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International audience; Hyper-crosslinked polymers (HCPs) are receiving great attention due to their high specific surface area, allowing them to offer high performance in many different applications. However, most of the time, their synthesis requires hazardous and time-consuming protocols, making their implementation and scaling up difficult. To overcome this problem, a relatively old technology such as mechanosynthesis (MS) has gained renewed interest as a greener and faster technology to produce HCPs, which involves much lower energy consumption during the reaction process. In this review, the latest advances on the performance of HCPs based on MS protocols are compiled and analysed, subdivided into those based on Friedel-Crafts alkylation, Scholl coupling reactions and other less common procedures. An analysis of MS versus solvent-based protocols regarding the twelve principles of green chemistry is also reported, as well as a section including a summary of the most recent applications of HCPs. Finally, the use of bio-based precursors for the formulation of HCPs is discussed, thus pooling knowledge for a greener, faster and more widely applicable future development of HCPs.

International audience; Hyper-crosslinked polymers (HCPs), a relatively new type of polymers with inherent porosity and high specific surface area, are of great interest due to their excellent results in many different application areas. These HCPs are typically synthetised via solvent-based protocols such as Friedel-Crafts and Scholl coupling reactions, which are time-consuming and hazardous. In an effort to promote environmentally friendly synthesis routes, this presentation will focus on bringing together the most recent work that formulates HCPs through a greener and faster alternative, mechanosynthesis. An analysis in the light of green chemistry principles has been performed and so, the mechanosynthesis will be compared to current synthesis routes. The main applications of HCPs will also be presented and analyzed in order to give an overview of the potential of HCPs. Finally, the use of biosourced precursors to obtain HCPs will be discussed to provide an alternative route to obtain still more environmentally friendly HCPs. With this work, the authors aim to provide the necessary background for the development of greener alternatives for the synthesis of these remarkable HCPs.

International audience; This study concerns the development of an innovative manufacturing process for oxide-dispersion strengthened steels (hereafter referred to as "ODS") by mechanosynthesis. As part of materials development for Sodium-cooled Fast Reactors (SFR), the aim is to prevent the growth of undesirable micrometric precipitates which can drastically degrade steel's mechanical properties. This new process introduces Y2Ti2O7 pyrochlore oxide nanoparticles directly into Fe-Cr metallic powder through mechanical milling, as compared to the standard Y2O3 + TiO2. This study enables the validation of the method of introducing precipitates in the form of Y2Ti2O7 oxides as an efficient way to obtain competitive ODS steels, with a more homogeneous microstructure, less coarse precipitates and more reliable impact properties compared to the conventional process. Moreover, it reveals the importance of the features of the manufacturing process, particularly of milling intensity and reinforcement rate, on the microstructure and mechanical properties of ODS steel. The results reveal promising perspectives concerning the features of ODS steel manufacturing.

This thesis focuses on the optimization of the syntheses and on the structural characterizations of coordination networks based on octahedral clusters of transition metals and dicarboxylate ligands (terephthalates (T) and fumarates (F)). The synthesis strategy that was adopted consists in reacting by mechanosynthesis strongly polarized units, in particular [{Mo6Bri8}Fa6]2-, with dicarboxylic acids. Due to the polarization of the Mo-F bond, the diacids react with the units [{Mo6Bri8}Fa6]2- to yield the corresponding carboxylates with release of HF. The carboxylates thus formed are linked to the clusters via a Mo-O bond. Two compounds based on chains of clusters linked together by T and F ligands have been synthesized. Partial structural models were obtained from X-ray powder diffraction data. Finally, the synthesis strategy used and the structural analyzes have been validated by calculations devoted to the modeling of the reactivity and of the crystal structures., Ces travaux de thèse portent sur l’optimisation des synthèses et sur les caractérisations structurales de réseaux de coordination à base de clusters octaédriques de métaux de transition et de ligands dicarboxylates (téréphtalates (T) et fumarates (F)). La stratégie de synthèse retenue a consisté à faire réagir par mécanosynthèse des motifs fortement polarisés, en particulier [{Mo6Bri8}Fa6]2-, avec des diacides carboxyliques. En raison de la polarisation de la liaison Mo-F, les diacides réagissent avec les motifs [{M6Bri8}Fa6]2- pour donner les carboxylates correspondants avec libération de HF. Les carboxylates ainsi formés se lient aux clusters via une liaison Mo-O. Deux composés basés sur des chaînes de clusters reliés entre eux par des ligands T et F ont été synthétisés. Des modèles structuraux partiels ont été obtenus à partir des données de diffraction de rayons X par la poudre enregistrées au laboratoire et au synchrotron. Enfin, la stratégie de synthèse utilisée et les analyses structurales ont été validées par des calculs de modélisation de réactivité et de structures cristallines.

