Soutenance publique de thèse de doctorat en Sciences chimiques - Loraine SOUMOY
Silica-based nanotubes and hollow nanospheres: a transversal approach to understand their synthesis mechanism followed by applications in catalysis and drug release
Date : 14/09/2023 15:00 - 14/09/2023 18:00
Lieu : CH01
Orateur(s) : Loraine Soumoy
Organisateur(s) : Carmela Aprile
Jury
- Prof. Stéphane VINCENT
(département de chimie, UNamur), président
- Prof. Carmela APRILE
(département de chimie, UNamur), promotrice et secrétaire
- Prof Cédric BOISSIÈRE (Laboratoire de chimie de la matière condensée, Sorbonne Université)
- Prof. Damien DEBECKER (Institute of Condensed Matter and Nanosciences, UCLouvain)
- Prof. Michel DUSSELIER (Sustainable Catalysis and Engineering, KULeuven)
- Prof. Sophie HERMANS (Institute of Condensed Matter and Nanosciences, UCLouvain)
Résumé
The development and deep understanding of materials with a high application potential represents a field of great interest. If considering chemical processes, the development of efficient methods based on the use of renewable or waste as starting materials while reducing energy consumption and waste generation emerged as a necessary achievement. In this context, the development of heterogeneous catalysts that can be easily separated from the reaction mixture, reused in multiple cycles or even implemented in continuous flow processes, will contribute to the sustainability of the chemical transformation. As such, there is a strong need to develop and more importantly, enhance our fundamental understanding on the synthesis and performances of new materials evolved in biomass upgrading processes.
Among the possible candidates, the thesis focused on porous low dimensional silica-based nanostructures presenting targeted morphology; nanotubes and hollow nanospheres. Their low dimensionality and mesoporosity are ideal features for their application as heterogeneous catalyst or vehicle for drug release, for example. To reach an accurate control of their morphology, the formation mechanism of silica nanotubes and hollow nanospheres is first investigated. Then, silica nanotubes and nanospheres are applied for the enhanced release of curcumin. The possibility to insert heteroelement such as Hf, Ga and Zr with the targeted Si/M ratio, in the structure of silica nanotubes and/or nanospheres is deeply studied across the manuscript. M-doped silica nanostructures show Brønsted and Lewis acid sites, useful for the conversion of biomass derivatives. Excellent catalytic activities were reported in the conversion of glycerol into solketal and the conversion of ethyl levulinate to ɣ-valerolactone. By comparing the catalytic activity of M-doped nanotubes and hollow nanospheres, it is also shown that the morphology of a porous low D silicate is a key factor determining its catalytic activity.
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