Missions

COFs were first developed in 2005. They are porous, organic materials made up of dynamic covalent bonds that give them good self-correcting capabilities during their formation, resulting in highly crystalline structures. The geometry of the building blocks and the orientation of their reactive groups determine the dimensions and topology of the network and define the pore size. No other multidimensional polymerization strategy currently allows the structure of a network to be predicted and adjusted to such a level. Thanks to their properties (tunable porosity, high specific surface area and lightness), COFs are envisaged for numerous applications in storage, molecular separation, catalysis, sensing, optoelectronics, encapsulation and delivery of bioactive molecules.. However, there are still bottlenecks limiting further development. Most COFs are isolated as insoluble powders with small crystalline domains, typically on the order of 50 nm. A few studies report the production of large single-crystals of COF (more than 15 microns), essentially restricted to imine-linked COF. Nevertheless, they all rely on optimization of synthesis conditions (by modifying the nature of the catalyst, for example) and therefore lead to particularly long reactions despite some gradual improvements (from several months to a few days of synthesis). Very recently, we developed a new class of hybrid materials by combining COFs with macromolecular chemistry. The polymer was used, in the presence of COF building blocks, to facilitate the formation of COF-polymer hybrid vesicles. We then discovered that the addition of a small molecule could induce a very rapid and radical change in morphology. Within minutes, the vesicles transform into monocrystalline micro-rods. For the moment, the underlying mechanism is not fully understood. An in-depth study of this phenomenon will enable us to better manipulate it. This fast formation of large single-crystal COF via a supramolecular approach will represent a definite step forward in the field to gain control over the time-scale and the structural features of the fully organic matter

Activités

Synthesis of COF-polymer hybrid particles and study of their reorganization using various characterization methods.

Compétences

A strong interest in material science and characterization techniques (scattering techniques, X-ray diffraction, electron microscopy, confocal microscopy) is desirable. Skills in organic and polymer synthesis are a plus.

Contexte de travail

Postdoctoral researchers will have access to all the platforms available at the Chevreul Institute in Villeneuve d'Ascq and, more generally, to the facilities on the Cité Scientifique campus.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.