Self-assembly in mixtures with competing interactions
| Autor: | Oksana Patsahan, Alina Ciach, Marek Litniewski |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Mesoscopic physics
Materials science Statistical Mechanics (cond-mat.stat-mech) FOS: Physical sciences 02 engineering and technology General Chemistry Crystal structure Condensed Matter - Soft Condensed Matter 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Charged particle Molecular dynamics Liquid crystal Chemical physics Phase (matter) 0103 physical sciences Soft Condensed Matter (cond-mat.soft) Self-assembly 010306 general physics 0210 nano-technology Condensed Matter - Statistical Mechanics Phase diagram |
| Zdroj: | Soft Matter |
| ISSN: | 1744-6848 |
| Popis: | A binary mixture of particles interacting with spherically-symmetric potentials leading to microsegregation is studied by theory and molecular dynamics (MD) simulations. We consider spherical particles with equal diameters and volume fractions. Motivated by the mixture of oppositely charged particles with different adsorption preferences immersed in near-critical binary solvent, we assume short-range attraction long-range repulsion for the interaction between like particles, and short range repulsion long-range attraction for the interaction between different ones. In order to predict structural and thermodynamic properties of such complex mixtures, we develop a theory combining the density functional and field-theoretic methods. We show that concentration fluctuations in mesoscopic regions lead to a qualitative change of the phase diagram compared to mean-field predictions. Both theory and MD simulations show coexistence of a low-density disordered phase with a high-density phase with alternating layers rich in the first and the second component. The density and the degree of order of the ordered phase decrease with increasing temperature, up to a temperature where the theory predicts a narrow two-phase region with increasing density of both phases for increasing temperature. MD simulations show that monocrystals of the solid and liquid crystals have a prolate shape with the axis parallel to the direction of concentration oscillations, and the deviation from the spherical shape increases with increasing periodic order. 32 pages, 14 figures |
| Databáze: | OpenAIRE |
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