Biomedical Engineering Reference
In-Depth Information
N
N
(H
2
C)
14
O
O
O
N
O(CH
2
)
14
N
N
NH
O
(H
2
C)
14
O
(H
2
C)
14
O
O
N
N
N
O(CH
2
)
14
O
N
O
O(CH
2
)
14
N
N
Figure 9.5
A new family of chromonic mesogens based on triphenylene that is
surrounded by an annulus of alkyl chains terminated by charged imidazolium groups.
Aida and his coworkers synthesized and reported (see details in Part
II, ref. [59]) a new class of chromonic mesogens (Figure 9.5) based on
triphenylene derivative that carries parai nic side chains terminated by
charged imidazolium group that form an LC phase with a bicontinuous
cubic mesophase and a hexagonal M phase over a wide temperature range.
It was demonstrated that both Col
h
(columnar hexagonal phase) and Cub
bi
(bicontinuous cubic) LC mesophase were composed of π-stacked TP col-
umns. Both π-stacking of discotic core and interionic interactions of imid-
azolium-based ionic liquid pendants (with shorter and longer spacers)
determine the phase diagram. h ese materials are very attractive as they
would be capable of forming long-lived charge carriers and are expected to
achieve an exciting range of novel electro-optic properties.
9.2.2
Applications of Chromonic Mesophases
Chromonic systems are self-assembled and self-organized through weak
noncovalent interaction, such as π-π interactions, into ordered supra-
molecular architectures. h erefore, by controlling supramolecular enti-
ties and rational design of chromonic systems new functional materials
and devices can be generated. h ey have shown promise for new applica-
tions, such as optically anisotropic dried i lms, polarizers, micropattern-
ing, organic electronics and functional materials for nanofabrication.
Below we describe some potential applications of discotic chromonic
mesophases.
