Capillary ordering and layering transitions in two-dimensional hard-rod fluids

Abstract

In this article we calculate the surface phase diagram of a two-dimensional hard-rod fluid confined between two hard lines. In a first stage we study the semi-infinite system consisting of an isotropic fluid in contact with a single hard line. We have found complete wetting by the columnar phase at the wall-isotropic fluid interface. When the fluid is confined between two hard walls, capillary columnar ordering occurs via a first-order phase transition. For higher chemical potentials the system exhibits layering transitions even for very narrow slits (near the one-dimensional limit). The theoretical model used was a density-functional theory based on the Fundamental-Measure Functional applied to a fluid of hard rectangles in the restricted-orientation approximation (Zwanzig model). The results presented here can be checked experimentally in two-dimensional granular media made of rods, where vertical motions induced by an external source and excluded volume interactions between the grains allow the system to explore those stationary states which entropically maximize packing configurations. We claim that some of the surface phenomena found here can be present in two-dimensional granular-media fluids.

13 pages, 15 figures. To appear in Phys. Rev. E

References in corpus (15)

• Patterns and Collective Behavior in Granular Media: Theoretical Concepts
• Crystallization of a quasi-two-dimensional granular fluid
• Phase behavior of hard spheres confined between parallel hard plates: Manipulation of colloidal crystal structures by confinement
• Tetratic Order in the Phase Behavior of a Hard-Rectangle System
• Spontaneous Patterning of Confined Granular Rods
• Dimensional crossover of the fundamental-measure functional for parallel hard cubes
• Effect of particle geometry on phase transitions in two-dimensional liquid crystals
• Wetting and capillary nematization of binary hard-platelet and hard-rod fluids
• Orientational ordering in hard rectangles: The role of three-body correlations
• A possible experimental test of the thermodynamic approach to granular media
• Equilibrium Distribution of the Inherent States and their Dynamics in Glassy Systems and Granular Media
• Thermodynamics and statistical mechanics of frozen systems in inherent states
• Bulk inhomogeneous phases of anisotropic particles: A fundamental measure functional study of the restricted orientations model
• Orientational transitions in a nematic confined by competing surfaces
• Constrained deformation of a confined solid: a strain induced crystal-smectic transition

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• Competition between capillarity, layering and biaxiality in a confined liquid crystal
• Phase transitions in nanoconfined binary mixtures of highly oriented colloidal rods
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• Confinement effects on the random sequential adsorption packings of elongated particles in a slit
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• Capillary and winding transitions in a confined cholesteric liquid crystal
• Dynamics of Colloidal Cubes and Cuboids in Cylindrical Nanopores