Développement d’un électrolyte à base de liquide ionique pour accumulateur au Lithium

In lithium ion batteries, the electrolyte plays an important role because its physicochemical and electrochemical properties determine their efficiency. Currently, the used organic electrolytes induce difficulties in the manufacturing and the use of the battery (volatile and flammable components). New electrolytes based on molten salts at room temperature, called ionic liquids, are safer potential candidates (low flammability, low vapor pressure, high flash point) with a wide electrochemical window. The first stage of this PhD was to design new and more efficient synthetic routes, taking into account the environmental requirements (waste minimization, no solvent) and allowing the elaboration of ionic liquids with high purity> 99.5%, compatible with an industrial production. New ionic liquids derived from imidazolium cation were then designed in order to modulate their physicochemical properties, and to optimize their performance in batteries. They were evaluated in various battery technologies (Graphite/LiFePO4) and (Li4Ti5O12/LiFePO4) under different experimental conditions, 298 K and 333 K, when the conventional lithium ion batteries (organic electrolyte) are used only under 313 K. This PhD work has identified the chemical modifications to yield the most promising electrolytes, and highlighted the importance of the study on the understanding of ionic liquid/electrode interphase phenomenaDans les accumulateurs au lithium, l'électrolyte joue un rôle important car ses propriétés physicochimiques et électrochimiques conditionnent l'efficacité du générateur électrochimique. Actuellement, les électrolytes organiques utilisés induisent des difficultés pour la mise en oeuvre et l'utilisation de la batterie (composants volatils et inflammables). De nouveaux électrolytes à base de sels fondus à température ambiante, dit liquides ioniques, sont des candidats potentiels plus sécuritaires (faible inflammabilité, basse pression de vapeur saturante, point éclair élevé), qui présentent en outre une large fenêtre électrochimique. Dans un premier temps, le travail de thèse a été de concevoir de nouvelles voies de synthèses plus économes, tenant compte des exigences environnementales (limitation des déchets, pas de solvant) et proposant des liquides ioniques de haute pureté >99.5% compatibles avec une production industrielle. De nouveaux liquides ioniques dérivés du cation imidazolium ont alors été conçus afin de moduler leurs propriétés physicochimiques et optimiser leurs performances dans les batteries. Ils ont été évalués dans diverses technologies de batteries (Graphite/LiFePO4) et (Li4Ti5O12/LiFePO4) dans différentes conditions expérimentales, à 298 K et 333 K, cette dernière température étant proscrite pour les batteries conventionnelles. Ce travail de thèse a permis d'identifier les modifications chimiques pour conduire aux électrolytes les plus prometteurs et à mis en exergue l'importance de l'étude de la compréhension des phénomènes d'interphase liquides ioniques/ électrode

Metal-catalyzed asymmetric sulfoxidation, epoxidation and hydroxylation by hydrogen peroxide

International audienceThe development of environmentally benign reactions is an important goal in synthetic organic chemistry and chemical engineering. However, catalytic enantioselective oxidations using transition-metal complexes are limited when the oxidant is hydrogen peroxide. The two main difficulties of using hydrogen peroxide in the presence of transition metal complexes are the homolytic cleavage generating OH radicals and the catalase reaction with formation of dioxygen. The current applications of asymmetric sulfoxidation, epoxidation, dihydroxylation of alkenes and hydroxylation will be herein reported. Use of non-heme systems will be presented. The possibility of asymmetric oxidation catalyzed by metalloporphyrins will also be discussed

Nitration of Halterman porphyrin: a new route for fine tuning chiral iron and manganese porphyrins with application in epoxidation and hydroxylation reactions using hydrogen peroxide as oxidant

International audienceA methodology is reported for the regioselective nitration of the phenyl groups of Halterman porphyrin, using NaNO2. These nitro-porphyrins can be reduced to aminoporphyrins and then N-dimethylated to give new optically active porphyrins. Applications to the asymmetric epoxidation of styrene derivatives by H2O2 to give optically active epoxides (ee up to 60%) and hydroxylation of alkanes to give optically active secondary alcohols (ee up to 69%) were carried out in organic solvents (dichloromethane/methanol) using chiral iron and manganese porphyrins as catalysts

Diazo ester insertion in N-H bonds of amino acid derivatives and insulin catalyzed by water-soluble iron and ruthenium porphyrin complexes (FeTSPPCl) as application of carbenoid transfer in aqueous media

International audienceThe metal complex FeTSPPCl (5,10,15,20-tetrakis)-(4-sulfonato-phenyl)-porphyrin-iron(III) chloride is an active catalyst for carbenoid insertion in N–H bonds of aminoacid derivatives in aqueous media. A variety of diazoacetates and methyl diazophosphonate were used as carbenoid precursors. The commercially available iron porphyrin complex can also selectively catalyze alkylation of the N-terminus of insulin (chain B

Solvents for Carbon Dioxide Capture

Anthropogenic CO2 emissions are considered the major contributor of greenhouse gas emissions worldwide. The mitigation of this kind of CO2 emissions relies on a portfolio of alternatives where CO2 absorption appears as the nearest approach to be applied at industrial scale. Researchers have been focused on developing new formulations of solvents to make more competitive CO2 absorption as a carbon capture and storage (CCS) technology. In this sense, this chapter summarizes both the conventional solvents and the most recent investigations on this field. Chemical absorption is more suitable for a lot of industrial process due to the flue gas conditions: ambient pressure, low CO2 concentration and large volume. Therefore numerous novel solvents came up in recent years and they are further discussed in this chapter. The most recent solvents, their mechanisms and kinetics and the advantages and disadvantages are also included. Finally, physical solvents are adequate in high CO2 partial pressure applications and they are reported in the last section. Although physical absorption field is constrained to high-pressure flue gas, physical solvents provided higher performance in CO2 separation process and their characteristics are also summarized.Ministerio de Economía y Competitividad OXYSOLVENT Pro. CTM-2014-58573-RFondo Europeo de Desarrollo Regiona

