Skip to Main content Skip to Navigation
Journal articles

On the crossroads of current polyelectrolyte theory and counterion-specific effects

Abstract : Aqueous solutions of polyelectrolytes are studied here by means of neutron scattering, with emphasis on backbone hydrophobicity and counter ion specific effects. Ionene polyelectrolytes with varying chain charge density and different counter ions are considered. Their neutron scattering data feature a number of aspects and trends that clearly deviate from the predictions of the existing theory. Ionenes challenge the current hydrophilic-hydrophobic classification of water-soluble polyelectrolytes. The hydrophobic character of their hydrocarbon backbone emerges only for very low chain charge densities (at 15% of charged monomers), which is significantly lower than for other polyelectrolytes with a more complex structure. Universality in the counter ion specific effect seen in ionene solutions with Br(-) or F(-) counterions is established. The polyelectrolyte peak in the scattering spectra of Br-ionenes disappears beyond a specific charge concentration, which is identical across all ionene chain charge densities. In addition, scattering spectra of Br-ionenes and F-ionenes feature contrasting temperature trends, which are accentuated with decreasing chain charge density. Our interpretation of the F-Br effect, based on the different hydration properties of the counter ions, is supported by additional NMR measurements on ionenes with mixed counter ion clouds. Overall, the study of ionene polyelectrolytes points clearly to the need for combining the scaling concepts with those of ion specificity, to obtain a theoretical framework encompassing the wealth of phenomena occurring in polyelectrolyte solutions.
Document type :
Journal articles
Complete list of metadata

Cited literature [42 references]  Display  Hide  Download

https://hal.sorbonne-universite.fr/hal-01140391
Contributor : Administrateur Hal-Upmc <>
Submitted on : Wednesday, April 8, 2015 - 2:54:23 PM
Last modification on : Saturday, December 12, 2020 - 3:58:46 AM
Long-term archiving on: : Tuesday, April 18, 2017 - 2:50:20 PM

File

Malikova_2015_On_the_crossroad...
Publication funded by an institution

Identifiers

Citation

Natalie Malikova, Anne-Laure Rollet, Sašo Čebašek, Matija Tomšič, Vojko Vlachy. On the crossroads of current polyelectrolyte theory and counterion-specific effects. Physical Chemistry Chemical Physics, Royal Society of Chemistry, 2015, 17 (8), pp.5650-5658. ⟨10.1039/C4CP05469E⟩. ⟨hal-01140391⟩

Share

Metrics

Record views

209

Files downloads

537