Led by the electrification of transport and the growing share of renewable energies in energy production, the energy storage market is constantly growing. Currently, lithium-ion technology is the most efficient on the market, but it seems to have reached its limits in the last few years. Indeed, lithium-ion batteries are struggling to meet the new requirements of power, lightness and especially present some problems in terms of security and lithium supply. The design of new electrochemical storage systems such as all-solid-state sodium batteries paves the way to more efficient and safer batteries without lithium. One of the key materials in this new generation all-solid-state battery is the solid electrolyte separating the two electrodes. The research work presented in this manuscript takes place in this context, by studying glass and glass-ceramic materials that can be used as solid electrolyte. The formulation of new sodium sulfide glasses has been carried out in order to study their ionic and electronic conduction properties and to determine their potential application in all-solid-state batteries. In order to improve these characteristics, additional research was carried out on the impact of crystallization and the addition of chlorine on the conduction properties. Finally, original works on the nitriding of sulfur-based glasses has been undertaken with the aim of lowering the weight of the battery and potentially improving the conduction properties of these electrolytes., Entraîné par l’électrification des transports et la part grandissante des énergies renouvelables dans la production d’énergie, le marché du stockage de l’énergie ne cesse de croître. Actuellement, la technologie lithium-ion est la plus performante du marché, mais semble atteindre ses limites depuis quelques années. En effet, les batteries lithium-ion peinent à répondre aux nouvelles exigences de puissance, de légèreté et posent surtout des problèmes en terme de sécurité et d’approvisionnement en lithium. La conception de nouveaux systèmes de stockage électrochimique tel que des batteries tout-solide au sodium ouvre alors une possibilité pour confectionner des batteries plus performantes et plus sûres tout en s’affranchissant du lithium. L’un des matériaux clé dans ce batteries nouvelles génération solide est l’électrolyte solide séparant les deux électrodes. C’est dans ce contexte que s’inscrivent les travaux de recherche présentés dans ce manuscrit, en étudiant des matériaux vitreux et vitrocéramiques pouvant être utilisés en tant qu'électrolyte solide. La formulation de nouveaux verres de sulfures au sodium a été réalisée afin d’étudier leurs propriétés de conductions ioniques et électroniques et de déterminer leur potentielle application en batterie tout-solide. Dans un soucis d’amélioration de ces caractéristiques, des recherches ont été menées sur l’impact de la cristallisation et l’ajout de chlore sur les propriétés de conduction. Enfin, des travaux inédits sur la nitruration de verres à base de soufre ont été entrepris dans le but d’alléger la batterie et de potentiellement améliorer les propriétés de conduction de ces électrolytes.

International audience; (R)-1,2-Diaminobicyclo[2.2.2]octane was used as a starting material for the preparation, in solution or in a ball mill, of a salen ligand. Five metal salen complexes were prepared in high yield and their cytotoxic activities were evaluated against the Human Colon cancer HCT116 cell lines. The original manganese salen complex displayed the highest activity with a potency 16 fold higher than that of cisplatin, demonstrating the benefit of the bridging backbone compared to other salen systems. An alternative preparation route for this complex by mechanochemistry was also performed.

Geopolymers are inorganic materials made from compounds of natural origin (kaolin, for example), or from industrial waste (fly ash, blast furnace slag, etc.). Their excellent physicochemical and mechanical properties justify the growing interest they arouse in the construction field. However, their potential of employment remains limited due to the use, during their preparation, of highly concentrated alkaline solutions causing significant health risks and transport storage difficulty; hence it is necessary to implement solvent-free manufacturing techniques.This thesis aims to propose a new producing pre-geopolymer powders (PGP) method by “mechanosynthesis” that are easy to transport and store. Several raw materials, of different types and chemical compositions, were tested as aluminosilicate precursors (fly ash, metakaolin, blast furnace slag and clay); they were activated by different alkaline mixtures (NaOH, KOH, Na2SiO3 and CaO), at fixed mass ratios. The effect of several process parameters was considered, including milling time and speed rotation. The produced pre-geopolymer powders were then incorporated into formulations of pastes, mortars and bituminous mixes. The pastes physicochemical and mechanical properties were studied. The obtained results were compared with those of pastes made by the conventional method under the same conditions. The kinetics of pastes geopolymerization reaction were followed by infrared spectrometry in situ just after the hydration of the PGP. In addition, the indirect mechanosynthesis process has been used to improve the reactivity of clay.The results demonstrated the mechanosynthesis process efficiency for producing the pre-geopolymer powders. These give rise after hydration to geopolymer pastes with a similar structure to that of conventional geopolymers. This process has also helped to improve the mechanical performances of geopolymer products. The pre-geopolymer powders based on illitic clay, produced by indirect mechanosynthesis, give rise to pastes with mechanical resistance reaching 72.5 MPa after 28 curing days at 20 ° C and 50% of relative humidity, against 12.5 MPa for the classic case. The results obtained on slag-based mortars show mechanical strengths reaching 38 MPa after 28 curing daysFinally, the preliminary results on slag PGP-based bituminous mixes reveal better water and rutting resistance, even after 100,000 cycles, than those of the reference formulas without PGP, Les géopolymères sont des matériaux inorganiques fabriqués à partir de composés d’origine naturelle (kaolin, par exemple), ou issus de déchets industriels (cendres volantes, laitiers de hauts fourneaux…). Leurs excellentes propriétés physico-chimiques et mécaniques justifie l’intérêt grandissant qu’ils suscitent dans le domaine de la construction. Toutefois, leur potentiel d’utilisation reste limité en raison de l’emploi, lors de leur préparation, de solutions alcalines fortement concentrées présentant des risques sanitaires importants et d’une difficulté de stockage et transport ; d’où la nécessité d’implémenter des techniques de confection sans solvant. Cette thèse vise à proposer une nouvelle méthode d’élaboration de poudres pré-géopolymères (PGP) par « mécanosynthèse » faciles à transporter et à stocker. Plusieurs matières premières, de différentes natures et compositions chimiques, ont été testées comme précurseurs aluminosilicatés (cendres volantes, métakaolin, laitier de hauts fourneaux et argile) ; elles ont été activées par différents mélanges alcalins (NaOH, KOH, Na2SiO3 et CaO), à des ratios massiques fixés. L’effet de plusieurs paramètres de procédé a été considéré, notamment le temps et la vitesse de broyage. Les poudres pré-géopolymères produites ont été ensuite incorporées dans des formulations de pâtes, de mortiers et d’enrobés bitumineux. Les propriétés physico-chimiques et mécaniques des pâtes produites ont été étudiées. Les résultats obtenus ont été comparés à ceux des pâtes confectionnées par la méthode classique dans les mêmes conditions. La cinétique de la réaction de géopolymérisation des pâtes a été suivie par spectrométrie infrarouge in situ juste après l’hydratation des PGP. Par ailleurs, le procédé de mécanosynthèse indirecte a été utilisé pour améliorer la réactivité de l’argile.Les résultats ont mis en évidence l’efficacité du procédé de mécanosynthèse pour l’élaboration de poudres pré-géopolymères. Celles-ci donnent lieu après hydratation à des pâtes géopolymères avec une structure semblable à celle des géopolymères classiques. Ce procédé a également permis d’améliorer les performances mécaniques des produits géopolymères. Les poudres pré-géopolymères à base d’argile illitique produites par mécanosynthèse indirecte donnent lieu à des pâtes avec une résistance mécanique atteignant 72,5 MPa après 28 jours de cure à 20 °C et 50 % d’humidité relative, contre 12,5 MPa dans le cas classique. Les résultats obtenus sur les mortiers à base de PGP-laitier montrent des résistances mécaniques qui atteignent 38 MPa après 28 jours de cure.Enfin, les résultats préliminaires sur les enrobés bitumineux à base de PGP révèlent une meilleure tenue à l’eau et résistance à l’orniérage, même après 100.000 cycles, que celles des formules de référence sans PGP

