Description of Phase Behavior of Polymer Blends by Different Equation-of-State Theories. 1. Phase Diagrams and Thermodynamic Reasons for Mixing and Demixing

1995 ◽  
Vol 28 (19) ◽  
pp. 6586-6594 ◽  
Author(s):  
Bernd Rudolf ◽  
Hans-Joachim Cantow
Keyword(s):  
Equation Of State ◽  
Polymer Blends ◽  
Phase Behavior ◽  
Phase Diagrams

A simulation study of self-assembly of ABC star terpolymers confined between two parallel surfaces

Soft Matter ◽  
2021 ◽  
Author(s):  
Zhiyao Liu ◽  
Zheng Wang ◽  
Yuhua Yin ◽  
Run Jiang ◽  
Baohui Li
Keyword(s):  
Simulated Annealing ◽  
Phase Behavior ◽  
Phase Diagrams ◽  
Simulation Study ◽  
Self Assembly ◽  
Simulated Annealing Method ◽  
Parallel Surfaces ◽  
Annealing Method

Phase behavior of ABC star terpolymers confined between two identical parallel surfaces is systematically studied with a simulated annealing method. Several phase diagrams are constructed for systems with different bulk...

scholarly journals Revisiting Kelvin equation and Peng–Robinson equation of state for accurate modeling of hydrocarbon phase behavior in nano capillaries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ilyas Al-Kindi ◽  
Tayfun Babadagli
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Equation Of State ◽  
Phase Behavior ◽  
Pore Radius ◽  
Microfluidic Chips ◽  
Tight Sandstone ◽  
Kelvin Equation ◽  
Rock Samples ◽  
Robinson Equation

AbstractThe thermodynamics of fluids in confined (capillary) media is different from the bulk conditions due to the effects of the surface tension, wettability, and pore radius as described by the classical Kelvin equation. This study provides experimental data showing the deviation of propane vapour pressures in capillary media from the bulk conditions. Comparisons were also made with the vapour pressures calculated by the Peng–Robinson equation-of-state (PR-EOS). While the propane vapour pressures measured using synthetic capillary medium models (Hele–Shaw cells and microfluidic chips) were comparable with those measured at bulk conditions, the measured vapour pressures in the rock samples (sandstone, limestone, tight sandstone, and shale) were 15% (on average) less than those modelled by PR-EOS.

scholarly journals Pore-Scale Simulation of Confined Phase Behavior with Pore Size Distribution and Its Effects on Shale Oil Production

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1315
Author(s):  
Jingwei Huang ◽  
Hongsheng Wang
Keyword(s):  
Phase Equilibrium ◽  
Equation Of State ◽  
Pore Size Distribution ◽  
Phase Behavior ◽  
Pore Size ◽  
Size Distribution ◽  
Critical Role ◽  
Shale Oil ◽  
Pore Scale ◽  
Modified Equation

Confined phase behavior plays a critical role in predicting production from shale reservoirs. In this work, a pseudo-potential lattice Boltzmann method is applied to directly model the phase equilibrium of fluids in nanopores. First, vapor-liquid equilibrium is simulated by capturing the sudden jump on simulated adsorption isotherms in a capillary tube. In addition, effect of pore size distribution on phase equilibrium is evaluated by using a bundle of capillary tubes of various sizes. Simulated coexistence curves indicate that an effective pore size can be used to account for the effects of pore size distribution on confined phase behavior. With simulated coexistence curves from pore-scale simulation, a modified equation of state is built and applied to model the thermodynamic phase diagram of shale oil. Shifted critical properties and suppressed bubble points are observed when effects of confinement is considered. The compositional simulation shows that both predicted oil and gas production will be higher if the modified equation of state is implemented. Results are compared with those using methods of capillary pressure and critical shift.

Phase behavior of semicrystalline polymer blends

Polymer ◽  
2004 ◽  
Vol 45 (11) ◽  
pp. 3671-3679 ◽  
Author(s):  
Chieh-Tsung Lo ◽  
Soenke Seifert ◽  
Pappannan Thiyagarajan ◽  
Balaji Narasimhan
Keyword(s):  
Polymer Blends ◽  
Phase Behavior ◽  
Semicrystalline Polymer

Phase Relationship Studies of Silicon Nitride System—A Key to Materials Design

1992 ◽  
Vol 287 ◽  
Author(s):  
T.S. Yen ◽  
W.Y. Sun
Keyword(s):  
Elevated Temperature ◽  
Silicon Nitride ◽  
Grain Boundary ◽  
Phase Behavior ◽  
Phase Diagrams ◽  
Room Temperature ◽  
Phase Relationship ◽  
Materials Design ◽  
Basic Approach ◽  
System A

ABSTRACTAdditions and revisions to several of the most important phase diagrams and phase behavior diagrams in the silicon nitride field are reviewed in this work, with emphasis on the Y-Si-A1-O-N system. This information is further used to make observations on the promising silicon nitride systems containing either highly refractory grain boundary phases or compatible matrix phases of desirable properties. Examples are provided to illustrate the advantage of such a basic approach to materials design. Hardness, toughness, strength at room temperature and elevated temperature and even sinterability can all be improved by adopting such an approach.

scholarly journals Curvature-Based Equation of State for Microemulsion-Phase Behavior

SPE Journal ◽  
2018 ◽  
Vol 24 (02) ◽  
pp. 647-659 ◽  
Author(s):  
V. A. Torrealba ◽  
R. T. Johns ◽  
H.. Hoteit
Keyword(s):  
Equation Of State ◽  
Phase Behavior ◽  
Oil Recovery ◽  
Industrial Applications ◽  
Data Availability ◽  
Behavior Modeling ◽  
Average Curvature ◽  
Wide Range ◽  
Definition Of ◽  
Spheroidal Geometry

Summary An accurate description of the microemulsion-phase behavior is critical for many industrial applications, including surfactant flooding in enhanced oil recovery (EOR). Recent phase-behavior models have assumed constant-shaped micelles, typically spherical, using net-average curvature (NAC), which is not consistent with scattering and microscopy experiments that suggest changes in shapes of the continuous and discontinuous domains. On the basis of the strong evidence of varying micellar shape, principal micellar curves were used recently to model interfacial tensions (IFTs). Huh's scaling equation (Huh 1979) also was coupled to this IFT model to generate phase-behavior estimates, but without accounting for the micellar shape. In this paper, we present a novel microemulsion-phase-behavior equation of state (EoS) that accounts for changing micellar curvatures under the assumption of a general-prolate spheroidal geometry, instead of through Huh's equation. This new EoS improves phase-behavior-modeling capabilities and eliminates the use of NAC in favor of a more-physical definition of characteristic length. Our new EoS can be used to fit and predict microemulsion-phase behavior irrespective of IFT-data availability. For the cases considered, the new EoS agrees well with experimental data for scans in both salinity and composition. The model also predicts phase-behavior data for a wide range of temperature and pressure, and it is validated against dynamic scattering experiments to show the physical significance of the approach.

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