Skip to Main content Skip to Navigation
Theses

Adsorption de polyélectrolytes par une surface liquide chargée

Abstract : We have studied the adsorption of weak polyelectrolytes by a soft surface (Langmuir film) of opposite charge, as a function of the surface charge density Sigma and of the polymers charge fraction f. Different regimes have been evidenced (ellipsometry, IR spectroscopy). For small values of Sigma, the adsorbed polyelectrolytes neutralize the surface : Gamma=Sigma/f (number of adsorbed monomers per unit surface). For high values of Sigma, it costs less to continue the surface neutralization with counter-ions : Gamma~SigmaION/f with SigmaION~f^0.35. For weak f (~0.12), Gamma is significant and the mixed film properties (amphiphile+polyelectrolytes) are dominated by polymers. The surface pressure due to the polymers is proportional to Sigma^2. A regime change was observed in elasticity and overcompensation of the surface charge. It corresponds, according to recent theories, to a change in the polymer conformation, from flat to 3D. For higher f, the film properties are governed by the amphiphiles.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00009397
Contributor : Sylvie Hénon <>
Submitted on : Monday, June 6, 2005 - 6:20:14 PM
Last modification on : Wednesday, December 9, 2020 - 3:06:04 PM
Long-term archiving on: : Friday, April 2, 2010 - 9:53:29 PM

Identifiers

  • HAL Id : tel-00009397, version 1

Citation

Laurianne Vagharchakian. Adsorption de polyélectrolytes par une surface liquide chargée. Analyse de données, Statistiques et Probabilités [physics.data-an]. Université Pierre et Marie Curie - Paris VI, 2003. Français. ⟨tel-00009397⟩

Share

Metrics

Record views

314

Files downloads

1080