No description available.

The majority of state-of-the-art polymeric membranes for industrial or medical applications are fabricated by phase inversion. Complexation induced phase separation (CIPS)—a surprising variation of this well-known process—allows direct fabrication of hybrid membranes in existing facilities. In the CIPS process, a first step forms the thin metal-rich selective layer of the membrane, and a succeeding step the porous support. Precipitation of the selective layer takes place in the same solvent used to dissolve the polymer and is induced by a small concentration of metal ions. These ions form metal-coordination-based crosslinks leading to the formation of a solid skin floating on top of the liquid polymer film. A subsequent precipitation in a nonsolvent bath leads to the formation of the porous support structure. Forming the dense layer and porous support by different mechanisms while maintaining the simplicity of a phase inversion process, results in unprecedented control over the final structure of the membrane. The thickness and morphology of the dense layer as well as the porosity of the support can be controlled over a wide range by manipulating simple process parameters. CIPS facilitates control over (i) the thickness of the dense layer throughout several orders of magnitude—from less than 15 nm to more than 6 μm, (ii) the type and amount of metal ions loaded in the dense layer, (iii) the morphology of the membrane surface, and (iv) the porosity and structure of the support. The nature of the CIPS process facilitates a precise loading of a high concentration of metal ions that are located in only the top layer of the membrane. Moreover, these metal ions can be converted—during the membrane fabrication process—to nanoparticles or crystals. This simple method opens up fascinating possibilities for the fabrication of metal-rich polymeric membranes with a new set of properties. This dissertation describes the process in depth and explores promising applications: (i) catalytic membranes containing palladium nanoparticles (PdNPs), (ii) antibiofouling tight-UF membranes containing silver chloride (AgCl) crystals, and (iii) palladiumrich PBI hollow fibers for H2 recovery.

Les copolymères à blocs amphiphiles peuvent s’auto-assembler sous forme de vésicules,appelées polymersomes. Ces vésicules ont été développées et étudiées depuis de nombreusesannées notamment pour l’encapsulation et la délivrance contrôlée de médicaments. Depuisquelques temps, elles connaissent des applications dans le domaine du biomimétisme cellulaire.Plus robustes que leurs analogues lipidiques (liposomes), les avantages à utiliser lespolymersomes comme mimes synthétiques de cellules biologiques ne sont plus à démontrer.Ainsi, des structures compartimentées à base de polymères ont été développés comme mimesstructurels de cellules. Ces systèmes ont été utilisés comme bioréacteurs, avec la réalisation deréactions chimiques ou enzymatiques en cascade en milieu confiné. Toutefois, l’un desobstacles qu’il reste à franchir est de trouver des moyens simples et efficaces pour déclencherla réaction au sein de ces systèmes. C’est dans ce contexte que s’inscrivent les travaux de cettethèse. Une membrane synthétique asymétrique à base de lipide et polymère a été développée etla méthode d’émulsion-centrifugation a été utilisée pour produire des systèmes compartimentésbiomimétiques. De plus, deux approches différentes ont été suivies pour provoquer la libérationcontrôlée d’espèces encapsulées, l’une utilisant la température et l’autre la lumière. Enfin, desétudes de co-encapsulation de cellules synthétiques (polymersomes) et biologiques au sein demilieux 3D ont été réalisées dans le but d’évaluer leur compatibilité et la possibilité de les cocultiver. / Amphiphilic block copolymers can self-assemble into vesicles, also called polymersomes.These vesicles have been developed and studied for many years especially in the field of drugloading and controlled release. More recently, their use as cell mimics have attracted a lot ofattention, mainly because polymersomes exhibit many advantages in contrast to their lipidicanalogues (liposomes). In such, compartmentalized polymer systems have especially beendeveloped as structural mimics of cells. These systems have found applications as bioreactorsthat can confine cascade chemical or enzymatic reactions. However, a major goal that stillremains to achieve is to find ways to trigger the beginning of these chemical reactions insidethe compartmentalized structures. The work carried out during this PhD thesis was actually totackle this challenge. A synthetic asymmetric lipid – polymer membrane, that mimics themembrane of biological cells was developed and the emulsion-centrifugation protocol wasfollowed to prepare biomimetic compartmentalized structures. In addition, two different waysto control the independent release of multiple species from individual compartments weredeveloped, based on temperature or light activation. Lastly, co-encapsulation of synthetic cells(polymersomes) and biological cells were performed in 3D media with the aim to study theircompatibility for co-culture experiments.

No description available.