International audience; Fourteen dyes based on 2,4,5,7-tetranitrofluorene (TNF) as the electron acceptor have been designed and prepared in a one-step synthesis. By modifying the electron donor, optical properties of the dyes could be efficiently tuned and an absorption ranging between 450 nm and 700 nm could be determined by UV-visible absorption spectroscopy. To get a deeper insight into the optical properties, solvatochromism of the fourteen dyes has also been examined. For all dyes, a positive solvatochromism was determined using different solvent polarity scales such as the Kamlet-Taft and the Catalan empirical scales. Finally, electrochemical properties were also examined, and a comparison of the electrochemical and optical bandgaps could be established. Theoretical calculations were also performed to characterize the different dyes.

International audience; Crystalline gallium (III) sulfide Ga2S3 samples have been prepared by mechanical-alloying instead of usual heating process. A safe, energy-efficient, and fast process of only 4 h of mechanosynthesis led to the formation of polycrystalline Ga2S3 from pure Ga and S as raw materials. X-ray diffraction measurements and Rietveld refinements show that the as-prepared material is a mixture of mainly hexagonal wurtzite-type β-phase (68 ± 5 wt%; space group P63mc (No. 186)) along with some cubic sphalerite-type γ-phase (32 ± 5 wt%; space group F-43m (No. 216)). In situ high-temperature X-ray diffraction measurements show that the monoclinic phase (space group Cc (No. 9)) appears at 450 °C. Scanning electron microscopy analyses reveal that the morphology of the powder is characterized by aggregates of nanometric particles. Their sizes measured by laser diffraction show a median size around 170 nm after 4 h of ball-milling.

Thèse confidentielle jusqu'au 12 novembre 2022; In this thesis, the physicochemical properties of tannin-derived mesoporous carbons were studied and their electrochemical performance as electrodes for supercapacitors (SCs) was evaluated in aqueous and organic electrolytes. The main objective of this study was to develop a fast and easy, and environmentally friendly method for the synthesis of mesoporous carbons. A novel surfactant-water-assisted mechanochemical mesostructuration (SWAMM) one-pot method was developed and optimized to produce ordered and disordered mesoporous carbons (OMCs and DMCs, respectively), only by adjusting the surfactant to water weight ratio. Further physical or chemical activation of both OMCs and DMCs improved the textural properties of the materials that resulted in good SC performance, even at high charging rates, in aqueous and organic electrolytes. The in-depth characterization performed for these new materials has also led to a better understanding of the effect of order and connectivity of the micro-mesoporous structure on the development of textural properties by the different activation processes and, consequently, on the electrochemical performance of the assembled SC.; Dans cette thèse, les propriétés physico-chimiques des carbones mésoporeux dérivés du tanin ont été étudiées et leurs performances électrochimiques en tant qu’électrodes pour des supercondensateurs (SC) ont été évaluées dans des électrolytes aqueux et organiques. L’objectif principal de cette étude était de développer une méthode de synthèse des carbones mésoporeux rapide, facile et respectueuse de l’environnement. Une nouvelle méthode de mésostructuration mécanochimique, assistée par l’interaction de l’eau avec un tensioactif, en une seule étape (SWAMM) a été développée et optimisée. Elle a permis de produire des carbones mésopororeux ordonnés et désordonnés (CMO et CMD, respectivement), uniquement en ajustant le rapport pondéral entre le tensioactif et l’eau. L’activation physique ou chimique des CMO et des CMD a permis d’améliorer les propriétés texturales des matériaux, ce qui a entraîné de bonnes performances des SC, même à des taux de charge élevés, dans des électrolytes aqueux et organiques. La caractérisation approfondie de ces nouveaux matériaux a également permis de mieux comprendre l’effet de l’ordre et de la connectivité de la structure micro-mésoporeuse sur le développement des propriétés texturales par les différents processus d’activation et, par conséquent, sur les performances électrochimiques des SC assemblés.

International audience; The use of ball mills enabled the efficient mechanosynthesis of a variety of N-aryl,N-alkyl imidazolium salts and of corresponding NHC silver(I) complexes. Transmetalation with ruthenium via mechanochemistry allowed the rapid access (from 1.5 min to 1 h) to complexes having a similar structure to Noels-type precatalysts. Evaluation of the complexes in the ring-opening metathesis polymerization of norbornene in different solvent, including nontoxic ones, showed a high catalytic activity for one of them, comparable to that of the Noels catalyst.

