Kinetics of the Ordered Phase Growth in Alkylene‐Aromatic Dimers Across the Phase Transition From Isotropic to Nematic State

Kinetics of the nematic droplet growth during the phase transition from the isotropic to ordered state under cooling at a rate of 1°C/min was studied for two alkylene‐aromatic dimers with different dipole architectures. The linear size (diameter) of droplets revealed in the optical images was treated statistically and the resulting statistical size distributions were described in the framework of irreversible thermodynamics. For the dimer with orthogonal orientation of the dipole moment, two stationary regimes of the nematic phase growth were recognized: nucleus growth and nucleus coarsening. Both regimes were subsequently described using the universal growth law. For the dimer with parallel orientation of the dipole moment, the droplet size remains roughly constant, although the number of nematic germs increases with time.

Keywords:

• Liquid crystalline dimers
• Nematic phase growth
• Phase transition
• Scaling function
• Statistical size distribution

Acknowledgment

This work was financially supported by the Russian Foundation for Basic Research (grant 06‐08‐00195).