Soutenance de Thèse de Mr Pierre LEGOUT

The May 19, 2021

Synthèse de copolymères fonctionnels amphiphiles appliqués à la cristallisation de particules de carbonate de calcium en milieu CO2 supercritique par un procédé d'émulsification continu et éco-responsable

Directeur de Thèse: Pr Brice Calvignac

Co-directeur de Thèse: Dr Olivier Colombani

Abstract :

In this study, the objective was to develop a new process PCC particle with controlled characteristics (polymorphism, size and structure). The carbonation process is based on the formulation of a water / carbon dioxide supercritical emulsion (W/C) whose stabilization is ensured by the use of an amphiphilic diblock copolymer. First of all, the proposed approach aimed to (i) synthesize by radical polymerization of PDMS13-b-POEGMAx type and (ii) the comparative study of their E / C interfacial activity with commercial Pluronics® copolymers for their use for the emulsion control and the stabilization of the aqueous droplets constituting the site of carbonation. The study of the surfactant behavior of the copolymers was carried out and correlated with the effect of their molecular structure by studying W/C interface and their impact on stabilizing emulsions

It was investigated using an experimental bench developed and tested in the laboratory equipped with a stirred batch reactor for the emulsion visualization, a pendant drop tensiometer and an in situ dynamic light scattering technique. It has been possible to demonstrate the micellar and thermosensitive behavior of of the PDMS13-b-POEGMAx copolymers. Microfluidic bench was developed in order to study the implementation of the carbonation process by continuous emulsification involving copolymers. Different hydrodynamic and pressure conditions and two fluid contacting devices were also investigated with regard to the characteristics of the CCP particles (size, distribution, morphology, polymorphism. 

Keywords : Calcium carbonate, Polymers, Interfacial Tension, Emulsion