Cell size dependence of orientational order of uniaxial liquid crystals in flat slit

In order to investigate the ordered structure of nematic liquid crystal molecules confined in a nanoslit, we carried out a classical molecular dynamics simulation of uniaxial prolate Gay–Berne particles in a flat, structureless slit at several temperatures. When the slit gap is so small that the system is not assumed as the bulk, particles in the slit possess orientationally ordered structures different from ones in the bulk. The weak spacial orientational correlation existed when the temperature corresponded to the isotropic phase in the bulk system. The first order isotropic–nematic phase transition was not clearly observed and the transitional phenomenon of the creation and annihilation of the uniaxial domains were observed. These results revealed that the ordered structure depends on the number of particles, in other words, cell size, and that the system with 100,000 or more particles gives reasonable results of an infinitely wide slit. The number of particles is converted into up to 220 particles of the length of the base.