The effect of the substitution by 5%, 15%, 30% and 45% of cement in mortars by milled kaolinite has been studied. Milled Kaolinite clay is obtained by using planetary ball mill. The influence on the mechanical performance and on the pozzolanic reactions are discussed. For both CEM I and CEM II formulations, after only 7 days of curing, the compression strength of mortars with 5% of milled kaolinite is comparable to the one of reference mortars for milling times of 3 h and above. For CEM I mortar, the results of the compressive strength show that 15% of kaolinite milled for 9 h allows the best compressive gain for 28 curing days and 90 curing days with 18.5% and 25.6%, respectively. For CEM II mortar, 15% of kaolinite milled for 9 h exhibits the best values of compressive gain for 28 curing days and 90 curing days with 9.8% and 9.7% respectively.

In this study, we have modified slag and fly ashes by mechanosynthesis process carried out by high-energy ball milling using a planetary mill. In order to optimize the milling conditions, we have added process control agent (PCA). This PCA affects powders agglomeration phenomena during milling and impacts the milling time for the final product. We have studied the structure and microstructure of coproducts (fly ashes and slag) obtained by mechanical activation. In addition, we have also tested the mechanical performances of samples prepared with the addition of activated coproducts.

This study is focused to the proposition of new cement manufacturing process. It is widely known that the cement production is responsible for a significant CO2 release each year (approximatively 4 billon ton). So, it is became necessary to find another cement manufacturing process with a minimum CO2 emission. The aim of this work is to manufacture equivalent clinker by indirect mechanosynthesis process. It consists to combine between mechanical activation of the raw materials (mixture of limestone and clay) and heat treatment less than 900 °C. The equivalent clinker obtained by this method shows the presence of the alite (tricalcim silicate) C3S and belite (dicalcium silicate) C2S and Tricalcium aluminate C3A. CO2 emission by this technique is estimated by 0.3 Ton for 1 Ton of equivalent clinker.

International audience

Construction materials are an essential need for humans. After Water, concrete is the most widely used material in the world and cement production is constantly increasing due to the increase in the world population. In 2010, the annual cement production reached 3.3 billion tonnes. An increase of +6.9% was recorded in 2015 for a production that reached 4.6 billion tonnes.Studies conducted on the environmental impact of the clinker manufacturing process have revealed that for a production of one tonne of clinker, a quantity of 0.7 to 0.8 tonnes of CO2 is released into the atmosphere or an annual emission of 2.8 billion tonnes of CO2. These greenhouse gas emissions are responsible for 5% of global emissions. In order to reduce this impact, solutions already proposed such as the use of alternative fuels for clinker manufacture, the partial substitution of cement by industrial co-products or carbon capture and storage.This thesis is part of a desire to reduce the carbon impact in the manufacture of construction materials by introducing the mechanosynthesis process into the production process of clinker and cement as well as geopolymers.The thesis work has been divided into 3 main parts:The first part concerns the mechanosynthesis process optimization by adding process control agents (PCAs). The use of these agents for the grinding of fly ash and blast furnace slag has reduced the milling time to 15 minutes, whereas without PCA, 1 hour milling time is required, or even 3 hours for optimal milling. Cement pastes which we have substituted up to 50% clinker with industrial co-products activated by mechanosynthesis with PCAs (we have used alcohol and water) have shown higher mechanical performance than those prepared with 100% Portland cement.Cement pastes prepared with a substitution of 50% milled slag 15 min + 4% alcohol has shown an improvement in mechanical performance (compression) of + 10%, + 15% and + 40% compared to a reference cement paste for 7, 28 and 90 days respectively.The second part aims to propose a clinkerization process by indirect mechanosynthesis. We have used limestone and clay (traditional products for clinker manufacturing) to produce an equivalent clinker. To achieve our objective, we have used indirect mechanosynthesis, which consists of coupling a mechanical activation with short milling time and a heat treatment not exceeding 900°C. This technique has allowed us to produce the essential compounds of clinker, C3S alite (Ca3SiO5), β-C2S belite (Ca2SiO4) and C3A aluminates.The last part is focused on the direct mechanosynthesis process used for the production of a ready-to-use geopolymer powder only by adding water. This process consists of mixingaluminosilicates such as slag, fly ash or metakaolin with chemical activators by grinding to obtain a final geopolymer product.Geopolymer paste formulations have been made and encouraging results in terms of compressive strength have been obtained., Les matériaux de construction constituent un besoin indispensable pour les êtres humains. Le béton est, après l’eau, le matériau le plus utilisé dans le monde et la production de ciment est en perpétuelle augmentation du fait de l’accroissement de la population mondiale. En 2010 la production annuelle de ciment a atteint les 3,3 milliards de tonnes, une progression de +6,9% a été constatée en 2015 pour une production de ciment qui a atteint 4,6 milliards de tonnes.Des études menées sur l’impact environnemental du procédé de fabrication du clinker ont révélé que pour une production d’une tonne de clinker, une quantité de l’ordre de 0,7 à 0,8 tonne de CO2 est rejetée dans l’atmosphère, soit une émission annuelle de 2,8 milliards de tonnes de CO2. Ces rejets de gaz à effet de serre sont responsables de 5% des émissions mondiales. Afin de réduire cet impact, des solutions ont déjà été proposées telles que l’utilisation de combustibles alternatifs pour la fabrication du clinker, la substitution partielle du ciment par des coproduits industriels ou le captage et stockage du carbone.Cette thèse s’inscrit dans une volonté de réduire l’impact carbone dans la fabrication des matériaux de construction et cela par l’introduction du procédé de mécanosynthèse dans le processus de production du clinker et du ciment ainsi que des géopolymères.Le travail de thèse a été divisé en 3 grandes parties :La première concerne l’optimisation du procédé de mécanosynthèse par l’ajout d’agents de contrôle (process control agents) « PCA ». L’utilisation de ces agents pour le broyage de cendres volantes et de laitiers de hauts fourneaux a permis de réduire la durée du broyage à 15 minutes, alors que sans PCA un broyage de 1h est nécessaire, voire 3h pour un broyage optimal. Les pâtes cimentaires pour lesquelles nous avons substitué jusqu’à 50% de clinker par des coproduits industriels activés par mécanosynthèse avec des PCA (nous avons utilisé de l’alcool et l’eau) ont montré des performances mécaniques supérieures à celles préparées avec 100% de ciment Portland.Les pâtes cimentaires préparées avec une substitution de 50% de laitier broyé 15 min + 4% d’alcool ont montré une amélioration des performances mécaniques (compression) de + 10%, + 15% et + 40% par rapport à une pâte de ciment référence respectivement pour 7, 28 et 90 jours.La deuxième partie vise à proposer un procédé de clinkérisation par mécanosynthèse indirecte. Dans cette partie nous avons utilisé dans un premier temps du calcaire et de l’argile (produits classiques pour la fabrication du clinker) pour la production d’un clinker équivalent. Pour atteindre notre objectif nous avons utilisé la mécanosynthèse indirecte qui consiste à coupler une activation mécanique de courte durée et un traitement thermique ne dépassant pas les 900°C. Cette techniquenous a permis de produire les composés indispensables au clinker, l’alite C3S (Ca3SiO5), la belite β-C2S (Ca2SiO4) et les aluminates C3A.La dernière partie avait pour but d’utiliser le procédé de mécanosynthèse directe pour la production d’une poudre géopolymère prête à l’emploi seulement par addition d’eau. Ce procédé consiste à mélanger des aluminosilicates tels que des laitiers, des cendres volantes ou du métakaolin avec des activateurs chimiques par broyage pour l’obtention d’un produit géopolymère final.Des formulations de pâtes géopolymères ont été faites et des résultats encourageants en termes de résistance à la compression ont été obtenus.

