La thèse se déroulera le lundi 26 janvier 2015 à 10h, dans l’Amphi1, MRV : Campus UPS.
Previous works have shown that the transfer of neutral solutes through membranes is influenced by the presence of ions in solution.
The aim of this Thesis is to use a combined quantum/molecular computational approach and experimental methodologies to better understand how ions can affect the solute flux. In the first part of the work, some properties of ions in solution are computed and are compared with sugar fluxes through membrane for nanofiltration and electrodialysis in order to understand what is the key-property.
In the following, building blocks of a Ion-Exchange Membrane (CMX,
Neosepta) equilibrated by the different counter-ion and the hydrated glucose were first accurately studied at high level of quantum theory, before being merged in macromolecular models.
These models were examined by Quantum Mechanics/Molecular Mechanics in order to investigate the sugar solubility in the polymer matrix or diffusion related interactions as the polymer chain-chain. The computed values of the glucose solubility inside the polymer were found to be almost independent of the cation. On the contrary, the interaction energies per trapped water molecule or hydrogen bonding wire connecting the polymer fragments was found to vary with the cation. A correlation was also pointed out with the experimental values of the sugar flux In the last part, computational methods and experimental are used to characterize the physical properties of the membrane and possible influence of the counter-ion on cation exchange membrane. For this reason, contact angle, differential scanning calorimetry and Infra-Red spectra are measured.
Furthermore, for a close comparison, the vibrational properties are also computed in the frame of Density Functional Theory.
Then this work shows, by both computational and experimental methods, that the cohesion energy between the membrane polymer fragments fixes the dependence of the sugar flux with respect to the counter-ion.
Composition du Jury :
- Hélène ROUX-de BALMANN : Directrice de Recherches, LGC CNRS, Toulouse
- Giorgio DE LUCA : Directeur de Thèse , Chercheur, ITM - CNR, Rende
- Harmen ZWIJNENBERG : Directeur de Thèse, Chercheur, MST - EMI - UT, Enschede
- Giacomo SAIELLI : Directeur de Thèse , Professeur, Unipd, Padova
- Anthony SZYMCZYK : Rapporteur, Professeur, ISCR, Rennes
- Laurent MARON : Rapporteur, Professeur, LPCNO UPS, Toulouse
- Raffaele MOLINARI : Examinateur, Professeur, Diatic - Unical, Rende
- Stéphane DESOBRY : Examinateur, Professeur, LIBio - ENSAIA, Vandoeuvre
- Sylvain GALIER : Examinateur, Maitre de Conférences, LGC-UPS, Toulouse
- Kitty NIJMEIJER : Invité, Professeur, MST - UT, Enschede (Invité)
- Electrolytes, Membranes, sugar transfer, Quantum Mechanics/Molecular Mechanics, Differential Scanning Calorimetry, Contact Angle, InfraRed Spectroscopy