Polyanion‐polycation‐complex formation of charged microgels and latices with oppositely charged polyelectrolytes in solution

Abstract

Employing cationic, covalently crosslinked polyallylamine-based highly swollen microgels and anionic latices obtained by copolymerization of methacrylic acid and epoxypropyl methacrylate, the interaction of these polymer colloids with oppositely charged linear macroions is investigated by potentiometry, conductometry and turbidimetry. The microgels behave similar to linear macroions in symplex formation, if the components are reacted in the neutralized state, while in a "free acidfree base" titration only the easily accessible sites of the microgels are primarily involved in the interaction. With the more compact polymer latices a stable dispersion is formed, while with the microgels flocculation occurs. The results are discussed with regard to the influence of physical structure of the polymer colloids on stoichiometry and state of dispersion of the symplexes formed. Zur Bildung van Polyanion-Polykation-Komplexen aus geladenen Mikrogelen und Latices mit entgegengesetzt geladenen Polyelektrolyten in LosungUnter Verwendung kationischer covalent vernetzter hoch gequollener Mikrogele auf Polyallylaminbasis und anionischer Latices aus Methacrylsaure-Epoxypropylmethacrylat-Copolymeren wird die Wechselwirkung dieser Polymerkolloide mit entgegengesetzt geladenen Makroionen mittels Potentiometrie, Konduktometrie und Turbidimetrie untersucht. Die Mikrogele verhalten sich bei der Symplexbildung ahnlich wie geloste lineare Polyelektrolyte, wenn beide Titrationskomponenten in neutralisierter Form vorliegen, wahrend bei einer Umsetzung zwischen freier Polysaure und freier Polybase primar nur die leicht zuganglichen Ladungszentren der Mikrogele an der Umsetzung mitwirken. Bei den Latises bildet sich bei der Titration eine stabile "Symplex-Dispersion", wahrend im Falle der Mikrogele Flockung erfolgt. Die Ergebnisse werden hinsichtlich des Einflusses der Zuganglichkeit der Polymerkolloide auf Stochiometrie und Dispersitatszustand der gebildeten Symplexe diskutiert.

Multilayer Films Fabricated from Oppositely Charged Polyphenylene Dendrimers by Electrostatic Layer‐by‐Layer Assembly

“…This method was based on the stoichiometric reaction of a polyion with the oppositely charged polyion at a specific and constant ionic strength (<1 Â 10 À3 M) to form a complex, the so-called simplex complex. [12] The titration end point was determined by a particle charge detection apparatus of Mütek (Germany), the operation mode of which is based on the electrokinetic occurrence of a flow potential. [13] It consisted of a particle charge detector Mütek PCD03 pH standard equipped with an Ag/AgCl pH mini electrode and a Metrohm Titrino 702 SM automatic titrator.…”

Peripheral blood stem cell mobilization for hematopoietic support of radioimmunotherapy in patients with breast carcinoma

“…In order to characterize the charge density of the dendrimer units as a function of pH, the dendrimers were titrated with poly(ethylenesulfonic acid sodium salt) (PES‐Na) or poly(diallyldimethylammonium chloride) (PDADMAC) depending on the characteristic charges. This method was based on the stoichiometric reaction of a polyion with the oppositely charged polyion at a specific and constant ionic strength (<1 × 10 −3 M ) to form a complex, the so‐called simplex complex 12. The titration end point was determined by a particle charge detection apparatus of Mütek (Germany), the operation mode of which is based on the electrokinetic occurrence of a flow potential 13.…”

Zwitterionic Nanogels and Microgels: An Overview on Their Synthesis and Applications

“…[71] Unlike in polybetaines, the two types of charges can be present in stoichiometric nonequivalence, thereby making the overall charge weighted toward being either positive or negative (polyanionic or polycationic microgels). [72][73][74][75][76] Therefore, unlike polyampholytes, zwitterionic microgels exhibit some special characteristic features. Due to the prevalence of strong coulombic interactions along the polymer backbone, the zwitterionic microgels become superhydrophilic and as a result, they do not behave as typical polyelectrolytes and show great tolerance to extremely saline condition.…”