Dynamic models of macromolecules

Features of the dynamic behavior of polymers have been explained based on the idea of Brownian motion of the monomeric segments, which we detail in the following section. Here we present briefly the prominent treatises of conformational motions of flexible polymers in dilute solutions. These are the Rouse and the Zimm models. 

The Rouse model assumes unperturbed chains in the free-draining limit (the limit of no hydrodynamic interactions between monomers) that can be represented as a set of beads connected along the chain contour. The Zimm model, in addition to the Rouse model features, takes into account the hydrodynamic interaction of the beads. 

For concentrated solutions and melts the interactions of different chains take over the dynamic behavior. The reptation theory, based on the ideas of reptation and entanglements, first discussed by de Gennes, describes the behavior of these systems fairly well. 

The dynamic behavior of macromolecules can be explained by adopting the time correlation functions of the equilibrium fluctuations of the chain end-to-end vectors, CRR(t) (for a precise definition of correlation 

For systems in homogeneous environments and in the absence of cross-correlations between different chains, crr 1) is reduced to the autocorrelation function of the end-to-end vector. 

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