The Excluded Volume Effect in a Semi-Dilute Solution

7 The Excluded Volume Effect in a Semi-Dilute Solution 

First of all, we need to know the value of c for a semi-dilute solution. When c = c, the average segment density in the whole solution becomes equal to the average segment concentration inside each coil (see Section 6.6). 

Therefore, taking into account the excluded volume, we get  

Since N 1, the threshold density c is fairly small (just as it was for an ideal polymer solution see (6.14)). Thus the semi-dilute regime is appropriate for a wide range of concentrations. 

Now we need to calculate the value R in a semi-dilute solution. 

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