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Ma W, Zhou Z, Ismail N, Tocci E, Figoli A, Khayet M, Matsuura T, Cui Z, Tavajohi N. Membrane formation by thermally induced phase separation: Materials, involved parameters, modeling, current efforts and future directions. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.121303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Sigalotti LDG, Troconis J, Sira E, Peña-Polo F, Klapp J. Diffuse-interface modeling of liquid-vapor coexistence in equilibrium drops using smoothed particle hydrodynamics. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:013021. [PMID: 25122383 DOI: 10.1103/physreve.90.013021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Indexed: 06/03/2023]
Abstract
We study numerically liquid-vapor phase separation in two-dimensional, nonisothermal, van der Waals (vdW) liquid drops using the method of smoothed particle hydrodynamics (SPH). In contrast to previous SPH simulations of drop formation, our approach is fully adaptive and follows the diffuse-interface model for a single-component fluid, where a reversible, capillary (Korteweg) force is added to the equations of motion to model the rapid but smooth transition of physical quantities through the interface separating the bulk phases. Surface tension arises naturally from the cohesive part of the vdW equation of state and the capillary forces. The drop models all start from a square-shaped liquid and spinodal decomposition is investigated for a range of initial densities and temperatures. The simulations predict the formation of stable, subcritical liquid drops with a vapor atmosphere, with the densities and temperatures of coexisting liquid and vapor in the vdW phase diagram closely matching the binodal curve. We find that the values of surface tension, as determined from the Young-Laplace equation, are in good agreement with the results of independent numerical simulations and experimental data. The models also predict the increase of the vapor pressure with temperature and the fitting to the numerical data reproduces very well the Clausius-Clapeyron relation, thus allowing for the calculation of the vaporization pressure for this vdW fluid.
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Affiliation(s)
- Leonardo Di G Sigalotti
- Centro de Física, Instituto Venezolano de Investigaciones Científicas, IVIC, Apartado Postal 20632, Caracas 1020-A, Venezuela
| | - Jorge Troconis
- Centro de Física, Instituto Venezolano de Investigaciones Científicas, IVIC, Apartado Postal 20632, Caracas 1020-A, Venezuela
| | - Eloy Sira
- Centro de Física, Instituto Venezolano de Investigaciones Científicas, IVIC, Apartado Postal 20632, Caracas 1020-A, Venezuela
| | - Franklin Peña-Polo
- Centro de Física, Instituto Venezolano de Investigaciones Científicas, IVIC, Apartado Postal 20632, Caracas 1020-A, Venezuela
| | - Jaime Klapp
- Departamento de Física, Instituto Nacional de Investigaciones Nucleares, ININ, Km. 36.5, Carretera México-Toluca, 52750, La Marquesa, Estado de México, Mexico and Departamento de Matemáticas, Cinvestav del Instituto Politécnico Nacional (I.P.N.), 07360, México City, Mexico
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Light scattering behavior and the kinetics of pressure-induced phase separation in solutions of poly(ε-caprolactone) in acetone + CO2 binary fluid mixtures. POLYMER 2013. [DOI: 10.1016/j.polymer.2013.07.068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Winkler A, Virnau P, Binder K, Winkler RG, Gompper G. Hydrodynamic mechanisms of spinodal decomposition in confined colloid-polymer mixtures: a multiparticle collision dynamics study. J Chem Phys 2013; 138:054901. [PMID: 23406143 DOI: 10.1063/1.4789267] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A multiscale model for a colloid-polymer mixture is developed. The colloids are described as point particles interacting with each other and with the polymers with strongly repulsive potentials, while polymers interact with each other with a softer potential. The fluid in the suspension is taken into account by the multiparticle collision dynamics method (MPC). Considering a slit geometry where the suspension is confined between parallel repulsive walls, different possibilities for the hydrodynamic boundary conditions (b.c.) at the walls (slip versus stick) are treated. Quenching experiments are considered, where the system volume is suddenly reduced (keeping the density of the solvent fluid constant, while the colloid and polymer particle numbers are kept constant) and thus an initially homogeneous system is quenched deeply into the miscibility gap, where it is unstable. For various relative concentrations of colloids and polymers, the time evolution of the growing colloid-rich and polymer-rich domains are studied by molecular dynamics simulation, taking hydrodynamic effects mediated by the solvent into account via MPC. It is found that the domain size [script-l](d)(t) grows with time t as [script-l](d)(t) [proportionality] t(1/3) for stick and (at late stages) as [script-l](d)(t) [proportionality] t(2/3) for slip b.c., while break-up of percolating structures can cause a transient "arrest" of growth. While these findings apply for films that are 5-10 colloid diameters wide, for ultrathin films (1.5 colloid diameters wide) a regime with [script-l](d)(t) [proportionality] t(1/2) is also identified for rather shallow quenches.
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Affiliation(s)
- Alexander Winkler
- Insitut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55099 Mainz, Germany
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Ahmad S, Corberi F, Das SK, Lippiello E, Puri S, Zannetti M. Aging and crossovers in phase-separating fluid mixtures. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:061129. [PMID: 23367915 DOI: 10.1103/physreve.86.061129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 11/22/2012] [Indexed: 06/01/2023]
Abstract
We use state-of-the-art molecular dynamics simulations to study hydrodynamic effects on aging during kinetics of phase separation in a fluid mixture. The domain growth law shows a crossover from a diffusive regime to a viscous hydrodynamic regime. There is a corresponding crossover in the autocorrelation function from a power-law behavior to an exponential decay. While the former is consistent with theories for diffusive domain growth, the latter results as a consequence of faster advective transport in fluids for which an analytical justification has been provided.
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Affiliation(s)
- Shaista Ahmad
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore 560064, India
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