Chemistry Reference
In-Depth Information
(a)
80
70
60
50
40
30
20
10
0
Hex
EME
50
60
70
80
90
δ
-value
δ
= 70.5
74 min
64 min
54 min
44 min
34 min
24 min
14 min
4 min
Hex
EME
(
δ
84 +
δ
57)/2
0.0
0.5
1.0
1.5
2.0
2.5
δ
= 57
δ
= 84
100
1. 0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Experimental scattering curve (40−42 min)
Scattering curve of sample
(b)
(c)
δ
=84
δ
= 84
δ
=57
δ
= 70.5
Scattering curve of sample
= 57
δ
Scattering curve of sample
= 70.5
Fit to experimental scattering curve
δ
Fd3m
EME
10
Hex
1
FItted Curve
0
1000
2000 3000
Time (s)
4000
5000
0.0
0.2
0.4
0.6 0.8
1.0
1.2
1.4
1.6
1.8
2.0 2.2 2.4
q [nm
−1
]
I(q)
mixture
= X
phase1
I(q)
phase1
+ X
phase2
I(q)
phase2
+ X
phase3
I(q)
phase3
Figure 6.7
Transfer kinetics among mixed ISAsomes: (a) Time-resolved three-
dimensional stack plot of SAXS scattering curves during material exchange of H
2
- and
EME-based ISAsomes at 25°C. The decrease in intensities of the H
2
and EME phase
signatures indicates their disappearance, while the gradual increase in intensity of the
Fd3m signature indicates its formation. The compositional change (δ value) is shown
schematically as an inset on the right. (b) SAXS scattering curves of various nanostruc-
tures are indicated. The experimental data were fi tted to the master curve, which was
calculated by using the formula shown below the graphs for
I
(
q
)
mixture
. It was fi tted as
a weighted sum of the scattering curves of the single phases [
I
(
q
)
phase1
,
I
(
q
)
phase2
, . . . ]
using a least-squares algorithm (Moitzi et al., 2007). The weights of the best fi t (
X
phase1
,
X
phase2
, . . .) can be interpreted as fractions of the corresponding phases in the investi-
gated samples. By this procedure one can follow the time-resolved changes in concen-
tration of the different phases shown in (c).
kinetic events of disappearing and newly forming ISAsome nanostructures
(Fig. 6.7 c).
The hexagonal phase exhibits the sharpest peak in its SAXS scattering
curves (Fig. 6.7b); the transfer kinetics were followed by tracking the changes
in this peak intensity. The corresponding rate constant was then calculated
by fi tting the curve to a single exponential decay, which is characteristic for a
Search WWH ::
Custom Search