Cerf-Peterlin Theory

Internal Viscosity and Cerf-Peterlin Theory. The concept of the internal viscosity was first employed by Kuhn and Kuhn 120) in an attempt to describe the shear-rate dependent viscosity with a dumbbell model or a bead-spring model with N = 1. They assumed that a force proportional to the relative velocity of the beads is exerted on the bead from the connector (spring) in addition to the spring force which is proportional to the relative position of the beads. This force intrinsic to the polymer molecule is compared with the frictional force from the viscous medium and is associated with the term internal viscosity . 

To say nothing about the different equivalent forms of the theory of the Brownian motion that has been discussed by many authors (Chandrasekhar 1943 Gardiner 1983), there exist different approaches (Rouse 1953 Zimm 1956 Cerf 1958 Peterlin 1967) to the dynamics of a bead-spring chain in the flow of viscous liquid.1 In this chapter, we shall try to formulate the theory in a unified way, embracing all the above-mentioned approaches simultaneously. Some parameters are used to characterise the motion of the particles and interaction inside the coil. This phenomenological (or, better to say, mesoscopic) approach permits the formulation of overall results regardless to the extent to which the mechanism of a particular effect is understood. 

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