This title appears in the Scientific Report :
2007
Please use the identifier:
http://dx.doi.org/10.1063/1.2787008 in citations.
Please use the identifier: http://hdl.handle.net/2128/19084 in citations.
Probing the extent of the Sr2+ ion condensation to anionic polyacrylate coils: A quantitative anomalous small-angle x-ray scattering study
Probing the extent of the Sr2+ ion condensation to anionic polyacrylate coils: A quantitative anomalous small-angle x-ray scattering study
The shrinking process of anionic sodium polyacrylate (NaPA) chains in aqueous solution induced by Sr2+ counterions was analyzed by anomalous small-angle x-ray scattering. Scattering experiments were performed close to the precipitation threshold of strontium polyacrylate. The pure-resonant scatterin...
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Personal Name(s): | Goerigk, G. |
---|---|
Huber, K. / Schweins, R. | |
Contributing Institute: |
JCNS; JCNS Neutronenstreuung; IFF-5 Streumethoden; IFF-4 |
Published in: | The @journal of chemical physics, 127 (2007) S. 154908-1 - 154908-8 |
Imprint: |
Melville, NY
American Institute of Physics
2007
|
Physical Description: |
154908-1 - 154908-8 |
PubMed ID: |
17949215 |
DOI: |
10.1063/1.2787008 |
Document Type: |
Journal Article |
Research Program: |
Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) Kondensierte Materie |
Series Title: |
Journal of Chemical Physics
127 |
Subject (ZB): | |
Link: |
Get full text OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/19084 in citations.
The shrinking process of anionic sodium polyacrylate (NaPA) chains in aqueous solution induced by Sr2+ counterions was analyzed by anomalous small-angle x-ray scattering. Scattering experiments were performed close to the precipitation threshold of strontium polyacrylate. The pure-resonant scattering contribution, which is related to the structural distribution of the Sr2+ counterions, was used to analyze the extent of Sr2+ condensation onto the polyacrylate coils. A series of four samples with different ratios [Sr2+][NaPA] (between 0.451 and 0.464) has been investigated. From the quantitative analysis of the resonant invariant, the amount of Sr cations localized in the collapsed phase was calculated with concentrations v between 0.94x10(17) and 2.01x10(17) cm(-3) corresponding to an amount of Sr cations in the collapsed phase between 9% and 23% of the total Sr2+ cations in solution. If compared to the concentration of polyacrylate expressed in moles of monomers [NaPA], a degree of site binding of r=[Sr2+][NaPA] between 0.05 and 0.11 was estimated. These values clearly differ from r=0.25, which was established from former light scattering experiments, indicating that the counterion condensation starts before the phase border is reached and increases rather sharply at the border. |