11/03/2019 Offres d'emploi

Offre de thèse - IMRCP - 2019

Nanoparticles-metal ions-polymers hybrid assemblies for biology at Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique (Toulouse)

MERS funding, 1300€/month for 3 years, deadline for the application April 26th

Keywords : hybrid colloidal assemblies, nanoparticles, polymers, block copolymers, metal ions

Scientific context

Inorganic-organic polymer hybrid assemblies represent an important class of materials with a broad spectrum of properties. In particular, they can be triggered by various stimuli like magnetic, electrical, photonic or from changing of physicochemical and thermodynamic surrounding environment.[1] The established relationship between theses assemblies and the mechanisms ruling the living structures, make them perfect models for a deeper understanding of fundamental biological processes.[2] Their study has been a key activity of the Ideas team at the IMRCP Laboratory, for several years.

In this context, hybrid colloids called “hybrid polyionic complexes” are actively developed in the team. They are obtained by spontaneous assembly of a copolymer bearing an ionisable negative charged block by metallic ions. Complexes of Gd3+/PEO6k-b-PAA3k (poly(ethylene oxide)-block-polyacrylic acid) were thus developed as a new generation contrast agent for MRI.[3]

Now, we would like to associate to these assemblies, nanoparticles with plasmonic properties (gold, silver) in order to enlarged the spectrum of their properties. A strategy for elaborating these new assemblies is shown in the illustrating figure.

Thesis topic

The aim is to design multi-component co-assemblies mixing polymers, metal ions and nanoparticles. Their size, composition and surface chemistry should be easily controlled by weak interactions. The impact of these interactions on the physical and physicochemical properties of these assemblies will be studied. Depending on the achieved properties (optic, responding stimuli) we will finally evaluate the potential of these assemblies to be applied in biology.

As part of the project several strategies to access hybrid assemblies are envisaged:
1. A three-component formulation - polymer, metal ion and nanoparticle.
2. Formation of hetero-metallic poly-ionic hybrid complexes, followed by a selective reduction of the ions of the most electronegative metal (gold, silver)[4,5] as shown in the figure.
3. The assembly of nanoparticles and / or metal ions at the interface of emulsions
formed by the polymers.

Profile of the candidate

We are looking for a student with a Master of Science or engineering degree, motivated by the project. We ask for a rigorous, autonomous and dynamic student with high scientific curiosity. He / she should have good English skills. The student will be part of the IDeAS team, will benefit from the instruments for the synthesis and physicochemical characterization of materials of the laboratory and will have access to the technical platforms of the Toulouse Institute of Chemistry. The student will receive a multidisciplinary training combining synthesis, and physicochemical characterization of nanoparticles, polymers, as well as in self-assembly.

Contact

Diana Ciuculescu-Pradines et Jean-Daniel Marty
e-mail : ciuculescu-pradines@chimie.ups-tlse.fr et marty@chimie.ups-tlse.fr

 

Bibliographic references

1. Grzelczak, M., Liz-Marzán, L. M. & Klajn, R. Stimuli-responsive self-assembly of nanoparticles. Chemical Society Reviews (2019). doi:10.1039/C8CS00787J
2. Grzelczak, M. Colloidal systems chemistry. Replication, reproduction and selection at nanoscale. Journal of Colloid and Interface Science 537, 269–279 (2019).
3. Frangville, C. et al. Assembly of Double-Hydrophilic Block Copolymers Triggered by Gadolinium Ions: New Colloidal MRI Contrast Agents. Nano Letters 16, 4069–4073 (2016).
4. Seo, E.; Kim, J.; Hong, Y.; Kim, Y. S.; Lee, D.; Kim, B.-S. Double Hydrophilic Block Copolymer Templated Au Nanoparticles with Enhanced Catalytic Activity toward Nitroarene Reduction. The Journal of Physical Chemistry C, 117 (22), 11686–11693 (2013).
5. Seo, E.; Lee, S.-H.; Lee, S.; Choi, S.-H.; Hawker, C. J.; Kim, B.-S. Highly Stable Au Nanoparticles with Double Hydrophilic Block Copolymer Templates: Correlation between Structure and Stability. Polymer Chemistry, 8 (31), 4528–4537 (2017).

 

Toutes les informations résumées dans le fichier PDF.