A combination of the excess enthalpy with the fusion entropy of the pure coformer is suggested to be of interest for coformers screening in order to form a multicomponent system with a given API (cocrystal/co-amorphous).

WOS:000446186000054; Photoredox catalysis based on the [Cu(neo)(DPEphos)]BF4 copper complex allowed getting a significant improvement of the polymerization performances (e.g., thick samples, coatings ...) compared to that obtained with other benchmarked photoinitiators in both cationic (CP) and free radical polymerizations (FRP). Nevertheless, as for other copper complexes classically used as photoinitiators in polymer science, the synthesis of these complexes is carried out in a solvent; this fact remains an obstacle to their widespread use because of the cost associated with the use of a solvent and the complex synthesis procedure. In the present study, on the contrary, an outstanding efficient mechanosynthesis of [Cu(neo)(DPEphos)]BF4-purity \textgreater= 95% outranking the previous Cu(I) mechanosynthesis. allowed (i) to divide the synthesis time by 170-fold (as only 5 min is necessary to get the complex), (ii) to lower the environmental impact and cut the synthetic costs as sociated with solvent usage, and (iii) to access a new Cu(I) complex with a counteranion that is impossible to introduce under the traditional chemistry methods (e.g., I-). Reactivities of the mechanosynthesized copper complexes in resins (FRP and CP) confirmed the very high purity of the obtained copper complex by H-1 nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry.

The first use of a new mechanosynthesized copper complex (Cu(acac)(2dppba)) as a initiator for the redox and redox photoactivated polymerization of methacrylates under air is proposed. This paper (i) describes the mechanosynthesis of this complex, (ii) outlines the relative efficiency of the complex for redox polymerization (mechanosynthesized product vs. solvent synthesized product), (iii) follows the polymerization enhancement under a 405 nm light, and (iv) demonstrates the high performance of this complex in near infrared photoactivated redox polymerization where a completely colorless polymer is obtained (unprecedented under NIR irradiations, 785 nm, here). The light activated polymerization exhibit higher conversions, better time controls (activation control) and higher surface conversions than redox polymerization. The mechanosynthesis is well characterized by two solvent-free methods (visual color change and Electron Spin Resonance) and two solvent-based methods (high resolution-electrospray ionization-mass spectrometry (HR-ESI-MS) and UV–vis spectrometry). The involved mechanisms are discussed. Mechanosynthesis of copper complexes opens new perspectives for copper (photo)redox polymerization catalysts as the environmental impact and economical costs of the complex synthesis are significantly reduced. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017

International audience; Elemental powder mixtures of Fe, Co and Sn of initial compositions Fe 50-y/2 Co 50-y/2 Sn y (2≤y≤26) are ball-milled at high-energy. They yield metastable alloys which are predominantly composed of a supersaturated bcc Fe-Co-Sn phase. The amount of tin dissolved in it is at least ~15 at.% in the dynamical conditions of milling which were selected. A recently discovered stannide, CoSn 5 , passed hitherto unobserved in Co–Sn binary phase diagrams. It forms at Co-Sn interfaces at very short milling times, 0.5h, thanks to the high-diffusivity of cobalt in tin. Finally, neutron diffraction and 119 Sn Mössbauer spectroscopy show that metastable B2 ordering develops in as-milled alloys, for y ≤ 26, when they are further annealed at modest temperature, here for 15h at 675K. The tendency to long-range order in ternary Fe-Co-Sn bcc alloys is thus observed in metastable alloys.

International audience; 17 O NMR spectroscopy has been the subject of vivid interest in recent years, because there is increasing evidence that it can provide unique insight into the structure and reactivity of many molecules and materials. However, due to the very poor natural abundance of oxygen-17, 17 O-labelling is generally a prerequisite. This is a real obstacle for most research groups, because of the high cost and/or strong experimental constraints of the most frequently used 17O-labelling schemes. Here, we demonstrate for the first time that mechanosynthesis offers unique opportunities for enriching in 17 O a variety of organic and inorganic precursors of synthetic interest. The protocols are fast, user-friendly, and low-cost, which makes them highly attractive for a broad research community, and their suitability for 17 O solid state NMR applications is demonstrated.

