Development of methods for U quantification in cells after exposure to uranium
This project fits into the transverse Toxicology Program, led by CEA, whose purpose is to address by multidisciplinary approaches, the potential effects on living organisms of elements of strategic interest to the CEA. The objective is to provide some understanding on the mechanisms of uranium toxicity and behavior, in connection with its speciation in cells. Indeed, the radionuclides speciation governs their bioavailability, accumulation, biodistribution, toxicity, detoxification mechanisms and their interaction at the molecular level.
The post-doctoral project (12 months) consists in:
- Developing methods to quantify U accumulated in the cells as well as endogenous content of trace elements after exposure of cells to uranium.
- Developing methods to determine the precise isotopic composition of U in the cells after their exposure.
The candidate will be in charge of developing chemical purification and measurement methods for precise elemental and isotopic analyses. The analyses will be performed using inductively coupled plasma quadrupole mass spectrometer (ICP- MS Q) or inductively coupled plasma multi- collection mass spectrometer of the latest generation (ICP- MS MC), to achieve the lowest level of uncertainties.
Carbon nanotubes grafting for positive electrodes of lithium/sulfur cells
In a view to develop electric vehicles, researches on lithium batteries are now focusing on sulfur active material. Indeed, this new system should allow to produce cheap and high energy batteries of about 600 Wh/kg. While being developed for more than 40 years, the limitations of such a system are still quite problematic: elemental sulfur is an electronic insulator, sulfur and intermediate lithium polysulfides are soluble in the electrolyte and final discharge product Li2S is non-soluble and insulating too.
This post-doctoral position will thus aim at improving the performances of the sulfur positive electrode, by combining :
- Carbon nanotubes that will allow to improve the electronic conductivity of the positive electrode, as well as to provide a substrate for sulfur grafting
- Disulfide functions that will be grafted on the nanotubes. Thanks to this chemical grafting of active material, the electrochemical reaction would occur without leading to sulfur and polysulfides dissolution, thus leading to higher capacity and cyclability along with lower self-discharge.
Immunotargeting of based-organic nanoparticles for clinical applications
The project aims to tailor-make based-organic nanocarrier enabling to target antibodies to increase the efficacy of therapy (more particularly mantle cell lymphoma) for clinical applications. Our group has developed a unique delivery system based on lipid nanoparticles for imaging and therapeutic purposes since the last 6 years. Based on this technology, the candidate will:
- optimize the targeting of specific ligands into organic nanoparticles (bioconjugate chemistry)
- optimize the encapsulation of drugs in the immunotargeted nanoparticles
- assess the physico-chemical characterization of all nanoparticles
- evaluate the binding affinity of doped and targeted nanoparticles
Synthesis and characterization of amino-phosphorous ligands for extraction of uranium in a sulfuric medium with a “liquid / liquid” process
The development of new and more effective extractants than those currently used is therefore an important issue for the mining of uranium. In particular, access to specific chelating systems with high affinity for uranium with selective properties in regards to competitor’s ions and less susceptible to hydrolysis remains a challenge.
Recently, new bifunctional molecules amio-phosphine oxide type has shown their potential for the extraction of uranyl in sulfuric media with excellent properties in terms of affinity and selectivity for the metal.
The objective of this postdoctoral fellowship will be to optimize this family of ligands, with the development of concise and efficient routes for their chemical and suitable for the preparation of large quantities of extractant for further study the optimization of the process.
Multiscale approach of f elements aqueous solutions modeling
A post-doctoral position is available for one year at CEA-Marcoule
The study will be the modeling of concentrated aqueous phases of heavy metal salts using both microscopic and mesoscopic modeling.
Separation processes for heavy metals recycling usually use liquid-liquid extraction with the transfer of ionic species from a concentrated aqueous phase to an organized organic phase.
This post-doctoral research subject relates to the chemical properties of these processes, and especially to the characterization of the aqueous phase using as accurate as possible models. The goal is to understand the various effects (solvation, electrostatic and van der waals forces, entropy…) influencing the structural and energetic properties of these solutions. A multi-scale approach will be used to study some systems of interest for both fundamental and industrial point of view, the aim being the characterization of these solutions from their molecular structure to their thermodynamic properties. The tools and the approach used here have to be be valid for separative chemistry overall.
This study aims at the chemical synthesis of infrared emitting nanocrystals for integration in LEDs.
These nanocrystals will be characterized by TEM, XRD, EDX, UV-vis, PL, NMR, FTIR. Formulation of colloidal solutions suitable for deposition via inkjet printing.
The candidate will work in the partner lab INAC/LEMOH
Plastic recycling enabled by toxic additives extraction using green solvents
It is important to develop the scientific knowledge and stimulate innovations to recycling Plastics. The extremely large variety of plastic based objects that we use in our daily life are made of a wide range of plastic materials covering many different polymers, many different formulations. Plastics objects are also used for many purposes and there is therefore the need of various ways to collect, sort and treat them.
Methods of recycling of plastics are generally divided into four categories: primary, secondary, tertiary, and qua-ternary (see Figure 9). Primary recycling or closed loop recycling method is considered when the materials after recycling present equal or improved properties compared to the initial or virgin materials. When the recyclates present a decrease in the properties level, one may spook about secondary or down-cycling method. In tertiary (also known as chemical or feedstock) recycling method, the waste stream is converted into monomers or chemicals that could be advantageously used in the chemical industries. Finally, quaternary (also known as thermal recycling, energy recovery, and energy from waste) recycling method corresponds to the recovery of plastics as energy and is not considered as recycling for Circular Economy.
Various processes can be considered for chemical recycling which present different level of maturity. Hence this project that will study the decontamination of various PVC formulations using green solvents, and more particularly supercritical CO2
This work located in Saclay, France, in the heart of the University Paris-Saclay and will benefit from a very multidisciplinary and international environment.
This work will benefit from the prestigious framework of the France 2030 funding, and more precisely the PEPR Recycling (https://www.cnrs.fr/fr/pepr/pepr-recyclabilite-recyclage-et-reincorporation-des-materiaux-recycles ). It will be supervised by Dr. Jean-Christophe P. Gabriel: linkedin.com/in/jcpgabriel).
New Sustainable Carbon Catalysts for PEMFC
The aim of the project is to develop and test for ORR, a mesoporous and graphitised graphene aerogel based material, presenting a hierarchical structuring allowing a better material transfer and graphitic domains increasing the durability and conductivity of the final material, and functionalised by Pt-NPs.
These graphene-based structures developed at IRIG/SyMMES possess surface chemistries and micro/meso/macro porosities that depend on the synthesis, functionalisation and drying methods used. The aim will be to increase their degree of graphitisation, and then to deposit Pt-NPs by chemical means. The electrocatalytic properties of these materials will then be tested.
Advanced meso-structural characterisation of these materials by scattering (X-ray or neutrons) methods will enable to investigate the structural properties of these new electro-catalysts. These properties will thenbe correlated to their electrocatalytic properties, and performances in fuel cell systems. This knowledge will be gained through ex-situ and operando analyses.