ED Sciences Chimiques
Bio-inspired catalysis in aqueous droplets: towards a new chemistry of life
by Kevin PEYRAUD-VICRÉ (Acides nucléiques : Régulations Naturelles et Artificielles)
The defense will take place at 14h30 - Amphithéâtre CRPP Centre de Recherche Paul Pascal (CRPP). 115 Avenue du Dr Albert Schweitzer, 33600 PESSAC
in front of the jury composed of
- Valérie DESVERGNES - Directrice de recherche - Université de Bordeaux - Directeur de these
- Emmanuelle MARIE - Directrice de recherche - ENS Paris - Rapporteur
- Estelle MéTAY - Directrice de recherche - Université Claude Bernard, Lyon 1 - Rapporteur
- Nicolas MARTIN - Chargé de recherche - Université de Bordeaux - CoDirecteur de these
- Jean-François BRIèRE - Directeur de recherche - Université de Rouen Normandie - Examinateur
- Olivier MONDAIN-MONVAL - Professeur des universités - Université de Bordeaux - Examinateur
Coacervates are membrane-free aqueous microdroplets formed through liquid–liquid phase separation. They differ from micelles and vesicles in both composition and size. Known for their ability to concentrate enzymes and organic molecules, coacervates can be considered as microreactors or reaction microcompartments. Still largely underexplored in the field of organic chemistry, coacervates offer a unique and original reaction medium for the development of chemical transformations in aqueous solution. This thesis highlights their potential for bio-inspired reactions catalyzed by N-heterocyclic carbenes (NHCs), which are particularly sensitive to the presence of water. We demonstrate that a model Stetter reaction, involving the formation of C–C bonds, can be efficiently carried out in synthetic model coacervates. This approach then led to the design of novel bio-inspired coacervates based on azolium salts, analogous to the natural cofactor thiamine diphosphate, and anions such as ATP, combining compartmentalization with catalytic activation. Other NHC-catalyzed reactions, such as oxidative esterification, were also developed. Altogether, this work presents an integrated and innovative approach to catalysis in aqueous solution, based on the use of self-organized compartmentalized systems.
PREPARATION OF AMPHIPHILIC CELLULOSE NANOCRYSTALS BY SURFACE INITIATED ATOM TRANSFER RADICAL POLYMERIZATION (SI-ATRP) FROM PARTICLES IMMOBILIZED AT THE INTERFACE OF PICKERING EMULSIONS
by Yelin HOU (Laboratoire de Chimie des Polymères Organiques)
The defense will take place at 9h30 - En cours de validation Ecole Nationale Supérieure de Matériaux, d'Agroalimentaire et de Chimie, ENSMAC (ex ENSCBP), 16 Avenue Pey-Berland, 33607 Pessac Cedex France
in front of the jury composed of
- Gilles SEBE - Maître de conférences - Université de Bordeaux - Directeur de these
- Ana VILLARÈS - Directrice de recherche - INRAE Unité BIA, Biopolymères Interactions et Assemblages - Rapporteur
- Bruno JEAN - Directeur de recherche - CERMAV – CNRS, Université Grenoble Alpes - Rapporteur
- Henri CRAMAIL - Professeur - Université de Bordeaux - Examinateur
- Zhen ZHANG - Associate Professor - South China Normal University - Examinateur
In this work, we investigated an original method to prepare amphiphilic cellulose nanocrystals (CNCs) by interfacial surface-initiated atom transfer radical polymerization (SI-ATRP) of Pickering emulsions stabilized by CNCs bearing brominated ATRP initiating. In the first part of the thesis, a new approach involving polydopamine (PDA) as an intermediate layer was developed to introduce reactive bromoisobutyryl sites at the CNCs surface, and compared with the common esterification method with 2-bromoisobutyryl bromide. In the second part of the thesis, the brominated CNCs prepared with the two previous methods were used to stabilize oil-in-water (O/W) and/or water-in-oil (W/O) emulsions containing a hydrophilic monomer (N-isopropylacrylamide) in the water phase, and a hydrophobic one (Styrene) in the oil phase. After biphasic SI-ATRP polymerization from the brominated particles immobilized at the oil-water interface, CNCs decorated with both polystyrene and poly(N-isopropylacrylamide) chains were recovered and characterized in terms of chemical structure, morphology, amphiphilicity and emulsifying properties. The results obtained with the different emulsion systems (O/W or W/O) and different bromination methods were particularly compared.
ED Sciences Physiques et de l'Ingénieur
Development of integrated photonic architectures in hybrid materials based on femtosecond laser processing
by Raphaël HAZEM (Centre Lasers Intenses et Applications)
The defense will take place at 10h00 - Amphithéâtre de l'ICMCB 87 Avenue du Dr Albert Schweitzer, ICMCB, 33600 Pessac
in front of the jury composed of
- Lionel CANIONI - Professeur des universités - Université de Bordeaux-ICMCB - Directeur de these
- Matthieu BELLEC - Chargé de recherche - Institut de Physique de Nice (INPHYNI) UMR 7010 - Rapporteur
- Yves QUIQUEMPOIS - Professeur des universités - Laboratoire de Physique des Lasers, Atomes et Molécules (PhLAM) UMR 8523 - Rapporteur
- Alexis CASNER - Directeur de recherche - CEA DAM Île-de-France - Examinateur
- Yannick PETIT - Maître de conférences - Université de Bordeaux-ICMCB - CoDirecteur de these
- Cyril AYMONIER - Directeur de recherche - ICMCB-CNRS - Examinateur
Laser-based additive manufacturing has found widespread applications in fields such as aerospace, medicine, and automotive engineering, enabling the fabrication of three-dimensional objects from digital models. Over the past decade, it has also emerged as a promising technique for the fabrication of optical components, particularly through multiphoton polymerization of photosensitive polymer resins for micro-optics. Advances in resin formulations specifically tailored to nonlinear processes have significantly improved resolution, paving the way for the fabrication of the first photonic devices. In this PhD work, we investigate hybrid (organic–inorganic) polymer resins that exhibit glass-like properties and improved long-term stability for photonic applications. We explore the physical mechanisms of multiphoton photopolymerization to optimize the optical properties of printed structures. We developed a 3D+1 printing strategy with these hybrid resins to enhance their refractive index modulation capabilities. As a proof of concept, we fabricated and characterized low-loss integrated photonic components, demonstrating the potential of this approach for future photonic circuit integration.