Oleic acid coated iron ferrite-magnetite nanoparticles (Fe 3 O 4 ) have been synthesized via a new combined route, ceramic method and subsequent wet mechanical milling, starting from a stoichiometric mixture of the easily accessible Fe and Fe 2 O 3 precursors. In the first step, the magnetite has been obtained in well crystallised state by heat treatment of precursor's mixture. In the second step, the as obtained magnetite powder has been wet milled in a high energy planetary ball mill using oleic acid as process control agent. Using the same conditions dry milled magnetite samples have been obtained for comparison. The as obtained powders have been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), magnetic measurements M = f(H), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). According to XRD analysis two different processing mechanisms are observed for dry and wet milling modes. The magnetite mean crystallite size is 19 nm according to XRD after 240 min of wet mechanical milling. The High Resolution SEM confirmed that the powder consists in nanoparticles that have particles with the size up to 30 nm. The bond of the oleic acid to the magnetite nanoparticles has been observed by FTIR and DSC investigations. The presence of free and bonded oleic acid is revealed and the free oleic acid can be removed controlled by heat treatment. The magnetisation of the milled samples is lower as compared to the magnetisation of the un-milled sample due to several causes such as disordered structure, finite size effect and powder contamination. A powder contamination with iron occurs during milling and this leads to the formation of a wustite-FeO phase for the dry milled samples. In the case of the wet milled samples, due to an oleic acid layer the FeO phase formation is prevented.

International audience; In view of developing alternatives to classical peptide synthesis strategies that suffer from low efficacy and negative environmental impact, the reactivity of N‐protected α‐amino acids, amino esters, and N‐ethyl‐N′‐(3‐dimethylaminopropyl)carbodiimide was studied under liquid‐assisted grinding (LAG) conditions. The optimal reaction conditions enabled the intensive and environmentally benign mechanosynthesis of a wide range of dipeptides that could be produced up to the multigram scale. The critical influence of the nature of the liquid additive on the course of the reaction was revealed. Combined with solvent‐free tert‐butoxycarbonyl deprotection steps, this approach was applied to the synthesis of tri‐ and tetrapeptides, thus opening the way to the synthesis of much longer peptides.

International audience; A user-friendly and general mechanochemical method was developed to access rarely described NHC (N-heterocyclic carbene) silver(I) complexes featuring N,N-diarylimidazol(idin)ene ligands and noncoordinating tetrafluoroborate or hexafluorophosphate counter anions. Comparison with syntheses in solution clearly demonstrated the superiority of the ball-milling conditions.

Soft magnetic Fe 3 O 4 /Ni 3 Fe composite powder has been synthetized, starting from Fe, Ni and Fe 2 O 3 powders via mechanosynthesis and subsequent annealing. The incipient formation of Fe 3 O 4 is noticed for the sample milled for 2 h. Formation of Ni 3 Fe and Fe 3 O 4 does not occur completely after milling for 10 h and as a consequence the presence of a small amount of unreacted Fe 2 O 3 can be found. Subsequent annealing led to the complete reaction between the precursors. Even for the un-milled homogenized mixture of precursors, a partial formation of Ni 3 Fe and Fe 3 O 4 occurs during annealing. For the milled and annealed samples, the complete formation of the composite Fe 3 O 4 /Ni 3 Fe occurs after 6 h of milling. The DSC measurements and the XRD patterns of the samples subjected to DSC analysis revealed the formation of FeO phase for the starting sample and the samples milled short times (up to 1 h). The complete of the Fe 3 O 4 is noticed upon increasing milling time. The first magnetization curves reveal a two-stage evolution for the milled samples. For milling times up to 3 h, when the Fe 2 O 3 phase is still significant, the value of magnetization has tendency to decrease. Due to the progressive Fe 3 O 4 and Ni 3 Fe formation, the value of magnetization increases for the samples milled for longer durations. The value of magnetization after annealing is larger than the magnetization value of the milled samples as a result of complete formation of ferrite phase.

International audience; Acylation reactions are ubiquitous in the synthesis of natural products and biologically active compounds. Unfortunately,t hese reactions often require the use of large quantities of volatile and/or toxic solvents, either for the reaction,p urification or isolationo ft he products. Herein we describea nd discusst he possibility of completely eliminating the use of organic solventsf or the synthesis, purification and isolation of products resulting from the acylation of aminesa nd other nucleophiles. Thus,u tilisation of N,N'-carbonyldiimidazole(CDI) allowse fficient coupling between carboxylic acids and variousn ucleophiles under solvent-free mechanical agitation, and water-assisted grinding enables both the purification and isolation of pure products. Critical parameters such as the physicals tate and water solubility of the products, milling material, type of agitation (vibratory or planetary) as wella sc ontamination from wear are analysed and discussed. In addition, original organic-solvent-free conditionsa re proposed to overcome the limitations of this approach. Thec alculations of various green metrics are included, highlighting the particularly low environmental impact of this strategy.

α-, β-, and γ-cyclodextrins (CDs) were modified on their secondary face by mechanosynthesis at room temperature using a laboratory-scale ball-mill. Mono-2-tosylated α-, β-, and γ-CDs were obtained in good yield from mixtures of native α-, β-, and γ-CDs, respectively, N-tosylimidazole, and an inorganic base, with each of them being in the solid state. The yields appeared to be dependent upon the nature of the base and the reaction time. A kinetic monitoring by (1)H NMR spectroscopy demonstrated that the highest yields in mono-2-tosyl-CDs were measured using KOH as a base in very short reaction times (up to 65% in 80 s). Mono-(2,3-manno-epoxide) α-, β-, and γ-CDs were subsequently synthesized by ball-milling a mixture of monotosylated α-, β-, and γ-CDs, respectively, and KOH. The characterization of the modified CDs was carried out by X-ray diffraction, mass spectrometry, solid-state NMR, and diffuse reflectance UV-vis (DR UV-vis) spectroscopies. Clues to the supramolecular arrangement of the molecules in the solid state provide information on the reaction mechanism.

