A density-functional theory study of the confined soft ellipsoid fluid

Abstract

A system of soft ellipsoid molecules confined between two planar walls is studied using classical density-functional theory. Both the isotropic and nematic phases are considered. The excess free energy is evaluated using two different Ansätze and the intermolecular interaction is incorporated using two different direct correlation functions ͑DCF's͒. The first is a numerical DCF obtained from simulations of bulk soft ellipsoid fluids and the second is taken from the Parsons-Lee theory. In both the isotropic and nematic phases the numerical DCF gives density and order parameter profiles in reasonable agreement with simulation. The Parsons-Lee DCF also gives reasonable agreement in the isotropic phase but poor agreement in the nematic phase.

Structure of a liquid crystalline fluid around a macroparticle: Density functional theory

“…The ρ (s) curves show similar structure as R increases, with a peak at the cylinder surface s = R, a second peak about 5b (one molecular length) from the surface, and some decaying oscillations into the bulk. This is similar to the behaviour seen for a nematic fluid near a wall with homeotropic alignment [20,23]. The size of the peak at contact increases with R at small R. ρ ⊥ (s) also has a peak at contact.…”

“…It excludes the molecules from the cylinder and gives rise to homeotropic (normal) anchoring at the surface. As before [20,21,22,23] the angularly dependent functions are expanded in a set of spherical harmonics, and the assumption of translational invariance along y allows us to write the coefficients as functions of s:…”

“…As before [20,21,22,23] the angularly dependent functions are expanded in a set of spherical harmonics, and the assumption of translational invariance along y allows us to write the coefficients as functions of s:…”

Monte Carlo simulations of liquid crystals between microstructured substrates

“…Due to the importance of interactions between LCs and solid substrates there have been a large number of studies performed with molecular simulations [5][6][7][8][9][10], and theories such as density functional theory (DFT) [8,[11][12][13]. These have largely concentrated an simple homogeneous surfaces and has investigated phenomena such as surface anchoring strength [8,9] and capillary nematization [14,15].Recently there have been a number of studies that have investigated the effect of changes in the surface structure on LC.…”

Monte Carlo simulations of liquid crystals near rough walls

“…In the first the wall is modelled by a perfect crystalline array 2 . The second, more coarse grained model, uses an external potential function that depends only on the distance from the wall 3,4 . While attractive from a theoretical standpoint, it has long been recognised that deviations from these ideal surfaces can affect the properties of the surface 5 .…”