Computer simulations of nematic drops: Coupling between drop shape and nematic order
Abstract
We perform Monte Carlo computer simulations of nematic drops in equilibrium with their vapor using a Gay-Berne interaction between the rod-like molecules. To generate the drops, we initially perform NPT simulations close to the nematic-vapor coexistence region, allow the system to equilibrate and subsequently induce a sudden volume expansion, followed with NVT simulations. The resultant drops coexist with their vapor and are generally not spherical but elongated, have the rod-like particles tangentially aligned at the surface and an overall nematic orientation along the main axis of the drop. We find that the drop eccentricity increases with increasing molecular elongation, κ. For small κ the nematic texture in the drop is bipolar with two surface defects, or boojums, maximizing their distance along this same axis. For sufficiently high κ, the shape of the drop becomes singular in the vicinity of the defects, and there is a crossover to an almost homogeneous texture; this reflects a transition from a spheroidal to a spindle-like drop.
- Publication:
-
Journal of Chemical Physics
- Pub Date:
- July 2012
- DOI:
- 10.1063/1.4733974
- Bibcode:
- 2012JChPh.137c4505R
- Keywords:
-
- drops;
- elongation;
- liquid crystal phase transformations;
- Monte Carlo methods;
- nematic liquid crystals;
- texture;
- 61.30.Cz;
- 61.30.Gd;
- 61.30.Jf;
- 64.70.mf;
- 61.30.Pq;
- Molecular and microscopic models and theories of liquid crystal structure;
- Orientational order of liquid crystals;
- electric and magnetic field effects on order;
- Defects in liquid crystals;
- Theory and modeling of specific liquid crystal transitions including computer simulation;
- Microconfined liquid crystals: droplets cylinders randomly confined liquid crystals polymer dispersed liquid crystals and porous systems