Synthesis and Alignment of Nanostructured Materials Using Liquid Crystals - Self-Assembled Supramolecular Architectures: Lyotropic Liquid Crystals - page 191

Figure 7.1 Presentation of main types of nematic and positional ordered thermotropic
LC phases: N u = uniaxial nematic phase, N D = discotic nematic phase, N Col = columnar
nematic phase, L a = lamellar or smectic A phase, SmA = smectic A phase, SmC = smectic
C phase, SmC a P a = anticlinic antiferroelectric polar smectic C phase, Col r = rectangular
columnar phase, Col ob = oblique columnar phase, Col h = hexagonal columnar phase,
Cub V = bicontinuous cubic phase, and Cub I = micellar cubic phase (space groups are
in italics). [Adapted from Hegmann et al., (2007).]
and a solvent (usually water) (Hyde, 2001; Hyde et al., 1997). The addition of
a solvent such as water to the amphiphilic molecules selectively hydrates the
hydrophilic moiety of each molecule (ionic or neutral), avoiding the hydro-
phobic regions. This hydrogen bonding between the solvent (e.g., water) and
the polar moiety of the solute, and the interplay (van der Waals interactions)
between the hydrophobic moieties drives the molecules to self-assemble,
thereby segregating the hydrophobic chain away from contact with the water.
As a result, the strongly hydrogen-bonded polar moiety is frozen, while the
apolar, hydrophobic part is molten (Larsson, 1989; Larsson et al., 1980).
In this case, the degree of order of the different phases depends on the
components' composition; however, they are also infl uenced by other external
parameters such as temperature and pressure (Seddon, 1990; Tiddy, 1980).
The LLC systems may exhibit a rich polymorphism of structures depending
on the molecular shape/packing preferences of the LLC molecules (Fig. 7.2;