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.
Department of Physics, University of Ioannina, 451 10 Ioannina, Greece.
Mahdy M
MM
Elmahdy
Mihail
M
Mondeshki
Xi
X
Dou
Hans-Jürgen
HJ
Butt
Hans W
HW
Spiess
Klaus
K
Müllen
George
G
Floudas