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SAXS from Four‐Arm Polyelectrolyte Stars in Semi‐Dilute Solutions
Author(s) -
Moinard Delphine,
Taton Daniel,
Gnanou Yves,
Rochas Cyrille,
Borsali Redouane
Publication year - 2003
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200290061
Subject(s) - polyelectrolyte , counterion , electrolyte , acrylate , small angle x ray scattering , scattering , chemistry , polymer chemistry , materials science , ion , polymer , physics , copolymer , organic chemistry , optics , electrode
We have performed small‐angle X‐ray scattering experiments on semi‐dilute solutions of highly charged star polyelectrolytes. Poly(sodium acrylate) (PANa) and poly(cesium acrylate) (PACs) stars with four arms were successfully synthesized by a combination of atom transfer radical polymerization and chemical modifications. Over a wide range of polyelectrolyte concentration C p , these two systems as well as their equivalent linear polyelectrolytes were investigated at different ionic strengths. Scattering experiments show the existence of a scattering peak denoted as q max , which disappears with the addition of a simple electrolyte, evidencing the electrostatic character of the interactions. We have also studied the effect of the charge parameter and the nature of the counterion (Na and Cs) on the scattering properties of these star polyelectrolytes. In the case of PACs, q max scales with the polyelectrolyte concentration as C p 1/2 over the whole range of studied concentrations, whereas it scales as C p 1/2 (for C p < 45 mg · ml −1 ) and C p 1/4 (for C p > 45 mg · ml −1 ) in the case of PANa.Variation of q max as a function of polyelectrolyte concentration C p for PA1Cs (○) and PA2Cs (•) stars (error bars are indicated).