Coarse-Grained Molecular Dynamic Simulations for Lyotropic Liquid-Crystalline Solutions of Semiflexible Rod-Like Molecules

Abstract

Coarse-grained molecular dynamic simulations are performed for lyotropic liquid-crystalline (LC) solutions of semiflexible rod-like molecules, which are realized by harmonic-stretching potential and angle-bending potential. The phase behavior and molecular dynamic information are investigated. When the concentration of rod-like molecules increases, the solution transits from isotropic to binary phase and then to anisotropic phase. The influences of chain length, temperature, solvent solubility, and chain rigidity are studied. The simulation for the phase behavior successfully reproduces the predictions of Flory lattice theory on the rod-like molecule solution. The decrement of the chain rigidity increases the concentration of phase transition, and the apparent persistence length is increases by molecular alignments with LC formations at higher concentrations.

Keywords:

• lyotropic liquid crystal
• molecular dynamic simulation
• persistence length
• phase behavior
• rod-like molecule

ACKNOWLEDGMENT

This work was supported by a Grant-in-Aid for “Academic Frontier” Project for Private Universities; matching fund subsidy from Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, 2001–2005 and 2006–2008; and National Natural Science Foundation of China (20574018, 50673026). Support from Program for New Century Excellent Talents in University in China (NCET-04–0410) is also appreciated.

Notes

R is the gas constant and A _v is the Avogadro's number