Table 2 Influence of the freeze–thaw treatment on the solutions of polymeric precursors capable
of forming physically crosslinked gels
Precursor
Precursor
concentration in
the feed (wt%) Solvent
Temperature of
the gelation
process (
C)
Appearance of the
samples after the gel
formation process
References
Agar-agar
0.5
Water +20
Rather weak gel
[12]
À10
Sponge-like cryogel
1.0
+20
Weak gel
À10
Sponge-like cryogel
Agarose
g-temperature brand)
0.5
Water +20
Jelly-like system
[7]
À20
Weak sponge-like
cryogel
Amylopectin
1.0
Water +18
Thin precipitate
[98]
À18
Non-spongy cryogel
5.0
+18
Very viscous paste
À18
Non-spongy rigid
cryogel
Gelatin
(A-type)
0.5
Water +20
Liquid
[12]
À10
Sponge-like cryogel
1.0
+20
Liquid
À10
Sponge-like cryogel
1.5
+20
Very weak gel
À10
Sponge-like cryogel
Locust-bean
gum
0.3
Water +18
Turbid liquid
[100, 115]
À30
Spongy cryogel
3.0
+18
Viscous opaque paste
À30
Non-spongy cryogel
Maltodextrin
a
12.5
Water +18
Opalescent liquid
[101]
À24
Spongy weak cryogel
Oat β-glucan
3.0
Water +22
No gel formation
[145, 146]
À18
Spongy cryogel
Potato starch
2.5
Water +18
Rather weak starch
gel
[147]
À18
Sponge-like cryogel
PVA
b
15.0
Water +25
Mechanically weak
gel
[13]
PVA
c
10.0
Water +20
Liquid
[12, 92]
À10
Non-spongy cryogel
À20
Rather rigid cryogel
16.0
+20
Liquid
+2
Very weak gel
À10
Rigid cryogel
À20
Rigid cryogel
13.0
DMSO ΔT ¼ +1.6
Liquid
[12]
ΔT ¼ À28.4
Rather rigid cryogel
a
Molecular weight 8 kDa
b
Duration of the incubation at gelation temperature 12 days
c
Molecular weight 69 kDa
72
V.I. Lozinsky and O. Okay