Mediating gel formation from structurally controlled poly(electrolytes) through multiple "head-to-body" electrostatic interactions

Tuning the chain-end functionality of a short-chain cationic homopolymer, owing to the nature of the initiator used in the ATRP polymerisation step, can be used to mediate the formation of a gel of this poly(electrolyte) in water. While a neutral end group gives a solution of low viscosity, a highly homogeneous gel is obtained with a phosphonate anionic moiety, as characterized by rheometry and diffusion NMR. This novel type of supramolecular control over poly(electrolytic) gel formation could find potential use in a variety of applications in the field of electroactive materials

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Catalysis with metalloporphyrins : asymmetric oxidation and carbene transfer reactions

La mission centrale de la chimie verte est d'inventer de nouveaux procédés non polluants pour remplacer les technologies peu favorables à l'environnement. L'emploi de métaux de transition relativement non toxiques en quantités catalytiques associés à des ligands chiraux a permis de réaliser une avancée dans le domaine de la synthèse asymétrique. Dans ce travail, nous avons mis en évidence la possibilité de l'utilisation du peroxyde d'hydrogène, un oxydant vert et économique, en association avec des métalloporphyrines hydrosolubles (Fe, Mn) pour effectuer des réactions d'oxydation asymétrique (sulfoxydation, époxydation et hydroxylation). Ces systèmes représentatifs d'un modèle de l'effet « shunt » des enzymes monooxygénases dérivées de la famille cytochrome P450 sont très efficaces. Ils conduisent dans certains cas à des excès énantiomériques élevés (82%). D'autre part, nous avons développé les réactions de transfert de carbènes dans l'eau (insertion N-H et cyclopropanation asymétrique) catalysées par des porphyrines de fer. L'utilisation du fer comme métal a permis de surmonter plusieurs limites souvent rencontrées avec d'autres métaux (Ru, Rh) lors des réactions de transfert de carbènes dans l'eau. Comme application de la réaction d'insertion N-H, nous avons réalisé la bio-conjugaison régiosélective de l'insuline avec une conversion très élevée (90%).The goal of green chemistry is to promote the research and the development of innovative chemical technologies in order to reduce the contamination of environment. Significant progress in this field has been made by using relatively non toxic transition metal and chiral ligands to catalyze enantioselective transformations. In this work, we have reported the combination of hydrogen peroxide as environmentally benign and atom-economically oxidant with water-soluble metalloporphyrins (Fe, Mn) for the asymmetric oxidation of sulfides, alkenes and C-H bonds. These catalytic systems widely studied as models of cytochrome P450, gave high enantiomeric excesses (ee up to 82%). In the other hand, we have developed carbene transfer reactions in water as « green » solvent catalyzed by water soluble iron porphyrins. This metal (Fe) has been found to overcome many limitations related to the use of other metals (Ru, Rh) in aqueous media. As an application of N-H insertion reaction, the regioselective bio-conjugation of insulin has been demonstrated with high conversion (90%)

Catalyse avec des métalloporphyrines : oxydation asymétrique et transfert de carbènes

The goal of green chemistry is to promote the research and the development of innovative chemical technologies in order to reduce the contamination of environment. Significant progress in this field has been made by using relatively non toxic transition metal and chiral ligands to catalyze enantioselective transformations. In this work, we have reported the combination of hydrogen peroxide as environmentally benign and atom-economically oxidant with water-soluble metalloporphyrins (Fe, Mn) for the asymmetric oxidation of sulfides, alkenes and C-H bonds. These catalytic systems widely studied as models of cytochrome P450, gave high enantiomeric excesses (ee up to 82%). In the other hand, we have developed carbene transfer reactions in water as « green » solvent catalyzed by water soluble iron porphyrins. This metal (Fe) has been found to overcome many limitations related to the use of other metals (Ru, Rh) in aqueous media. As an application of N-H insertion reaction, the regioselective bio-conjugation of insulin has been demonstrated with high conversion (90%).La mission centrale de la chimie verte est d'inventer de nouveaux procédés non polluants pour remplacer les technologies peu favorables à l'environnement. L'emploi de métaux de transition relativement non toxiques en quantités catalytiques associés à des ligands chiraux a permis de réaliser une avancée dans le domaine de la synthèse asymétrique. Dans ce travail, nous avons mis en évidence la possibilité de l'utilisation du peroxyde d'hydrogène, un oxydant vert et économique, en association avec des métalloporphyrines hydrosolubles (Fe, Mn) pour effectuer des réactions d'oxydation asymétrique (sulfoxydation, époxydation et hydroxylation). Ces systèmes représentatifs d'un modèle de l'effet « shunt » des enzymes monooxygénases dérivées de la famille cytochrome P450 sont très efficaces. Ils conduisent dans certains cas à des excès énantiomériques élevés (82%). D'autre part, nous avons développé les réactions de transfert de carbènes dans l'eau (insertion N-H et cyclopropanation asymétrique) catalysées par des porphyrines de fer. L'utilisation du fer comme métal a permis de surmonter plusieurs limites souvent rencontrées avec d'autres métaux (Ru, Rh) lors des réactions de transfert de carbènes dans l'eau. Comme application de la réaction d'insertion N-H, nous avons réalisé la bio-conjugaison régiosélective de l'insuline avec une conversion très élevée (90%)