Abstract
The complex interplay of molecular scale effects, nonlinearities in the orientational field and long-range elastic forces makes liquid-crystal physics very challenging. A consistent way to extract information from the microscopic, molecular scale up to the meso- and macroscopic scale is still missing. Here, we develop a hybrid procedure that bridges this gap by combining extensive Monte Carlo (MC) simulations, a local Landau-de Gennes theory, classical density functional theory, and finite-size scaling theory. As a test case to demonstrate the power and validity of our novel approach we study the effective interaction among colloids with Boojum defect topology immersed in a nematic liquid crystal. In particular, at sufficiently small separations colloids attract each other if the angle between their center-of-mass distance vector and the far-field nematic director is about 30°. Using the effective potential in coarse-grained two-dimensional MC simulations we show that self-assembled structures formed by the colloids are in excellent agreement with experimental data.
Highlights
Liquid crystals are fluids made of molecules that lack spherical symmetry
At y E 301 the colloids attract each other whereas at y = 01 and 901 repulsion between the colloids is observed. To study these effects starting from a molecular-level based description we employ a combination of Monte Carlo (MC) simulations in the isothermal–isobaric and canonical ensembles, two-dimensional (2D), coarse-grained MC simulations in the canonical ensemble, classical density functional theory (DFT), concepts of finite-size scaling (FSS), and Landau–de Gennes (LdG) theory to investigate the effective interaction between a pair of spherical, chemically homogeneous colloids mediated by a nematic host phase
Our hybrid approach combines molecular-scale methods and theories such as MC computer simulations, classical DFT, and elements of FSS theory with macroscopic theories such as LdG and the Frank–Oseen treatment of the free-energy density associated with elastic deformations of the director field
Summary
Liquid crystals are fluids made of molecules that lack spherical symmetry. Instead, their molecules contain elongated, rigid cores that form nematic liquid crystals, or disk-like cores that produce discotic liquid crystals or even more complex shapes. At y E 301 the colloids attract each other whereas at y = 01 and 901 repulsion between the colloids is observed To study these effects starting from a molecular-level based description we employ a combination of Monte Carlo (MC) simulations in the isothermal–isobaric and canonical ensembles, two-dimensional (2D), coarse-grained MC simulations in the canonical ensemble, classical density functional theory (DFT), concepts of finite-size scaling (FSS), and Landau–de Gennes (LdG) theory to investigate the effective interaction between a pair of spherical, chemically homogeneous colloids mediated by a nematic host phase. The remainder of this manuscript is organized as follows. The following three sections are devoted to introducing the various constituents of our model and to specifying their interactions with one another
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
