title: Structure, thermodynamic and kinetic signatures of a synthetic polyelectrolyte coacervating system.
abstract: While many studies on coacervation have targeted biomacromolecules, we review in this article the key structure, thermodynamic and kinetic features of a fully synthetic coacervating system based on polyacrylic acid (PAA) and poly(diallyldimethylammonium chloride) (PDADMAC) oppositely charged polyelectrolytes at pH10, where PAA chains are fully deprotonated. Among the main points of interest, we can highlight (i) the presence of polyelectrolyte complex (PEC) nanoparticles that, unexpectedly, coexist with a certain amount of coacervate droplets in a large range of compositions, even far from stoichiometry; (ii) the fact that these PEC nanoparticles are likely precursors of the coacervation occurring at stoichiometry; (iii) the formation of soluble PECs only in a certain range of physicochemical conditions; (iv) the equilibrium properties of the system; (v) and last but not least a distinctive kinetic signature at stoichiometry evidenced by a peak in light scattering at very short times (~100ms). Some of these results can be rationalized on the basis of weak interaction unfolding between oppositely charged PAA and PDADMAC chains as revealed by microcalorimetry measurements.
authors.affiliation: CNRS, Centre de Recherche Paul Pascal (CRPP), UPR 8641, F-33600 Pessac, France; Université de Bordeaux, Centre de Recherche Paul Pascal, F-33600 Pessac, France; Université de Bordeaux, Laboratoire de Chimie des Polymères Organiques, UMR 5629, Bordeaux INP/ENSCBP, 16 avenue Pey-Berland, F-33607 Pessac, France; CNRS, Laboratoire de Chimie des Polymères Organiques, UMR 5629, F-33607 Pessac, France.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Liu
authors.affiliation: CNRS, Centre de Recherche Paul Pascal (CRPP), UPR 8641, F-33600 Pessac, France; Université de Bordeaux, Centre de Recherche Paul Pascal, F-33600 Pessac, France. Electronic address: chapel@crpp-bordeaux.cnrs.fr.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Chapel
authors.affiliation: Université de Bordeaux, Laboratoire de Chimie des Polymères Organiques, UMR 5629, Bordeaux INP/ENSCBP, 16 avenue Pey-Berland, F-33607 Pessac, France; CNRS, Laboratoire de Chimie des Polymères Organiques, UMR 5629, F-33607 Pessac, France. Electronic address: schatz@enscbp.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Schatz
keywords: Coacervation; Poly(acrylic acid); Poly(diallyldimethylammonium) chloride; Polyelectrolyte complexation