Variation of the screening length with concentration

When the concentration p increases, the screening length decreases, and this is one of the most revealing facts of the structure of good semi-dilute solutions. 

For q c z 2.6, the structure function of the chains has about the same behaviour as the form function of a chain. 

Theory defines the Kuhnian overlap length by the equality [see (15.4.34)] 

In reality, the experiment gives the average A2i and Afw, but we shall neglect poly dispersion effects here. It is necessary to check that has the required 

Let us determine the value of the coefficient f = fB/ k. The definitions given above show that 

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