Fig. 1 (a–c) Optical micrographs of 2-mm-thick disks of chitosan cryogels formed in moderately
frozen aqueous solutions using glutaraldehyde as a crosslinker at À10 (a), À15 (b), and À30
o
C (c).
(From [10] with permission from Springer)
Table 1 Data on the quantitative analysis of microscopic images for the crosslinked chitosan
cryogels formed at different negative temperatures
Temperature of cryogel synthesis (
C)
D n (μm)
a
D w (μm)
b
k
c
À10
57.4
70.1
1.22
À15
72.3
87.0
1.20
À30
44.3
56.0
1.26
From [10] with permission from Springer
a
Number-average pore diameter: D n ¼ (∑(N i Á Á Á D
3
i ) : ∑ N i )
1/3
; the overall number of test objects
in the micrograph is ∑N i
b
Weight-average pore diameter: D w ¼ {∑(N i Á Á Á D
6
i ) : ∑ (N i Á Á Á D
3
i )}
1/3
c
Coefficient of polydispersity: k ¼ D w :D n
56
V.I. Lozinsky and O. Okay