Slow kinetics of phase transformation in a dipole-functionalized discotic liquid crystal.
The kinetics of phase transformation from the liquid crystalline mesophase to the crystalline phase has been studied in a model dipole-functionalized hexabenzocoronene derivative by x-ray diffraction, solid state NMR recoupling techniques, and dielectric spectroscopy. These probes revealed long-lived metastability and an intermediate state involving a change in the unit cell prior to crystallization. The barrier properties were dominant and amount to 1 and 2.5 eV, respectively, for the unit cell transformation and crystallization processes. These effects should be considered in the design of discotic liquid crystals for electronic applications.
Elmahdy
Mahdy M
MM
Department of Physics, University of Ioannina, 451 10 Ioannina, Greece.
Mondeshki
Mihail
M
Dou
Xi
X
Butt
Hans-Jürgen
HJ
Spiess
Hans W
HW
Müllen
Klaus
K
Floudas
George
G