Kinetic structures in multi-phase liquid-crystalline composite materials

Abstract

A mesoscopic kinetic model for phase separation in the presence of liquid crystalline order has been formulated and solved using high performance numerical methods. The thermodynamic phase diagram on temperature–polymer concentration plane indicates the presence of coexistence regions between isotropic and liquid crystalline phases. These regions are partitioned by the phase-separation spinodal and the phase-ordering spinodal. We characterize the morphologies following temperature quenches in the phase diagram. The scenario is completely different from isotropic mixing since the continuous phase exhibits liquid crystalline ordering. Microdomains of the dispersed phase induce long- and short-range forces affecting the kinetics of the phase separation and the emerging structures. Presence of topological defects and elastic distortions around the microdomains formed during the phase separation dominate the morphology. The free energy of the system establishes dynamics and correlations of the morphological structures.

Keywords:

• Multiphase
• Phase separation
• Microdomain structures
• Topological defects
• Phase diagram

Acknowledgements

This work was supported in part by the Air Force Office of Scientific Research, Mathematical and Space Science Program, under grant number F49620-00-1-0341. This work was also supported in part by the ERC Program of the National Science Foundation under Award Number EEC-9731680.