184
S. Cerveny and J. Swenson
than for PVME. In the next two sections, we will analyze how the characteristics of
the water dynamics changes under isothermal crystallization of the different systems
here studied.
6 The Dynamics of Water Solutions After Isothermal
Crystallization
Now, we analyze the dynamics of the semi-crystalline materials concentrating on the
water and ice relaxations. Figure 11 shows the dielectric spectra of 3PG with c w = 50
wt% in the amorphous (Fig. 11a) and semi-crystalline states (Fig. 11b). The semicrystalline state was obtained by keeping T cryst = 200 K during t cryst = 8 h (480 min)
and no change in the glass transition temperature was observed. Similar results were
obtained for the other water concentrations and for crystallization temperatures for
which T g remains the same. As mentioned above, the intensity of the dielectric loss
of water in the amorphous state (a) is smaller than in the semi-crystalline mixture (b)
since a portion of the amorphous water turns into ice during isothermal crystallization. The fitting procedure was already explained in Fig. 9 for 3PG solutions. This
procedure was also used to fit the data of PVP and PVME solutions.
Figure 12 shows the shape factors and relaxation strengths for the ice and water
relaxations in the amorphous and semi-crystalline states of this sample (3PG, c w =
10
-1
10
1
10
3
10
5
0.01
0.1
1
10
10
-1
10
1
10
3
10
5
0.01
0.1
1
10
(b)
3PG, c w = 50 wt%
Semi-crystalline sample
150 K
180
191
165
ε´´
f [Hz]
200
(a)
3PG, c w = 50 wt%
Amorphous sample
150 K
180
191
165
ε´´
f [Hz]
200
Fig. 11 a Loss component, ε , of the complex permittivity, ε*(f), of the amorphous 3PG—water
solution with c w = 50 wt% at different temperatures. The lines through the data points correspond
to least-square fits to a superposition of two Cole–Cole functions. b Same as in (a), but after
isothermal crystallization at T cryst = 200 K during t cryst = 8 h. The solid lines through the data
points correspond to least-square fits to a superposition of three Cole–Cole functions
S. Cerveny and J. Swenson
than for PVME. In the next two sections, we will analyze how the characteristics of
the water dynamics changes under isothermal crystallization of the different systems
here studied.
6 The Dynamics of Water Solutions After Isothermal
Crystallization
Now, we analyze the dynamics of the semi-crystalline materials concentrating on the
water and ice relaxations. Figure 11 shows the dielectric spectra of 3PG with c w = 50
wt% in the amorphous (Fig. 11a) and semi-crystalline states (Fig. 11b). The semicrystalline state was obtained by keeping T cryst = 200 K during t cryst = 8 h (480 min)
and no change in the glass transition temperature was observed. Similar results were
obtained for the other water concentrations and for crystallization temperatures for
which T g remains the same. As mentioned above, the intensity of the dielectric loss
of water in the amorphous state (a) is smaller than in the semi-crystalline mixture (b)
since a portion of the amorphous water turns into ice during isothermal crystallization. The fitting procedure was already explained in Fig. 9 for 3PG solutions. This
procedure was also used to fit the data of PVP and PVME solutions.
Figure 12 shows the shape factors and relaxation strengths for the ice and water
relaxations in the amorphous and semi-crystalline states of this sample (3PG, c w =
10
-1
10
1
10
3
10
5
0.01
0.1
1
10
10
-1
10
1
10
3
10
5
0.01
0.1
1
10
(b)
3PG, c w = 50 wt%
Semi-crystalline sample
150 K
180
191
165
ε´´
f [Hz]
200
(a)
3PG, c w = 50 wt%
Amorphous sample
150 K
180
191
165
ε´´
f [Hz]
200
Fig. 11 a Loss component, ε , of the complex permittivity, ε*(f), of the amorphous 3PG—water
solution with c w = 50 wt% at different temperatures. The lines through the data points correspond
to least-square fits to a superposition of two Cole–Cole functions. b Same as in (a), but after
isothermal crystallization at T cryst = 200 K during t cryst = 8 h. The solid lines through the data
points correspond to least-square fits to a superposition of three Cole–Cole functions