Diffusion of Polymer Chains in a Fixed Network

S Diffusion of Polymer Chains in a Fixed Network Although the tube model and the reptation model were originally developed to explain the diffusion of polymer chains in concentrated solutions and melts, we can use it more naturally for the motion of polymer chains in a fixed network, for instance, a cross-linked network of polymer swollen in a good solvent. In the fixed network, the constraint release is absent. Therefore, we should be able to observe the reptation without being compromised. 

The cross-hnked network of polymer is called a gel. In the absence of the cross-linking, the swollen gel would form a solution. A probe polymer is added to the gel matrix, and the motion of the probe chains is traced by using DLS. The solvent needs to be isorefractive with the gel matrix to allow one to selectively detect the 

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