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10
2
L
2
98°C
ELP
10
1
10
0
H
2
60°C
EHP
Pn3m
ECP
25°C
10
-1
0
1
2
3
4
q [nm
-1
]
Figure 5.4
Comparison of SAXS curves of the dispersed and the nondispersed fully
hydrated sample with excess water (40 wt % water) at three temperatures (de Campo
et al., 2004): The thick lines correspond to the dispersion and the thin lines to the bulk
phase. The intensities were normalized by the respective MLO concentration.
phase transition from H
2
to L
2
seemed to take place already at slightly lower
temperatures in the dispersion (de Campo et al., 2004). This good agreement
between the results obtained for both the dispersed and the nondispersed
systems shows that the internal structure of the dispersions at each tempera-
ture actually corresponded to the equilibrium structure of MLO with excess
water. Moreover, only a small part of F127 seemed to be incorporated into
the internal structure of the dispersed particles. In other words, F127 was very
effective as a stabilizer and covered mainly the outer surface of the emulsifi ed
particles.
The temperature-induced transition from cubosomes to hexosomes was
observed by cryo-TEM (Figs. 5.2a and 5.2b). At 25°C, the fast Fourier trans-
forms (FFTs) of the internal structure of the particles were compatible with
the cubic Pn3m symmetry. At a higher temperature (55°C), the hexosome
particles displayed internal arrangements of a hexagonal symmetry (arrows in
Fig. 5.2c) and/or curved striations (Figs. 5.2c and 5.2d).
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