Bienvenue au Département de physique !
Comment produire de l’énergie sans épuiser la planète ? Qu’est-ce que l’exploration de l’espace peut encore nous apprendre ? Comment soigner plus efficacement par protonthérapie ? L’intelligence artificielle, amie ou ennemie ? Et le chat de Schrödinger, finalement, comment va-t-il ?
Vous vous posez ce type de questions et vous aimeriez pouvoir y répondre. Vous aimeriez comprendre, connaître, résoudre, expérimenter, tester, coder, appliquer. Vous aimeriez vous engager pour préserver la planète, pour la santé, pour la société. Vous aimeriez relever le défi de la recherche en entreprise, ou vous préférez mettre vos compétences au service de la connaissance plus fondamentale. En rejoignant le Département de physique de l’Université de Namur, vous serez rassasié et nous vous accueillons avec enthousiasme.
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Événements
UNamur Raman Day
Une journée interactive organisée à l'Université de Namur, dédiée à la découverte du nouveau microscope Raman et réunissant chercheurs et professionnels de l'industrie.
L'Université de Namur (plateforme LOS) et ST Instruments ont le plaisir de vous inviter à l'événement consacré à la découverte du nouveau microscope Raman et à ses applications, qui réunira des chercheurs et des professionnels du secteur.
Spectroscopie Raman
Permettant une analyse chimique rapide et non destructive des solides, des films minces, des poudres et des liquides, cette technologie de pointe peut être appliquée à une multitude de secteurs : énergie, environnement, polymères, sciences de la vie, industrie pharmaceutique, nanomatériaux, semi-conducteurs, agroalimentaire, peintures, criminalistique, géologie ou archéométrie.
Optimisez vos recherches, vos analyses et dynamisez vos partenariats industriels
Tout au long de la journée, vous aurez l’occasion d’assister à des conférences d’experts sur la spectroscopie Raman, ainsi que de participer à des ateliers pratiques et à des démonstrations technologiques s’appuyant sur des cas d’application concrets. Au cours de ces sessions, vous pourrez échanger avec des spécialistes de ST Instruments, HORIBA et de la plateforme Lasers, Optiques & Spectroscopies. Une visite guidée des installations est également prévue et vous offrira une occasion exclusive de découvrir comment les capacités de pointe et l’expertise de la plateforme peuvent soutenir vos recherches et votre innovation.
Les présentations se dérouleront en anglais, et les questions pourront être posées et répondues en anglais ou en français lors des sessions de questions-réponses. Les ateliers pratiques pourront se dérouler en anglais, en français ou en néerlandais.
Cet événement permet aux doctorants d'obtenir 1 crédit ECTS ; une attestation de participation peut également être délivrée sur demande.
La matinée se clôturera par un networking lunch et l'après-midi se clôturera par un drink.
La participation à cet évènement se fait exclusivement sur inscription après invitation.
Soutenance publique de thèse de doctorat en Sciences chimiques - Lou D'haese
Raman Optical Activity Signatures of Flexible Systems – Main Focus on Cryptophane Derivatives.
Résumé
In this work, I aimed at simulating accurately the Raman optical activity (ROA) signatures of flexible solute molecules in their environment. Indeed, these systems are quite challenging due to potentially huge number of conformers, i.e. local minimum on the potential energy surface (PES). Moreover, the environment can drastically change the PES which can be observed on the experimental ROA spectra that vary quite a lot with the conformation of the molecule and its surroundings. In order to tackle this issue, we have designed a hierarchy of methodology named M1, M2, M3. In M1 and M2, the so-called static approach is used: one or more conformers are found, their geometry are reoptimized at the Density Functional Theory (DFT) level, and their vibrational signatures are simulated, usually at the harmonic approximation. The initial list of conformers was obtained by using the CREST algorithm. In M1, the solvent is considered implicitly while in M2, explicit solvent molecules are added around the solute molecule. In M3, we perform an ab-initio molecular dynamics of the solute molecule surrounded by explicit solvent molecules. The spectrum is obtained by evaluation time-correlation functions along the trajectory. Our first systems of interest were cryptophane derivatives. They are flexible cage-like systems made of two hemispheres connected by three -O-(CH2)n-O- (denoted Cr–nnn) linkers that exhibit chiroptical properties. For Cr–111, the smallest cryptophane possible, M1 methodology gave a good agreement with respect to experiment, especially in the fingerprint region. However, we have demonstrated that the relative ratio between the different conformers was strongly impacted by the choice of the exchange-correlation (XC) functional in our DFT calculations demonstrating the sensibility of the description of the PES. Cr–222 molecules have shown to be more flexible, as demonstrated by a greater number of significant conformers. The overall agreement with experiment was also satisfactory. Finally, to test our different approaches (M1-M3), I have performed new ROA measurements of amino acids in water at the University of Bordeaux in the lab of Dr. Daugey. When compared to our simulations, we have clearly seen an improvement on the ROA signatures when explicit water molecules are added in our simulations (M2 vs M1). Unfortunately, M3 method did not perform as expected and further investigations are needed. Overall, I have shown that the PES as described by our various methodologies is very sensitive to various parameters of the simulation such as the XC functional, the number and position of explicit solvent molecules, … and that all these impact strongly the simulated ROA signatures.
Jury
- Prof. Francesca CECCHET (UNamur), Présidente
- Prof. Vincent LIÉGEOIS (UNamur), Secrétaire
- Prof. Benoît CHAMPAGNE (UNamur)
- Prof. Carine CLAVAGUÉRA (Université Paris-Saclay)
- Dr Nicolas DAUGEY (Université de Bordeaux)
Soutenance publique de thèse de doctorat en sciences physiques - Valentin Job
Development of Antipathogenic Surfaces by Magnetron Sputtering: From Fundamental Mechanisms to Antibacterial and Antiviral Applications
RésuméFrequently touched surfaces (fomites) serve as reservoirs for pathogens, including bacteria and viruses, and act as vectors for contact-mediated transmission. They contribute to the spread of healthcare-associated infections and represent an increased risk during epidemic outbreaks, as highlighted by the COVID-19 pandemic. This thesis focuses on the development of antimicrobial coatings releasing silver (Ag) and copper (Cu), deposited by magnetron sputtering. Three coating matrices were investigated: hydrogenated amorphous carbon with or without chromium (a-C:H and Cr/CrN/a-CrC:H) and titanium aluminum nitride (TiAlN). Antibacterial performance was evaluated against Staphylococcus aureus and Escherichia coli. To assess long-term efficacy, the antibacterial properties of the coatings were investigated through successive bacterial exposure cycles. Antiviral activity was evaluated against porcine respiratory coronavirus (PRCV), a member of the Orthocoronavirinae subfamily to which SARS-CoV-2 also belongs. For this purpose, a rapid high-throughput antiviral screening assay was developed. This original method represents a promising approach for the standardized evaluation of antiviral surfaces. In addition to antimicrobial activity, the coatings were required to exhibit adequate mechanical properties and an attractive black appearance suitable for high-touch surfaces. The combination of Ag and Cu exhibited a synergistic effect, enhancing antimicrobial activity and broadening the spectrum of targeted pathogens. Optimization led to a TiAlN coating containing 0.9 at.% Ag and 1.7 at.% Cu, which provided the best compromise between mechanical, antibacterial, and antiviral performances. Tribological wear tests confirmed the preservation of its antimicrobial efficacy for up to two years. Perspectives for the further development and scientific validation of this prototype are discussed. Jury
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