PhD student in polymer physical chemistry (M/F)

Job Description

Thesis Subject

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 pharmaceutical, cosmetic, and food 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-corona structures, namely complex coacervate core micelles, 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. Subsequently, bio-based co-assemblies will be developed through the functionalization of polysaccharides and their complexation with proteins.
The candidate will be responsible for formulating water-in-water emulsions, for which they will have previously determined the phase diagram, in the presence of complex coacervate core micelles. The latter will be prepared and characterized thoroughly both in bulk and at the interface using scattering techniques and cryo-transmission electron microscopy in collaboration with a postdoctoral researcher in charge of the synthesis of the copolymers. The goal is to understand the relationship between the structure of the co-assemblies (morphology, size, core-to-shell ratio) and their stabilizing properties. We thus aim to gain a better understanding of the mechanisms involved in the stabilization of water-in-water emulsions by soft colloids that can undergo dynamic conformational changes when at the water-water interface.
The candidate must hold a master's degree or an engineering degree in chemistry, physical chemistry, and/or physics, with a specialization in polymers, soft matter, or formulation. Experience in structural characterization (scattering, microscopy) or in the formulation of dispersed systems would be a plus.

Your Work Environment

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, assistant professor at Sorbonne University, and Cécile Monteux, CNRS research director. 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.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions