated to agree with the results reported in experiments for nanocomposite systems. The results of simulations also explain the origin of a two-tier crystallization regime observed in some of the hybrid polymeric systems with planar surfaces where the crystallization is initially enhanced and then retarded by the presence of nanoparticles.

Phase Behavior and Shrinking Kinetics of Thermo-Reversible Poly(N-Isopropylacrylamide-2-Hydroxyethyl Methacrylate)

2009 ◽  
Vol 1190 ◽  
Author(s):  
Christine M Leon ◽  
Francisco J Solis ◽  
Brent L Vernon
Keyword(s):  
Phase Separation ◽  
Phase Behavior ◽  
Volume Fraction ◽  
Hydroxyethyl Methacrylate ◽  
Dilute Solution ◽  
Complex Phase ◽  
Second Stage ◽  
Double Exponential ◽  
Liquid Solutions ◽  
Kinetics Of

AbstractWe study the thermodynamic properties of solutions of the physically gelling poly(N-isopropylacrylamide-2-hydroxyethyl methacrylate) [poly(NIPPAm-HEMA)]. We construct its phase diagram and characterize its kinetics of phase separation. This material belongs to a class of thermosensitive, “smart” polymers, that exhibit complex phase behavior. The copolymer studied is liquid at low temperatures and undergoes phase separation near 28°C, with negligible dependence on concentration. Above the transition temperature we observe coexistence between a polymer-dilute solution and a gel. We show that, upon quick heating, liquid solutions form a homogeneous gel that phase separates (shrinks) from a dilute polymer solution. We find that the evolution of the gel volume fraction is well described by a double exponential decay, indicating the presence of two shrinking regimes in a close parallel to the behavior of chemically cross-linked gels. The first stage is characterized by quick water ejection. In the second stage, slower shrinking is observed associated with internal reorganization of the polymers that allows the creation of gel-forming contacts.

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