Polyelectrolytes: Theory, Properties and Applications

20 F. Benmouna, R. Kaci and M. Benmouna

Figure 10. Critical parameter for microphase separation c of non symmetric partially
charged DCPs : effects of composition x, f and salt for a) c vs x at different values of f
(salt = 0), b) c vs x at different values of salt (f = 0.1). Here we used  = 0.3, N = 100,
as = 0, bs = 0.5, ab = 0.15.

The phase diagrams of Figure 10 show c vs x for different values of f

without salt (panel a) and different values of salt, keeping f constant (panel b).
This behavior confirms the trends observed in Figure 9 and the impact of
dissymmetry induced compatibility enhancement combined with that of long
range coulomb repulsion. Increasing the degree of ionization f (panel a)
reinforces those effects while a stronger ionic strength (panel b) inhibits them.
For small x (x < 0.2), the critical parameter c increases slightly with f (slight
compatibility increase) but for relatively high x (x > 0.6), c goes up
substantially signaling a high compatibility enhancement due to long range
coulomb interaction. The added salt acts in the opposite direction by inducing

0.0

0.2

0.4

0.6

0.8 salt = 0

0.25

0.15

0.2

f=0

0.1



c

x

a)

0.1 0.2 0.3 0.4 0.5 0.6 0.7

0.0

0.1

0.2

0.3

0.4

Benmouna et al. Figure 10

0.15, 0.2

f = 0.1



c salt= 0

0.02

0.1

b)