### Abstract

The effect of strong confinement on the positional and orientational ordering is examined in a system of hard rectangular rods with length L and diameter D (L>D) using the Parsons-Lee modification of the second virial density-functional theory. The rods are nonmesogenic (L/D<3) and confined between two parallel hard walls, where the width of the pore (H) is chosen in such a way that both planar (particle's long axis parallel to the walls) and homeotropic (particle's long axis perpendicular to the walls) orderings are possible and a maximum of two layers is allowed to form in the pore. In the extreme confinement limit of H≤2D, where only one-layer structures appear, we observe a structural transition from a planar to a homeotropic fluid layer with increasing density, which becomes sharper as L→H. In wider pores (2D<H<3D) planar order with two layers, homeotropic order, and even combined bilayer structures (one layer is homeotropic, while the other is planar) can be stabilized at high densities. Moreover, first-order phase transitions can be seen between different structures. One of them emerges between a monolayer and a bilayer with planar orders at relatively low packing fractions.

Original language | English |
---|---|

Article number | 012703 |

Journal | Physical Review E |

Volume | 97 |

Issue number | 1 |

DOIs | |

Publication status | Published - Jan 16 2018 |

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### ASJC Scopus subject areas

- Statistics and Probability
- Condensed Matter Physics
- Statistical and Nonlinear Physics

### Cite this

*Physical Review E*,

*97*(1), [012703]. https://doi.org/10.1103/PhysRevE.97.012703

**Ordering transitions of weakly anisotropic hard rods in narrow slitlike pores.** / Aliabadi, Roohollah; Gurin, Péter; Velasco, Enrique; Varga, S.

Research output: Contribution to journal › Article

*Physical Review E*, vol. 97, no. 1, 012703. https://doi.org/10.1103/PhysRevE.97.012703

}

TY - JOUR

T1 - Ordering transitions of weakly anisotropic hard rods in narrow slitlike pores

AU - Aliabadi, Roohollah

AU - Gurin, Péter

AU - Velasco, Enrique

AU - Varga, S.

PY - 2018/1/16

Y1 - 2018/1/16

N2 - The effect of strong confinement on the positional and orientational ordering is examined in a system of hard rectangular rods with length L and diameter D (L>D) using the Parsons-Lee modification of the second virial density-functional theory. The rods are nonmesogenic (L/D<3) and confined between two parallel hard walls, where the width of the pore (H) is chosen in such a way that both planar (particle's long axis parallel to the walls) and homeotropic (particle's long axis perpendicular to the walls) orderings are possible and a maximum of two layers is allowed to form in the pore. In the extreme confinement limit of H≤2D, where only one-layer structures appear, we observe a structural transition from a planar to a homeotropic fluid layer with increasing density, which becomes sharper as L→H. In wider pores (2D<H<3D) planar order with two layers, homeotropic order, and even combined bilayer structures (one layer is homeotropic, while the other is planar) can be stabilized at high densities. Moreover, first-order phase transitions can be seen between different structures. One of them emerges between a monolayer and a bilayer with planar orders at relatively low packing fractions.

AB - The effect of strong confinement on the positional and orientational ordering is examined in a system of hard rectangular rods with length L and diameter D (L>D) using the Parsons-Lee modification of the second virial density-functional theory. The rods are nonmesogenic (L/D<3) and confined between two parallel hard walls, where the width of the pore (H) is chosen in such a way that both planar (particle's long axis parallel to the walls) and homeotropic (particle's long axis perpendicular to the walls) orderings are possible and a maximum of two layers is allowed to form in the pore. In the extreme confinement limit of H≤2D, where only one-layer structures appear, we observe a structural transition from a planar to a homeotropic fluid layer with increasing density, which becomes sharper as L→H. In wider pores (2D<H<3D) planar order with two layers, homeotropic order, and even combined bilayer structures (one layer is homeotropic, while the other is planar) can be stabilized at high densities. Moreover, first-order phase transitions can be seen between different structures. One of them emerges between a monolayer and a bilayer with planar orders at relatively low packing fractions.

UR - http://www.scopus.com/inward/record.url?scp=85040747472&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85040747472&partnerID=8YFLogxK

U2 - 10.1103/PhysRevE.97.012703

DO - 10.1103/PhysRevE.97.012703

M3 - Article

AN - SCOPUS:85040747472

VL - 97

JO - Physical review. E

JF - Physical review. E

SN - 2470-0045

IS - 1

M1 - 012703

ER -