The interaction between two oppositely charged polyelectrolytes
โ Scribed by A. Polderman
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1975
- Tongue
- English
- Weight
- 715 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0006-3525
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โฆ Synopsis
Abstract
Mixtures of a weak polybase (polyethylenimine) and a weak polyacid acrylamideโacrylic acid copolymer in aqueous solutions at several ionic strengths and polymer concentrations are studied potentiometrically. When the concentrations of the polyethylenimine and acrylamideโacrylic acid copolymer charges are not too different, phase separation into two liquid phases (โcomplex coacervationโ) is observed. In the pH region where no phase separation occurs, potentiometric titrations are performed on mixtures of both polymers. From the titrations of polyethylenimine solutions, acrylamideโacrylic acid copolymer solutions, and the mixtures, the free energy of interaction has been evaluated according to the theory of Litan. The dependence of the free energy of interaction on pH, polymer concentrations, and ionic strength is explained quantitatively with a model of cooperative electrostatic physical association.
๐ SIMILAR VOLUMES
Adsorption of polyelectrolytes to surfaces of opposite charge typically leads to charge neutralization and subsequent charge reversal. As can be shown by direct force measurements and stability studies, the interaction forces are dominated by repulsive forces originating from diffuse layer overlap a
Polyelectrolyte chains confined by oppositely charged macroions can significantly modify the interactions between them. This polyelectrolyte mediated interaction depends on various parameters characterizing the polyelectrolyte as well as the surface of the macroion and can be either repulsive or att