Functional Liquid-Crystalline Polymers for Ionic and Electronic Conduction - Liquid Crystalline Functional Assemblies and Their Supramolecular Structures - page 160

and indium tin oxide with 3-(aminopropyl)triethoxysilane, and orientation
parallel to a glass surface by mechanical shearing. The polymerized film in the
solid state shows ionic conductivities in the order of 10 -6 Scm -1 in the direc-
tion parallel to the columnar axis at around 50 ◦ C. The value is approximately
300-times higher than those perpendicular to the axis.
Supramolecular approaches [5, 7, 20-22] are also effective for ion conduc-
tion in polymers. Ikkala and ten Brinke prepared the complex of polystyrene-
block -poly(4-vinylpyridine) (PS- b -PVP) and oligo(ethylene oxide)sulfonic
acid 11 [71, 72]. The polymer self-assembles into lamellar nanostructures
consisting of glassy hydrophobic polystyrene and hydrophilic PEO layers,
as shown in Fig. 11. When LiClO 4 is dissolved in the polymer composites,
lithium ions are complexed and transported in the hydrophilic PEO layers,
resulting in high ionic conductivities on the order of 10 -6 Scm -1 at ambient

temperature.
It is interesting that proton conduction is also available in the polymer
composites consisting of a similar polymer, toluenesulfonic acid, and 3-penta-
decylphenol ( 12 ) as shown in Fig. 11 [73]. They form hierarchical lamellar
nanostructures. The PS and PVP blocks are segregated at a larger scale. In
the PVP blocks, additional lamellar substructures are formed through the
nano-segregation of the alkyl chains and the PVP main chains. Monodomain
orientation on the larger scale is achieved by applying shear force, resulting in
anisotropic proton conduction [74].
Wiesner reported a new class of LC ion-conductors capable of switch-
ing ionic conduction, as shown in Fig. 12 [75-77]. The molecules with PEO
block and dendritic block 13 show several low dimensional nanostructures.

Fig. 12 Fan-shaped LC molecules consisting of dendritic alkyl chains and a PEO moiety
at the focal point