Jeanne CASETTA
defended her PhD
on 4 december 2023
“Développement de nouvelles membranes nano-structurées à base de fibres creuses
par modification de leur surface pour application au traitement de l’eau”
in front of the le jury composed of:
– M. Jean-Christophe REMIGY, Pr. des Universités – Université Paul Sabatier – Toulouse – Rapporteur
– Mme Elisabeth BLANQUET, Directrice de Recherches – CNRS – Grenoble INP · SIMAP – UGA – Rapporteur
– Mme Christelle WISNIEWSKI, Pr. des Universités – UMR QualiSud, Faculté des Sciences pharmaceutiques et biologiques -Université de Montpellier – Examinatrice
– M. Nikolaos KANELLOPOULOS, Directeur de Recherches – Demokritos NCSRD – Greece – Examinateur
– M. Philippe MIELE, Pr. des Universités – ENSCM – Université de Montpellier – Directeur de thèse
– Mme Céline POCHAT-BOHATIER, Maitre de Conférences – Polytech Montpellier – Université de Montpellier – Co-Directrice de thèse
– M. Mikhael BECHELANY, Directeur de Recherches – Institut Européen des Membranes – UMR563 – CNRS Montpellier – Invité
Abstract:
The aim of this thesis is to develop novel nano-structured hollow fiber polysulfone membranes by modifying their surface for water treatment applications. Two completely different approaches have been investigated: the first involves the “off-line” coating modification via atomic layer deposition (ALD) and the second involves the “on-line” addition of a nano-filler to the polymer solution during the synthesis of membranes by extrusion. In the first case, the ALD method was chosen for its excellent uniformity, reproducibility and homogeneity, and different oxides were studied by testing an increasing number of cycles. In the second, graphene oxide (GO), known for its unique properties, such as hydrophilicity and good mechanical properties provided by its many functional groups, was selected for the
preparation of mixed-matrix membranes. The deposition of the various oxides, TiO2, ZnO and Al2O3, was demonstrated by EDX and XPS. The morphologies and mechanical properties of the modified membranes were not altered, and their performances were significantly improved. For the 2nd approach, polysulfone fibers were prepared by extrusion by inserting 1wt.% GO into the polymer solution. The influence of this insertion on the nano-structuration of the membranes, particularly during NIPS, was studied. The modified membranes exhibit randomly distributed macrovoids, larger pores, increased hydrophilicity and a four-fold increase in permeability. Their anti-fouling performance on 4 different model contaminants often present in wastewater and the mechanisms involved are also explored.
Keywords: Membrane, ultrafiltration, hollow fiber, polysulfone, atomic layer deposition, spinning, non-solvent induced phase inversion, graphene oxide