International audience; The perovskite structure is one of the most wonderful to exist in nature. It obeys to a quite simple chemical formula, ABX3, in which A and B are metallic cations and X, an anion, usually oxygen. The anion packing is rather compact and leaves interstices for large A and small B cations. The A cation can be mono, di or trivalent, whereas B can be a di, tri, tetra, penta or hexavalent cation. This gives an extraordinary possibility of different combinations and partial or total substitutions, resulting in an incredible large number of compounds. Their physical and chemical properties strongly depend on the nature and oxidation states of cations, on the anionic and cationic stoichiometry, on the crystalline structure and elaboration techniques, etc. In this work, we review the different and most usual crystalline representations of perovskites, from high (cubic) to low (triclinic) symmetries, some well-known preparation methods, insisting for instance, in quite novel and original techniques such as the mechanosynthesis processing. Physical properties are reviewed, emphasizing the electrical (proton, ionic or mixed conductors) and catalytic properties of Mn- and Co-based perovskites; a thorough view on the ferroelectric properties is presented, including piezoelectricity, thermistors or pyroelectric characteristics, just to mention some of them; relaxors, microwave and optical features are also discussed, to end up with magnetism, superconductivity and multiferroïsme. Some materials discussed herein have already accomplished their way but others have promising horizons in both fundamental and applied research. To our knowledge, no much work exists to relate the crystalline nature of the different perovskite-type compounds with their properties and synthesis procedures, in particular with the most recent and newest processes such as the mechanosynthesis approach. Although this is not intended to be a full review of all existing perovskite materials, this report offers a good compilation of the main compounds, their structure and microstructure, processing and relationships between these features

The solid solution [Pb(Yb1/2Nb1/2)O3]1−x-[PbTiO3]xwas synthesized withx≤60%, using several high-temperature techniques as well as room-temperature mechanosynthesis. The high-temperature synthesis reveals a reaction path involving the synthesis first of the end-members before the solid solution. The density and dielectric constant measured on the ceramics prepared from these powders indicate the crucial role of the synthesis technique in the subsequent properties. Mechanosynthesis results in ceramics with higher density and dielectric constant. Identical optimized sintering conditions were then applied to all investigated compositions and the resulting dielectric properties and chemical orders were compared. All polar orders (antiferroelectricity, ferroelectricity, and relaxor behavior) were evidenced. The 1 : 1 chemical order on the B-site of Pb(Yb1/2Nb1/2)O3results in the formation of a double perovskite Pb2YbNbO6, and the superstructures in the X-ray diagrams signing the existence of this order persist up to 30% PbTiO3. The underlying mechanism for substitution of Yb or Nb by Ti is presented.

Mechanosynthesis was used for the obtaining of Fe 3 O 4 /Fe nanocomposite powder starting from Fe 2 O 3 and Fe powders. Up to 120 min of milling, the powder is a composite material of Fe 2 O 3 /Fe. The Fe and Fe 2 O 3 phases react after 120 min of milling leading to the formation of Fe 3 O 4 phase. The amount of Fe 3 O 4 progressively increases upon increasing the milling time up to 600 min. After 600 min of milling, the powder is a nanocomposite material of Fe 3 O 4 /Fe type with a mean crystallites size of 8 nm for Fe 3 O 4 phase and 19 nm for Fe phase. The particles size and specific surface area are changing upon the formation of Fe 2 O 3 /Fe composite and during transformation of this into Fe 3 O 4 /Fe. The Fe 3 O 4 /Fe composite is stable up to a temperature of 540 °C, independent on milling time. The magnetisation decreases in the first stage of milling when the Fe 2 O 3 /Fe composite particles are formed. For further milling, as a result of the Fe 3 O 4 phase formation, the magnetisation increases. The magnetisation increases continuously upon increasing the milling time from 120 up to 600 min as a result of the progressive formation of Fe 3 O 4 . The magnetisation of Fe 3 O 4 /Fe nanocomposite is reduced as compared to the theoretical one due to the presence of a residual Fe 2 O 3 phase and surface defects.

Composite powder of Fe/Fe2O3type was synthesized by mechanical milling using commercially Fe and Fe2O3powders in mass ratio of 35/65. The milling process leads to the powder homogenization, powder activation and formation of some Fe/Fe2O3composite particles. The Fe/Fe2O3composite powder obtained by mechanical milling and the un-milled Fe/Fe2O3mixture were subjected to the reactive sintering procedure in argon atmosphere at 1100 °C for 6 hours. The sintering procedure promotes the reaction of the Fe with the Fe2O3and the result is a sintered composite compact of Fe/Fe3O4/FeO type. The microstructure of the Fe/Fe3O4/FeO sintered composite compacts presents iron clusters in an oxide matrix. A more homogeneous iron clusters size and distribution in oxide matrix is observed in the case of the sintered compact obtained from mechano-activated powder. The X-ray diffraction (XRD), laser particles size analysis (LPSA), optical (OM) and scanning electron (SEM) microscopies techniques were used for the investigations.

