Open AccessPolyelectrolyte Complex Coacervation across a Broad Range of Charge Densities
Author(s) -
Angelika E. Neitzel,
Yan Fang,
Boyuan Yu,
Artem M. Rumyantsev,
Juan J. de Pablo,
Matthew Tirrell
Publication year - 2021
Publication title -
macromolecules
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.994
H-Index - 313
eISSN - 1520-5835
pISSN - 0024-9297
DOI - 10.1021/acs.macromol.1c00703
Subject(s) - coacervate , polyelectrolyte , comonomer , phase (matter) , ethylene oxide , chemistry , scaling , charge (physics) , thermogravimetric analysis , polymer , polymer chemistry , chemical physics , analytical chemistry (journal) , thermodynamics , monomer , chromatography , physics , organic chemistry , copolymer , geometry , mathematics , quantum mechanics
Polyelectrolyte complex coacervates of homologous (co)polyelectrolytes with a near-ideally random distribution of a charged and neutral ethylene oxide comonomer were synthesized. The unique platform provided by these building blocks enabled an investigation of the phase behavior across charge fractions 0.10 ≤ f ≤ 1.0. Experimental phase diagrams for f = 0.30-1.0 were obtained from thermogravimetric analysis of complex and supernatant phases and contrasted with molecular dynamics simulations and theoretical scaling laws. At intermediate to high f , a dependence of polymer weight fraction in the salt-free coacervate phase ( w P,c ) of w P,c ∼ f 0.37±0.01 was extracted; this trend was in good agreement with accompanying simulation predictions. Below f = 0.50, w P,c was found to decrease more dramatically, qualitatively in line with theory and simulations predicting an exponent of 2/3 at f ≤ 0.25. Preferential salt partitioning to either coacervate or supernatant was found to be dictated by the chemistry of the constituent (co)polyelectrolytes.