Chemistry Reference
In-Depth Information
10
1
α
= 75,
β
= 100
α
= 75,
= 0
β
α
= 19,
β
= 100
= 19,
= 0
α
β
0
1
2
3
4
q [nm
-1
]
Figure 5.16
Effect of DGMO content on TC-loaded aqueous MLO-based dispersions
at 25°C with
α
ratios of 19 and 75. The scattering curves of the DGMO-free dispersions
100). The intensities have been
shifted by a constant arbitrary factor for the sake of visibility. [Reprinted from Yaghmur
et al. (2006b) .]
(
β
=
0) are compared to those containing DGMO (
β
=
Fig. 5.16), the replacement of a relatively high amount of MLO by DGMO
(
19)] signifi cantly enlarged the H
2
structure as indicated by
the peaks in the scattering curve being shifted to lower angles. However, the
DGMO concentration was still not effi cient enough to tune back the internal
structure to the V
2
phase. The enhanced water solubilization capacity was the
underlying reason for this signifi cant change in the internal nanostructures of
these oil-loaded dispersions in the presence of DGMO with its bulky hydro-
philic group. For instance, increasing the DGMO content in the oil-loaded
nondispersed phase (also with
β
=
100, for
α
=
0 to 100 signifi cantly increased
the content of solubilized water in the H
2
phase from approximately 25 to
35 wt % without any structural transition. Furthermore, the corresponding
structure parameter,
a
, was much larger than that of the ternary MLO-TC-
water system at the same water content (Yaghmur et al., 2006b). We also found
a good structural agreement between this fully hydrated bulk phase and the
dispersed H
2
structure (Yaghmur et al., 2006b). This result was similar to those
from previous studies with respect to the stabilization of hexosomes (Gustafs-
son et al., 1996; Larsson, 2000) indicating that F127 did not infl uence the
internal H
2
structure.
It is also noteworthy that DGMO signifi cantly increased the temperature
for all structural transitions (Yaghmur et al., 2006b). For instance, the H
2
α
=
19 from
β
=
→
L
2
transition temperature of the dispersion with
6 increased from approxi-
mately 86 to 92°C when MLO was replaced by MLO-DGMO mixture.
α
=
Search WWH ::
Custom Search