Computer Simulation of Shear-Induced Phase Separation and Rheology in Two-Component Viscoelastic Fluid

1997 ◽  
Vol 11 (09n10) ◽  
pp. 379-389 ◽  
Author(s):  
Tohru Okuzono
Keyword(s):  
Phase Separation ◽  
Shear Rate ◽  
Past History ◽  
Coexistence Curve ◽  
Two Dimensions ◽  
Equilibrium Coexistence ◽  
Stress Coefficient ◽  
Two Component ◽  
Viscoelastic Effects ◽  
Remarkable Result

We numerically study the dynamics of polymer solutions in two dimensions at a temperature above the equilibrium coexistence curve under shear flow. Our model is based on the Lagrangian picture of fluid dynamics. We can incorporate viscoelastic effects into the model by introducing a kind of fluid particles which have memories of their own past history. We carry out computer simulations and observe that shear-induced phase separation occur and the system shows a shear thinning rheological property. The most remarkable result is that the dependence of normal stress coefficient on shear rate changes at a shear rate which is comparable to inverse of the stress relaxation time. Our results imply that the shear-induced phase separation can change qualitative features of rheological response.

scholarly journals Two-component electronic phase separation in the doped Mott insulator Y1−xCaxTiO3

2021 ◽  
Vol 104 (4) ◽  
Author(s):  
S. Hameed ◽  
J. Joe ◽  
D. M. Gautreau ◽  
J. W. Freeland ◽  
T. Birol ◽  
...  
Keyword(s):  
Phase Separation ◽  
Mott Insulator ◽  
Electronic Phase Separation ◽  
Electronic Phase ◽  
Two Component ◽  
Doped Mott Insulator

scholarly journals A computational study of phase separation in polymer solutions under a double quench

2021 ◽  
Author(s):  
Ehsan Hosseini
Keyword(s):  
Phase Separation ◽  
Polymer Solution ◽  
Spinodal Decomposition ◽  
Computational Study ◽  
Stable State ◽  
Thermal Quenching ◽  
Nucleation And Growth ◽  
Two Dimensions ◽  
Numerical Work ◽  
Binary Polymer

Polymer-dispersed liquid crystals (PDLCs) are a relatively new class of materials used for many applications ranging from switchable windows to projection displays. PDLSs are formed by spinodal decomposition induced by thermal quenching or polymerization. The objective of the present study is to introduce a new mechanism of phase separation in a binary polymer solution and develop a mathematical model and computer simulation to describe the phase separation during the early and intermediate stages of nucleation and growth and spinodal decomposition induced by thermal double quenching. The growth equilibrium limits of phase separation as well as phase transition are calculated by taking into consideration the Flory-Huggins theory for the free energy of mixing. A two step quench is modeled using Cahn-Hilliard theory for asymmetric binary polymer solution which is quenched from a stable state in the one-phase region to a metastable region where nucleation and growth occurs. The solution is allowed to coarsen for different time periods before a second quench was applied to a point further inside the phase diagram. The numerical results in two dimensions replicate the experimental and numerical work that has been recently done and published.

scholarly journals A computational study of phase separation in polymer solutions under a double quench

2021 ◽  
Author(s):  
Ehsan Hosseini
Keyword(s):  
Phase Separation ◽  
Polymer Solution ◽  
Spinodal Decomposition ◽  
Computational Study ◽  
Stable State ◽  
Thermal Quenching ◽  
Nucleation And Growth ◽  
Two Dimensions ◽  
Numerical Work ◽  
Binary Polymer

Polymer-dispersed liquid crystals (PDLCs) are a relatively new class of materials used for many applications ranging from switchable windows to projection displays. PDLSs are formed by spinodal decomposition induced by thermal quenching or polymerization. The objective of the present study is to introduce a new mechanism of phase separation in a binary polymer solution and develop a mathematical model and computer simulation to describe the phase separation during the early and intermediate stages of nucleation and growth and spinodal decomposition induced by thermal double quenching. The growth equilibrium limits of phase separation as well as phase transition are calculated by taking into consideration the Flory-Huggins theory for the free energy of mixing. A two step quench is modeled using Cahn-Hilliard theory for asymmetric binary polymer solution which is quenched from a stable state in the one-phase region to a metastable region where nucleation and growth occurs. The solution is allowed to coarsen for different time periods before a second quench was applied to a point further inside the phase diagram. The numerical results in two dimensions replicate the experimental and numerical work that has been recently done and published.

Photoinduced Phase Separation of Gold in Two-Component Nanoparticles

Small ◽  
2006 ◽  
Vol 2 (11) ◽  
pp. 1335-1339 ◽  
Author(s):  
Gabriella S. Métraux ◽  
Rongchao Jin ◽  
Chad A. Mirkin
Keyword(s):  
Phase Separation ◽  
Two Component

Viscoelastic Effects on the Phase Separation in Thermoplastics-Modified Epoxy Resin

2003 ◽  
Vol 36 (20) ◽  
pp. 7746-7751 ◽  
Author(s):  
Wenjun Gan ◽  
Yingfeng Yu ◽  
Minghai Wang ◽  
Qingsheng Tao ◽  
Shanjun Li
Keyword(s):  
Phase Separation ◽  
Epoxy Resin ◽  
Viscoelastic Effects ◽  
Modified Epoxy

scholarly journals Denaturation Behavior and Kinetics of Single- and Multi-Component Protein Systems at Extrusion-Like Conditions

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2145
Author(s):  
Maria Quevedo ◽  
Heike P. Karbstein ◽  
M. Azad Emin
Keyword(s):  
Phase Separation ◽  
Shear Rate ◽  
Whey Protein ◽  
Reaction Order ◽  
Local Level ◽  
Reaction Rates ◽  
Model Systems ◽  
Protein Model ◽  
Kinetics Of ◽  
Component Protein

In this study, the influence of defined extrusion-like treatment conditions on the denaturation behavior and kinetics of single- and multi-component protein model systems at a protein concentration of 70% (w/w) was investigated. α-Lactalbumin (αLA) and β-Lactoglobulin (βLG), and whey protein isolate (WPI) were selected as single- and multi-component protein model systems, respectively. To apply defined extrusion-like conditions, treatment temperatures in the range of 60 and 100 °C, shear rates from 0.06 to 50 s⁻1, and treatment times up to 90 s were chosen. While an aggregation onset temperature was determined at approximately 73 °C for WPI systems at a shear rate of 0.06 s⁻1, two significantly different onset temperatures were determined when the shear rate was increased to 25 and 50 s⁻1. These two different onset temperatures could be related to the main fractions present in whey protein (βLG and αLA), suggesting shear-induced phase separation. Application of additional mechanical treatment resulted in an increase in reaction rates for all the investigated systems. Denaturation was found to follow 2.262 and 1.865 order kinetics for αLA and WPI, respectively. The reaction order of WPI might have resulted from a combination of a lower reaction order in the unsheared system (i.e., fractional first order) and higher reaction order for sheared systems, probably due to phase separation, leading to isolated behavior of each fraction at the local level (i.e., fractional second order).

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