Effect of an external field on the structure and the phase transitions of a confined mixture of neutral and dipolar hard spheres

• Published in: Molecular physics Vol. 113; no. 21; pp. 3216 - 3227
• Main Authors: Chung, S., Malherbe, J.G., Amokrane, S.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 02.11.2015; Taylor & Francis Ltd
• Subjects: colloids; Computational fluid dynamics; Computer simulation; confinement; dipolar interactions; external field; Fluid flow; Fluids; Molecular structure; Monte Carlo methods; Monte Carlo simulation; Phase transformations; Phase transitions; simulation; Spheres; Walls
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268976.2015.1014003

We study by Monte Carlo simulation the model of a binary mixture of neutral and dipolar hard spheres confined between two widely separated planar walls and subjected to a uniform external field. The goal is to investigate the structural response and the phase transitions of a fluid of hard-sphere-like colloids dispersed in a low-permittivity solvent under the combined effect of geometrical confinement and applied field. In a wide slab, the direction of the field, either normal or perpendicular to the walls, remains one of the most important factors that govern the response of the mixture: in normal field, a wide variety of structural effects are evidenced, including partial wetting or drying of the wall; in parallel field, phase separation is favoured with a specific population of the region close to the wall and a clear separation of the two species. These results suggest possible means to modulate the response of the confined fluid for specific needs.