Jeudi 3 novembre 2016 : Thèse de Lucia Benavente
La thèse se déroulera le Jeudi 3 novembre 2016 en Amphi II, MRV (Maison de la Recherche et de la Valorisation) sur le Campus UPS-Rangueil) à 10h
Intitulé de la Thèse :
"Low fouling membranes for water and biotech applications"
João CRESPO, Professeur, Universidade Nova de Lisboa, Portugal (Rapporteur)
Murielle RABILLER-BAUDRY, Professeur, Université de Rennes, France (Rapporteur)
Anne BREHANT, Ingénieur, Suez Environnement, France
Yung CHANG, Professeur, Chung Yuan Christian University, Taïwan
Patrice BACCHIN, Professeur, Université de Toulouse (Directeur de thèse)
Pierre AIMAR, Dir. de Recherche CNRS, Université de Toulouse (Directeur de thèse)
Water scarcity has become one of the key issues to solve, and efficient water treatment is paramount to treat water sources. In recent decades membrane technology has become one of the promising solutions for water treatment. Nevertheless, membranes are prone to fouling phenomena - the deposition, adsorption, and absorption of particles in the membrane structure -, which hinders their life-span and productivity, and raise operative costs. One approach to minimize this issue is to modify the already mechanically and chemically stable hydrophobic membranes with amphiphilic materials.
The main aim of this work is to characterise the anti-fouling properties of PVDF (Polyvinylidene fluoride) membranes modified with different types of PS-PEGMA (Polystyrene – Poly(ethylene glycol) methacrylate) copolymers, firstly by using classical techniques, and then, by developing and/or adapting new ones : microfluidic devices coupled with fluorescence microscopy, and the use of Fourier Transform Infrared microspectroscopy (FTIR mapping).
FTIR mapping allowed the local detection of the coating layer and showed its heterogeneous distribution on the surface of the membrane. These maps, that represent the importance of the coating on the membrane, were correlated with the deposit of proteins on the surface. Microfluidic systems were also developed to characterise the adsorption of fluorescent proteins on the membrane under a fluorescent microscope in the presence of a flow. This study allowed the in-situ and dynamic follow-up of the adsorption – during filtration cycles – and of the desorption – during rinsing cycles – of the proteins on the membrane. These local measurements were compared against permeability measurements during the filtration/rinsing cycles evidencing the anti-fouling role of the copolymers used for the modification of the membranes, particularly for the triblock and random copolymers.
fouling, water treatment, adsorption, membrane modification, PVDF, PS-PEGMA