Other small-scale fluctuations and their effects on the segmental motion

4 Other small-scale fluctuations and their effects on the segmental motion 

Due to the small-scale fluctuations around the primitive path, the actual dynamics of the Rouse segment in a network is much more complicated t n that described in Section 6.3.2. As an example, let us consider the mean square displacement of a Rouse segment. 

The precise calculation of 0 (O is difficult, but its characteristic features can be inferred easily. 

This formula is correct when the average displacement is much less than the tube diameter. Let be the time at which the segmental displacement becomes comparable to a  

The time t denotes the onset of the effect of tube constraints for t t , the chain behaves as a Rouse chain in free space, while for r t the chain feels the constraints imposed by the tube, 

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