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(a)
(c)
(b)
(d)
Figure 5.2
Cryo-TEM images of a dispersion consisting of 4.625 wt % MLO, 0.375 wt
% F127, and 95.0 wt % water (de Campo et al., 2004). At 25°C [images (a) and (b)],
the internal structure of the cubosome particle [inset in image (b)] showed a hexagonal
arrangement with interplanar distances
d
of approximately 6 nm. This was compatible
with a cubic structure of Pn3m symmetry with a lattice parameter,
a
, of 8.5 nm (a good
agreement with the SAXS analysis). At 55°C [images (c) and (d)], certain of the nano-
structured hexosome particles exhibited an internal hexagonal symmetry [arrows in
image (c)], whereas others exhibited curved striations [stars in images (c)].
particles with nanostructured interiors as shown in the cryo-TEM (transmis-
sion electron microscopy) images in Figure 5.2. The coexistence of cubosomes
and vesicles (Figs. 5.2a and 5.2b) has also been observed in previous studies
on dispersed monoglycerides (Barauskas et al., 2005; Gustafsson et al., 1996;
Larsson, 2000 ).
Figure 5.3 shows the temperature-dependent SAXS curves of the aqueous
dispersion. It is clear that the internal structures of this MLO-based dispersion
underwent a transition from Pn3m, denoted Q
224
(cubosomes, emulsifi ed cubic
phase, ECP), via H
2
(hexosomes, emulsifi ed hexagonal phase, EHP), to the
fl uid L
2
phase (emulsifi ed L
2
phase, ELP) as the temperature was increased.
The ELP was of particular interest since it had to our knowledge never before
been described in the literature. This emulsion consisted of submicron-sized
droplets with a nanostructured, nonviscous fl uid isotropic micellar water-
MLO - rich interior and had no long - range order.
Figure 5.4 shows SAXS patterns for the MLO dispersion (thick lines) as
well as the corresponding nondispersed fully hydrated sample (thin lines) at
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