Entangled system many-chain approach

This is in contrast to the stage of development of model theories where the many-entangled-excluded-volume-chain problem still has to be overcome, although promising approaches exist. In particular it will turn out that the theoretical concepts available for this sort of system are unable to describe many experimental details quantitatively. On the other hand, predictions of all model theories referred to in this context will be shown to be compatible with certain experimental findings provided that the sample and measuring conditions are adapted to the scenarios that were anticipated in the theoretical derivations. 

In the polymer problem, the validity of this equation is not obvious since the des ption of the polymeric system by c disregards the chain connectivity and, therefore, neglects the entanglement effect. However, as far as the dynamics in the short time-scale is concerned, this will not be a serious problemt since, as we shall discuss later, the topological constraints are not important in the short time-scale dynamics. Indeed it will be shown that the initial slope in the dynamical structure factor is correctly described in this approach. In the long time-scale, on the other hand, the validity of eqn (5.88) is not clear, and it may well be that the theory has to be modified in future. Fortunately, many experiments related to concentration fluctuations are concerned with the short time-scale motion, so that it is worthwhile to pursue the idea in detail. 

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