Description du sujet de thèse

With a view to reducing the carbon impact of construction materials (Portland cement alone is responsible for 7% of global GHG emissions), this project will explore the potential of a new portfolio of macromolecules based on a biosourced synthon that has been very abundant up to now, but has virtually no current uses: dimethylsulfopropionate (DMSP). DMSP is an essential link in the natural sulfur cycle, and is the most abundant organic sulfur product on earth (~109 t/year). The thesis will explore the adsorption, deflocculation and coating properties of these new molecules. These properties will be exploited in the context of low-carbon building materials: deflocculation of calcined clays in compound cements; dispersion, gelation and water resistance of clay materials for raw earth construction. The performance of these new ternary sulfur-bearing molecules will be compared with the anionic polycarboxylates and cationic polyamines currently used by industry. This thesis will cover all scales, from chemical synthesis through molecular and macroscopic characterization to properties of use in civil engineering. An assessment of the environmental impact of using this new synthon will be carried out in collaboration with a colleague from ESPCI Paris.
We are therefore looking for a candidate for this thesis in Paris, interested in innovative experimental work at the interface between fundamental and applied research. The profile sought is that of a physical chemist with an M2 or engineering degree in chemistry or physics.

Contexte de travail

This project is built around two twin theses conducted simultaneously and in collaboration at ESPCI Paris and the University of Sherbrooke. The thesis at UdS will focus on setting up polymerization and coupling protocols to obtain various cationic or zwitterionic surfactants, oligomers and polymers. The candidate should therefore be comfortable with the idea of collaborative work shared between three disciplines (physics, chemistry and civil engineering) and two laboratories on opposite sides of the Atlantic (France and Quebec). The thesis is based in Paris at the Soft Matter Science and Engeering laboratory of ESPCI Paris PSL (UMR CNRS SIMM) (simm.espci.fr), but stays in Quebec in Prof. Claverie's lab at Sherbrooke University (lab-claverie.ca/) will be essential.