TY - JOUR
T1 - Structure and mechanism formation of polyelectrolyte complex obtained from PSS/PAH system
T2 - Effect of molar mixing ratio, base-acid conditions, and ionic strength
AU - Márquez-Beltrán, César
AU - Castañeda, L.
AU - Enciso-Aguilar, M.
AU - Paredes-Quijada, Gerardo
AU - Acuña-Campa, Heriberto
AU - Maldonado-Arce, Amir
AU - Argillier, Jean François
PY - 2013/3
Y1 - 2013/3
N2 - 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.
AB - 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.
KW - Colloidal behavior
KW - Interfaces
KW - Surfaces
UR - http://www.scopus.com/inward/record.url?scp=84878353673&partnerID=8YFLogxK
U2 - 10.1007/s00396-012-2775-y
DO - 10.1007/s00396-012-2775-y
M3 - Artículo
SN - 0303-402X
VL - 291
SP - 683
EP - 690
JO - Colloid and Polymer Science
JF - Colloid and Polymer Science
IS - 3
ER -