CH1012
L1 /
‹#›
L1 /
11
3) Effect of charge
Z of counterions
(10-3 M)
eg.
Na+, Ba2+, Al3+
DOUBLE LAYER EFFECTS
1 10-3 M
2 10-2 M
3 10-1 M
1
Z = 1
2
Z = 2
3
Z = 3
distance
Y
distance
Y
distance
Y
1
1
2
2
3
3
Graph 1 Graph
2 Graph 3
Diffuse Double
Layer Model (Gouy & Chapman)
1) Exponential decay of electric pot. Y with
distance of an ion from the charged surface.
distance of an ion from the charged surface.
2) Effect of concentration of
univalent
counter- and co-ions eg. Na+Cl-
counter- and co-ions eg. Na+Cl-
For this reason
Al3+ is chosen to coagulate blood.
Al3+ is chosen to coagulate blood.
