Influence of Volume Fluctuation on End-over-End Rotational Dynamics for a Nematic Liquid-Crystal Phase Molecular-Dynamics Simulation
نویسنده
چکیده
The end-over-end rotational motion of nematic-phase molecules was examined by an isobaric-isothermal molecular-dynamics simulation for a Gay-Berne mesogenic system. The result was compared with the MeierSaupe theory and the previous result obtained from a molecular-dynamics simulation for the same Gay-Berne model at constant volume in order to examine the influence of volume fluctuation on nematic-phase dynamics. The results from the simulation at constant pressure were closer to the theoretical value the retardation factor gk, which is the concept used to interpret reduction of the relaxation time for end-over-end rotational molecular motion, throughout the entire range of the second-rank orientational order parameter hP i and the strength parameter of Maier-Saupe form than were those values for constant volume. Volume fluctuation is important in evaluating the retardation factor gk. This finding significantly increases our understanding of the role of pressure control in the simulation of slow dynamics in the liquid crystalline phase.
منابع مشابه
Numerical simulation of the fluid dynamics in a 3D spherical model of partially liquefied vitreous due to eye movements under planar interface conditions
Partially liquefied vitreous humor is a common physical and biochemical degenerative change in vitreous body which the liquid component gets separated from collagen fiber network and leads to form a region of liquefaction. The main objective of this research is to investigate how the oscillatory motions influence flow dynamics of partial vitreous liquefaction (PVL). So far computational fluid d...
متن کاملMolecular Dynamics Simulation of Potassium Chloride Melting (II. Constant Volume and Constant Pressure Simulation of Filled System)
We have used a simple ionic potential to simulate the melting of KCI pseudo-infinite crystal. Two MD simulations, one with constant Volume and the other with constant pressure condition are performed. These results are compared with the previous micro-sample simulation results. In the constant volume simulation the melting temperature increase substantially with increasing pressure. A method fo...
متن کاملOrientational order and dynamics of the dendritic liquid crystal organo-siloxane tetrapodes determined using dielectric spectroscopy.
The dielectric measurements have been carried out on the two zeroth generation dendrimers with four branched arms (called tetrapodes) based on the siloxane cores. The results are analyzed in the framework of the molecular theory of dielectric permittivity by Maier and Meier for nematogens. At least four molecular processes are resolved in the dielectric relaxation spectra in the nematic phase f...
متن کاملRotational viscosity in a nematic liquid crystal: a theoretical treatment and molecular dynamics simulation.
The rotational viscosity coefficient gamma(1) of 4-n-pentyl-4(')-cyanobiphenyl in the nematic phase is investigated by combination of existing statistical-mechanical approaches (SMAs), based on a rotational diffusion model and computer simulation technique. The SMAs rest on a model in which it is assumed that the reorientation of an individual molecule is a stochastic Brownian motion in a certa...
متن کاملViscosities of the Gay-Berne nematic liquid crystal.
We present molecular dynamics simulation measurements of the viscosities of the Gay-Berne phenomenological model of liquid crystals in the nematic and isotropic phases. The temperature-dependence of the rotational and shear viscosities, including the nonmonotonic behavior of one shear viscosity, are in good agreement with experimental data. The bulk viscosities are significantly larger than the...
متن کامل