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Normal phases (type 1)
Inverted phases (type 2)
H
II
T,
interface
curvature,
Pm
3
n
(V
I
)
Fm
3
m
(I
I
)
V
II
CPP
Fd
3
m
(I
II
)
Ia
3
d
(V
I
)
L
α
Im
3
m
(V
I
)
cmc
I
II
H
II
V
II
L
α
V
I
H
I
I
I
Water content
CPP = 1
CPP > 1
CPP < 1
Figure 7.2
Hypothetical lyotropic binary phase diagram where phase transitions can
be induced by varying water content or temperature. The indicated mesophases are:
L
α
=
lamellar, Ia3d, Pn3m, or Im3m
=
direct and inverted bicontinuous cubic (V
I
and
V
II
, respectively), Fd3m
direct and inverted micellar/discontinuous cubic (I
I
and I
II
,
respectively), and H
I
and H
II
=
direct and inverted hexagonal phase. The cmc (far right
in the fi gure) represents the critical micellar concentration of surfactant from which it
creates micelles.
=
Israelachvili et al., 1976; Larsson et al., 1980) and interfacial curvature energy
considerations (Duesing et al., 1997; Templer et al., 1998; Vacklin et al., 2000).
The major mesophases of the LLCs are lamellar (L
α
); normal and reverse
hexagonal (H
I
and H
II
); and cubic bicontinuous and discontinuous structures
(V
I
, V
II
and I
I
, I
II
, respectively) (Fig. 7.2 ).
Thermotropic and lyotropic LC phases have various properties that make
them ideal for use as advanced materials for potential nanomaterial applica-
tions (Miller et al., 1999). Since LCs combine order and mobility at the molecu-
lar, nanoscale level, their ordered structures can respond to external fi elds or
to chemical changes as desired for specifi c applications such as controlled
release (Douglas et al., 2008).
Their highly uniform, porous nanoscale architectures can be used also to
incorporate, crystallize, or synthesize (growing nanostructured) hydrophobic
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