Premium
Hydrodynamic Size and Electrophoretic Mobility of Poly(styrene sulfonate) versus Molecular Weight
Author(s) -
Böhme Ute,
Scheler Ulrich
Publication year - 2007
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.200700386
Subject(s) - counterion , electrophoresis , counterion condensation , macromolecule , chemistry , sulfonate , polymer chemistry , styrene , shielding effect , condensation , diffusion , charge (physics) , copolymer , dissociation (chemistry) , chemical physics , analytical chemistry (journal) , polymer , organic chemistry , chromatography , thermodynamics , ion , physics , sodium , biochemistry , layer (electronics) , quantum mechanics
The effective charge of a macromolecule in solution is significantly smaller than the nominal charge, derived form the number of charged groups and the degree of dissociation. It is reduced by counterion condensation, shielding a considerable fraction of the macromolecules charge. As an example the influence of the molecular weight on hydrodynamic size and electrophoretic mobility of poly(styrene sulfonate) has been investigated. While from diffusion the hydrodynamic size is inferred, in a combination with electrophoresis NMR the effective charge is calculated. At low molecular weight the effective charge is equal to the nominal charge, in an intermediate range the effective charge is that predicted from counterion condensation theory, while at higher molecular weights it becomes considerably smaller.