HYDROPHOBIC POLYELECTROLYTES IN BETTER POLAR SOLVENT. STRUCTURE AND CHAIN CONFORMATION AS SEEN BY SAXS AND SANS

Abstract : We demonstrate in this paper the influence of solvent quality on the structure of the semi-dilute solution of a hydrophobic polyelectrolyte, partially sulfonated Poly-Styrene Sulfonate. Two solvents are used: (i) one mixture of water and an organic solvent: THF, which is also slightly polar; (ii) DMSO, a polar organic solvent. In case (i), it is shown by SAXS study that the structure - namely the scattering from all chains, characterised by a maximum (“polyelectrolyte peak”), of the aqueous hydrophobic polyelectrolyte solutions (PSS) depends on the solvent quality through the added amount of organic solvent THF. This dependence is more pronounced when the sulfonation rate is low (more hydrophobic polyelectrolyte). It is proposed that when THF is added, the chain conformation evolves from the pearl necklace shape already reported in pure water, towards the conformation in pure water for fully sulfonated PSS, which is string-like as also reported previously. On the contrary, for a hydrophilic polyelectrolyte, AMAMPS, no evolution occurs with added THF in the aqueous solution. In case (ii), it is shown directly by SANS study that PSS can behave as a classical solvophilic polyelectrolyte when dissolved in an organic polar solvent such as DMSO: the structure (total scattering) as well as the form factor (single chain scattering measured by SANS using the Zero Average Contrast method) of the PSS chains is independent of the charge content in agreement with Manning condensation, and identical to the one of a fully charged PSS chain in pure water, which has a classical polyelectrolyte behaviour in the semi-dilute regime.
Complete list of metadatas

https://hal.archives-ouvertes.fr/hal-00446551
Contributor : François Boué <>
Submitted on : Wednesday, January 13, 2010 - 12:37:16 AM
Last modification on : Monday, February 10, 2020 - 6:12:13 PM
Long-term archiving on: Friday, June 18, 2010 - 12:46:26 AM

Files

Essafi_and_co_3d_revised_versi...
Files produced by the author(s)

Identifiers

Collections

Citation

Wafa Essafi, Marie Noelle Spiteri, Claudine Williams, François Boué. HYDROPHOBIC POLYELECTROLYTES IN BETTER POLAR SOLVENT. STRUCTURE AND CHAIN CONFORMATION AS SEEN BY SAXS AND SANS. International Journal of Biological Macromolecules, Elsevier, 2009, 42 ((24)), pp.9568-9580. ⟨10.1021/ma9003874⟩. ⟨hal-00446551⟩

Share

Metrics

Record views

387

Files downloads

397