Chemistry Reference
In-Depth Information
tinuous cubic structures at the liquid crystalline state [83]. Photopolymer-
izations of
23
in liquid crystalline state proceed with preservation of the
ordered supramolecular architectures and maintenance of the lattice dimen-
sions. Photopolymerization of
23
in the bicontinuous cubic liquid crystalline
state gives rise to a 3D ordered nanostructure, while in the hexagonal colum-
nar liquid crystalline state it produces a 2D ordered nanostructure that in
aqueous solution can be dispersed into individual nanofibers with a uniform
diameter. The covalent stitching of reactive rod segments within the ordered
state by photopolymerization offers a strategy to construct shape-persistent
organic nanomaterials with well-defined size and shape, which potentially
have applications in macromolecular electronics, nanoreactors, and hybrid
nanomaterials.
A strategy to control the aggregation structure assembled from a rod
building block may be accessible by incorporation of side groups into a rod
block [84]. The side groups could lead to loose packing of the extended rod
segments, which may modify the resulting supramolecular structure. A coil-
rod-coil molecule (
24
) consisting of five biphenyl units connected through
ether linkages as a rod block and PPO coils with the number of repeating
units of 17, self-assembles into hexagonal perforated layers stacked in ABAB
order in the melt. In contrast, a coil-rod-coil molecule (
25
) containing methyl
Fig. 15
Self-assembly of coil-rod-coil molecule
25
into the hexagonal perforated lamellar
structure and subsequent conversion to hexagonal closed-packed bundles
Search WWH ::
Custom Search