Zimm Model in the Good Solvent

4 Zimm Model in the Good Solvent The Zimm model we used for the theta chains needs a small modification when we apply it to the chains in the good solvent. We must give up the numerical coefficients but can stiU obtain the exponents that agree with experimental results. 

Second, the force constant ki needs some change because the Gaussian chain does not describe the conformation of the real chain. It can be obtained from 

With these modified and Iq, q, follows the same equation as in the Zimm model in the theta solvent. 

The center-of-mass diffusion coefficient is obtained from Eqs. 3.152 and 3.179 as 

The Zimm model for the good solvent successfully describes the experimentally observed dependence Dq M, ti and t,/Tj r . 

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