Polyelectrolytes: Theory, Properties and Applications

Structural Properties and Phase Behavior ... 15

Figure 6. Symmetric partially charged DCPs : effects of ionic strength. a) qR^22 mg(LHS

y-axis) and Saa(qm) (RHS y-axis) vs salt, b) Saa(q) vs qR^22 g for different values of salt.

Here we used x = 1/2,  = 0.3, f = 0.2, N = 100, as = 0, bs = 0.5, ab = 0.15.

The conditions of microphase separation are reached when the parameter
ab takes the critical value c and the peak height Saa(qm) becomes infinite.
This criticality condition is obtained by letting D of Eq. 4 be equal to zero
which yields the general result for arbitrary x

(^1112)
c as bs m am bs bm as m
1 1 221
1 1 1
S S S f
   
                  
        

, (17)

0 5 10 15

0.6

0.8

1.0

1.2

1.4



salt

S

aa

(q

)

q

2

R

2

g

f =0 (neutral)

salt= 0.05

0.1

0.3

4.0

4.5

5.0

b)

q

2 m

R

2 g

a)

0.0 0.1 0.2 0.3

1.0

1.2

1.4

Benmouna et al. Figure 6

S

aa

(q

m

)