Biomedical Engineering Reference
In-Depth Information
2
2
for CA4.5, 1924 m
/g for CA4.8, and 1482 m
/g for CA5.2 by means of
N
adsorption/desorption at 77 K. The porous structure properties
determined by nitrogen adsorption are shown in Table 3.3.
2
Table 3.3
The porous structure properties determined by nitrogen
adsorption
a
b
V
mic
(cm
3
/g�
V
meso
(cm
3
/g�
(cm
3
/g�
V
mic
S
BET
(cm
2
/g�
Sample
CA4.1
1420 ± 17 0.63 ± 0.03 0.40 ± 0.03 0.46 ± 0.02
CA4.5
1798 ± 15 0.76 ± 0.04 0.56 ± 0.02 0.53 ± 0.02
CA4.8
1924 ± 26 0.86 ± 0.08 0.96 ± 0.05 0.63 ± 0.03
CA5.2
1482 ± 18 0.60 ± 0.02 0.46 ± 0.03 0.40 ± 0.01
a
Note:
BET surface area (
S
) and the total micropore volume (
V
) as calculated by D-R Eqs.
BET
mic
b
(3.5) and (3.6); micropore volume (
V
)and the total mesopore volume (
V
) as calculated by
meso
mic
the BJH method if the macropores (pore size larger than 50 nm) are ignored.
Hydrogen sorption measurements were performed at cryogenic
temperature (77 K), with results presented in Fig. 3.8.
Figure
3.8
Hydrogen sorption measurements were performed at
cryogenic temperature (77 K). The inset is the maximum
hydrogen uptake vs. CAs derived from different pH pre-
cursors: (a) CA4.1, (b) CA4.5, (c) CA4.8, and (d) CA5.2.
The maximum hydrogen uptake increased from 4.18 wt.% for
CA4.1, to 4.54 wt.% for CA4.5, and reached a maximum value of
