The concentration dependent cooperative friction coefficient of dilute polymer solutions at the theta point

Cherayil, BJ and Freed, KF (1996) The concentration dependent cooperative friction coefficient of dilute polymer solutions at the theta point. In: Journal of Chemical Physics, The, 104 (15). pp. 5983-5996.

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Abstract

We combine multiple scattering and renormalization group methods to calculate the leading order dimensionless virial coefficient k(s) for the friction coefficient of dilute polymer solutions under conditions where the osmotic second virial coefficient vanishes (i.e., at the theta point T-theta). Our calculations are formulated in terms of coupled kinetic equations for the polymer and solvent, in which the polymers are modeled as continuous chains whose configurations evolve under the action of random forces in, the velocity field of the solvent. To lowest order in epsilon=4-d, we find that k(s) = 1.06. This result compares satisfactorily with existing experimental estimates of k(s), which are in the range 0.7-0.8. It is also in good agreement with other theoretical results on chains and suspensions at T-theta. Our calculated k(s) is also found to be identical to the leading order virial coefficient of the tracer friction coefficient at the theta point. We discuss possible reasons for the difficulties encountered when attempting to evaluate k(s) by extrapolating prior renormalization group calculations from semidilute concentrations to the infinitely dilute limit. (C) 1996 American Institute of Physics.

Item Type:	Journal Article
Publication:	Journal of Chemical Physics, The
Publisher:	American Institute of Physics
Additional Information:	Copyright of this article belongs to American Institute of Physics.
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	13 May 2011 05:09
Last Modified:	13 May 2011 05:09
URI:	http://eprints.iisc.ac.in/id/eprint/37628

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