Polyelectrolytes Revisited: Reliable Determination of Intrinsic Viscosities

✍ Scribed by Bernhard A. Wolf

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 157 KB
• Volume: 28
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.200600650

✦ Synopsis

Abstract

The linear extrapolation of (η − η~0~)/(η~0~c) towards c → 0 constitutes the basis of traditional methods to determine intrinsic viscosities [η], where η is the viscosity of polymer solutions of concentration c and η~0~ is the viscosity of the pure solvent. With uncharged macromolecules this procedure works well; for polyelectrolytes it fails because of the pronounced non‐linearity of the above dependence at high dilution resulting from the increasing electrostatic interactions. This contribution presents a new method for the determination of [η]. It rests upon the application of the laws of phenomenological thermodynamics to the viscosity of polymer solutions and introduces a generalized intrinsic viscosity enabling a comparison of differently charged and uncharged polymers.

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