Missions

Water-in-water emulsions are ternary mixtures consisting of water and two incompatible hydrophilic polymers. Although they have great potential for use in the formulation of compartmentalized food, cosmetic, and pharmaceutical products, their use is limited by their inherent instability. In the last decade, significant efforts have been made to develop stabilizers, but the link between their chemical composition and their ability to adsorb and wet the water/water interface remains poorly understood. The MUSCADET project aims to develop multi-scale compartmentalized aqueous systems by adsorbing particles consisting of two polyelectrolytes with opposite charges functionalized by neutral hydrophilic polymer segments, which form core-crown structures, namely micelles with a complex coacervate core, at the interface. The composition of these colloidal particles will be adapted to optimize their ability to stabilize water-in-water emulsions, adopting a strategy based on well-defined structures through the use of synthetic block copolymers. These particles will provide additional functionality to the systems, in particular thanks to their core composed of a polyelectrolyte complex, which is by itself an additional compartment, smaller in size than the emulsion droplets but close to them thanks to their adsorption at the interface.

Activities

The candidate will be responsible for synthesizing double-hydrophilic block copolymers by controlled radical polymerization (ATRP and RAFT) in order to develop well-defined complex coacervate core micelles. The macromolecular architecture of these copolymers will be precisely varied and characterized (in particular by NMR and SEC). The goal will be to develop a library of these particles with different sizes, core/corona ratios, morphologies, and corona compositions. The co-assemblies will be characterized by static and dynamic light scattering as well as by cryo-transmission electron microscopy.

Skills

The candidate must hold a PhD in polymer chemistry and/or physical chemistry. Experience in macromolecular synthesis, particularly using controlled radical polymerization (ATRP and/or RAFT), and in characterization in the solution state (1H and 13C NMR, size exclusion chromatography) is essential. Skills in structural characterization (scattering techniques, microscopy) would be appreciated.

Work Context

The research work will be carried out in the Soft Matter Science and Engineering Laboratory (SIMM: https://www.simm.espci.fr/), under the supervision of Théo Merland and Nadège Pantoustier, lecturers at Sorbonne University. The SIMM laboratory is a CNRS Joint Research Unit located at ESPCI Paris-PSL, and also depends on Sorbonne University. The research conducted at the laboratory focuses on the development and study of complex fluids and soft materials, and benefits from the expertise and equipment for macromolecular synthesis, multi-scale mechanical and structural studies, and the physicochemical characterization of these systems.

Constraints and risks

No particular constraints or risks.