Turbidity and Rayleigh Ratio

If lo and I are the intensities of the beam before and after passing through a length ( of the medium, they ean be related in terms of Beer s law for the absorption of hght as follows (Rudin, 1982)  

Noting that 1 = 1 - Is, where Is is the total intensity of hght that is scattered by the solution, Eq. (4.67) may be written in the form (Allcock and Lampe, 1990)  

The value of the product of the de nite integrals is 16 r/3 (Rudin, 1982 Allcock and Lampe, 1990), so that we obtain the following relationship involving turbidity and the total scattered intensity  

This expression provides us with a way to determine molecular weights of polymers from light scattering of polymer solutions as shown below. Moreover, a comparison of Eqs. (4.74) and (4.63) shows that the relationship between the turbidity and the Rayleigh ratio is 

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