Biomedical Engineering Reference
In-Depth Information
1.0
1.0
E = 1 Volt step @ 1/2 Hz
E = 2 Volt step @ 1/2 Hz
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0.0
0.0
−
0.2
−
0.2
−
0.4
−
0.4
−
0.6
−
0.6
−
0.8
−
0.8
−
1.0
−
1.0
2
34567
8
2
3
4
5
6
7
8
Time (sec)
Time (sec)
1.0
1.0
E = 3 Volt step @ 1/2 Hz
E = 4 Volt step @ 1/2 Hz
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0.0
0.0
−
0.2
−
0.2
−
0.4
−
0.4
−
0.6
−
0.6
−
0.8
−
0.8
−
1.0
−
1.0
2
34567
8
2
34567
8
Time (sec)
Time (sec)
SAMPLE-3
FIGURE 3.20
Current responses to step voltages of 1, 2, 3, and 4 V for Taguchi sample 3.
under a given voltage of 1.2 V
rms
is in the general order of the ones generated with
counter-ions: Li
+
>> Na
+
> (K
+
, Ca
++
, Mg
++
, and Ba
++
) > (H
+
, TBA, and TMA). This
fact was observed for Nafion-based IPMNC and Flemion-based IPMNC (Onishi et
al., 2000).
In the set of Li
+
, Na
+
, and K
+
, one should realize that Li
+
is undoubtedly the
smallest bare ion in the set (its radius, r[Li
+
] < r[Na
+
] < rK
+
]) but has the lowest
mobility (the drag to its motion through the solution, u[Li
+
] < u[Na
+
] < u[(K
+
])
(Moor, 1972; Atkins, 1982; Moor et al., 1992; Gebel et al., 1987; Komoroski et al.,
1982).
All these observations could be due to the hydration phenomena (a tightly held
sheath of water molecules bound under the electric field caused by cations/anions).
