Structure and mechanism formation of polyelectrolyte complex obtained from PSS/PAH system: effect of molar mixing ratio, base–acid conditions, and ionic strength
| Autor: | Amir Darío Maldonado-Arce, César Márquez-Beltrán, Gerardo Paredes-Quijada, M. Enciso-Aguilar, Heriberto Acuña-Campa, Luis Castañeda, Jean Francois Argillier |
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| Rok vydání: | 2012 |
| Předmět: |
chemistry.chemical_classification
Aqueous solution Polymers and Plastics Chemistry Inorganic chemistry Polyelectrolyte Colloid and Surface Chemistry Dynamic light scattering Ionic strength Materials Chemistry Zeta potential Physical and Theoretical Chemistry Counterion Sodium Polystyrene Sulfonate Polyallylamine hydrochloride |
| Zdroj: | Colloid and Polymer Science. 291:683-690 |
| ISSN: | 1435-1536 0303-402X |
| DOI: | 10.1007/s00396-012-2775-y |
| Popis: | Colloidal dispersions of polyelectrolyte complexes were prepared in aqueous solutions. We have used mixtures containing the strongly charged anionic polyelectrolyte sodium polystyrene sulfonate (PSS) and the weak cationic polyelectrolyte polyallylamine hydrochloride (PAH). Both polymers have the same molecular weight. The complexes were obtained by adding drop by drop a solution of the anionic polyelectrolyte to excess cationic polyelectrolyte. In these conditions, sodium polystyrene sulfonate and polyallylamine hydrochloride self-assembled in nanometer-range complexes; the self-assembly is driven by electrostatic interactions, as well as by entropy changes due to counterion release. The electrostatic interactions were controlled in several ways: by changing the C PSS/C PAH concentration ratio, by modifying the pH (and thus the protonation degree of polyallylamine hydrochloride), and by adding sodium chloride (screened interactions). Dynamic light scattering experiments demonstrated that the hydrodynamics radius of the polyelectrolyte complex increases, changing from soluble to insoluble complex formation, when some physicochemical parameters are increased: the concentration ratio between polyelectrolytes, the sodium chloride concentration, and pH. Zeta potential measurements, as a function of the C PSS/C PAH concentration ratio, as well as of pH and ionic strength, allow us to state that the resulting particles have a structure constituted by a neutral core surrounded by a positively charged shell. The polyelectrolyte complexes have globular shapes, as observed by electron microscopy. |
| Databáze: | OpenAIRE |
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