Molecular simulation of liquid crystals: progress towards a better understanding of bulk structure and the prediction of material properties

Abstract

This tutorial review covers recent progress in the field of computer simulation of liquid crystals. The development of the main ''molecular-based'' models for liquid crystals is described. These include lattice models, coarse-grained single site models based on hard and soft interaction potentials, atomistic models and multi-site coarse-grained models. A brief historical review is followed by an assessment of some of the new areas in this field, with an emphasis on understanding of molecular structure in liquid crystal phases and the prediction of bulk material properties. The article also looks to link the field of liquid crystal simulation with important developments in areas such as polymer simulation, lyotropic liquid crystals and model membranes.

The phase behavior of linear and partially flexible hard-sphere chain fluids and the solubility of hard spheres in hard-sphere chain fluids

“…This was first predicted theoretically by Onsager 8 and observed later in molecular simulation studies of hard disks, 9, 10 hard ellipsoids, [11][12][13][14] hard spherocylinders, [15][16][17][18][19][20] and cut hard spheres. 21 Frenkel, 22 Allen, 23 Care and Cleaver, 24 and Wilson 25 provided excellent reviews on the molecular simulation of liquid crystals.…”

Energetic and Entropic Contributions to the Landau–de Gennes Potential for Gay–Berne Models of Liquid Crystals

“…As a macroscopic quantity, the Landau-de Gennes free energy is usually introduced phenomenologically as a low-order polynomial of the order parameter, in close analogy to the Ginzburg-Landau theory of phase transitions. Despite considerable advances in molecular simulations [9] and theoretical efforts [10,11], the long-standing question of how to derive the Landau-de Gennes free energy from a microscopic model has not been fully resolved yet. Since many length-and time-scales are present in typical liquid-crystalline systems, there is an urgent need for systematic coarse-graining approaches [12].…”

Liquid-crystal phase equilibria of Lennard-Jones chains

“…Simulations based on coarse-grained models can access longer time and length scales than their atomistic counterparts, allowing a bulk description of fluids. Coarse-grained models are commonly used to represent a simplified picture of large molecules, such as biomolecules [12][13][14][15][16], polymers [17][18][19][20][21][22], or liquid crystals [23][24][25][26][27][28]. Moreover, simulation results obtained from coarse-grained models can be directly compared with theoretical predictions that are based on a well-defined Hamiltonian, such as the family of perturbation theories developed from the statistical association fluid theory (SAFT) [29][30][31][32][33][34][35][36].…”