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Effective size and fractal dimension of polyelectrolytes determined by diffusion NMR
Author(s) -
Böhme Ute,
Scheler Ulrich
Publication year - 2002
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/1521-3900(200208)184:1<349::aid-masy349>3.0.co;2-1
Subject(s) - polyelectrolyte , ionic strength , hydrodynamic radius , diffusion , fractal dimension , chemical physics , ionic bonding , macromolecule , pulsed field gradient , chemistry , molecule , radius , solubility , fractal , thermodynamics , materials science , aqueous solution , polymer , organic chemistry , physics , ion , mathematical analysis , biochemistry , mathematics , computer security , computer science , micelle
Polyelectrolytes are macromolecules containing dissociable or charged groups on the main chain or in side groups. These charges are the basis of the water solubility of polyelectrolytes. The solution properties namely the conformation is determined by an interplay of thermodynamic and electric interactions. The electrostatic interaction is influenced by the ionic strength of the solution. As a measure of the effective size of the macromolecules the hydrodynamic radius is determined from the self‐diffusion coefficient measured via pulsed‐ field gradient nuclear magnetic resonance. From variation of the hydrodynamic radius with molecular weight for each ionic strength, the fractal dimension has been determined for the example of poly(styrenesulfonate). With increasing ionic strength the fractal dimension, which describes the use of space for the fictitious growth of the molecule when increasing the molecular weight, increases. This implies a denser packing of the molecules in higher ionic strength.