International audience; Different milling conditions have been tried to produce nanoparticles of TiB2 to be used as reinforcement in Al matrix composite materials. The milling of TiB2 compounds leads to a decrease of both the crystallite size and the particle size. Moreover, we demonstrate that the use of optimized conditions with a vibratory miller allows - in a short period of time - the direct synthesis of nanoparticles of TiB2 starting from the elemental powders (Ti and B). Then TiB2 reinforced Al composite was fabricated using a simple powder metallurgy process followed by free sintering under controlled atmosphere. The influence of (i) the nanometric TiB2 particles grain size and (ii) their volume fraction on the hardness and Young's modulus, measured from nanoindentation tests, has been analyzed.

Fine ZnO powder with high sulfur capacity was prepared by mechanical alloying of Zn(s) + S(s) followed by an oxidation treatment under air at 700 °C. X-ray diffraction measurements coupled with other characterization techniques enabled us to study the conversion of ZnS into ZnO and vice versa. This ZnO powder was implemented for gas desulfurization. These tests were performed at 400 °C using an experimental setup monitoring the exhaust gas composition for a feed gas mixture N2/H2S with a H2S content of 1000 ppmv. The measured sulfur capacity was equal to 272 mg S/g adsorbent.

The synthesis of supersaturated bcc Fe44Co44Sn12 by mechanical alloying was followed by various techniques. Two stannides, CoSn5 and FeSn2 form first at interfaces. Tetragonal CoSn5, a very recently discovered stannide, is obtained here by a simple method. These stannides then dissolve and the ternary bcc alloy forms with a progressive and simultaneous dissolution of Co and Sn into bcc Fe. (C) 2013 Elsevier B.V. All rights reserved.

In this study, we present the preparation of a bulk material with a composition of 80GeTe2–20Ga2Te3 by combining mechanosynthesis and sintering. This composition cannot be prepared by conventional melt/quenching technique. The progressive evolution of the powder during ball-milling is followed by X-ray Diffraction (XRD) and Differential Scanning Calorimetry analysis. The final powder obtained is highly crystalline, but a glass transition temperature (Tg) is observed, indicating the presence of some amorphous phase remaining, allowing for its efficient sintering. By hot-pressing, a dense bulk material with a fine microstructure and a high electrical conductivity is obtained. The synthesis method described represents a simple and cost-effective way to produce tellurium-based materials of desired dimension with potential applications for optical storage or thermoelectric devices.

International audience; An eco-friendly methodology for preparing carbamate N-protected α-amino acids is described using ball-milling technology. Some β-amino acids were also investigated in this study. This solvent-free methodology gave Boc-, Z-, and Fmoc-N-protected compounds in good to excellent yields with improved environmental impact compared to classical syntheses in solution. Different planetary ball mills were employed. The results are also discussed according to the different process parameters (grinding material, number of balls, rotation speed).

The mechanosynthesis of Fe–Co–Sn ternary alloys from initial powder mixtures of composition (Fe 50− x /2 Co 50− x /2 )Sn x is studied for x ≤ 33 at.%. Disordered nanocrystalline bcc solid solutions are formed in that way up to Sn contents as large as ∼20 at.%. The dissolution of Sn in near-equiatomic bcc Fe–Co is unambiguously proven by X-ray diffraction and 57 Fe and 119 Sn Mossbauer spectroscopy.

Orthorhombic perovskite solid solutions with YMn 1− x Ni x O 3 and YMn 1− x Co x O 3 compositions ( x = 0, 0.05, 0.10, 0.15) have been prepared by mechanosynthesis from a mixture of oxides in a planetary mill. This method allows the use of high-pressure and high-temperature route to be avoided, which is the habitual method to prepare rare-earth manganites with small ionic radius. The high energy supplied by the milling induces the synthesis of the perovskite oxides with a high distortion due to the Jahn–Teller effect. The stability of the structure with temperature is increased with small amounts of Ni proving that the influence of the Jahn–Teller effect is more important than that of the tolerance factor on the stability of the perovskite polymorph. Such stability is not achieved by Co substitution, as this doping is not so efficient in the formation of Mn 4+ , non-Jahn–Teller cations. Magnetic studies were carried out to determine the properties of the materials obtained by this route.

This thesis is devoted to 1) the preparation of magnetic nickel-based alloys in nanocrystalline state 2) the preparation of nanocrystalline compacts 3) the characterization of physical and in particularly soft magnetic properties of the powder and compacts as a functions of their elaboration parameters. The development of soft magnetic alloys has been achieved by dry or wet high energy milling using benzene as process control agent, leading to nanocrystalline materials. The optimum conditions for powder synthesis have been derived for systems Ni3Fe, 79Ni16Fe5Mo and 77Ni14Fe5Cu4Mo and a protocol containing mechanical milling followed by heat treatment is proposed. This protocol has allowed the preparation of powder having crystallite size tunable from 12-30 nm depending on the milling time and chosen milling method. The as obtained particles size could be controlled by choosing the amount of benzene used. The intrinsic properties of powders as microstructural and structural, magnetic and thermal have been analyzed according to the preparations conditions. A combination of (DSC, TG, IR and MS) techniques has allowed us to explain the presence and decomposition of benzene on the milled powders surface. Two methods have been implemented to develop nanocrystalline soft magnetic compact: spark plasma sintering and preparation of composite materials. The optimum conditions for compaction of magnetic powders were determined by varying the compaction pressure, the polymer quantity, the polymerization method, the particle size, etc.. The dynamic physical properties have been investigated up to frequencies of 100 kHz and a maximum induction level of 0.05 and 0.1 T. Typical values of initial relative permeability between 30 and 50 and core losses between 300 and 7000 W/kg (f = 50 kHz and Bmax = 0.1 T) were obtained and have been discussed in terms of compaction parameters. For the spark plasma sintered compacts, maximum relative permeability between 200 and 900 were obtained by varying the sintering temperature and process duration. A post sintering heat treatment (450 °C/4 h) under H2 leads to a decrease in the coercive field of about 50% and increased permeability of up to 600 % conserving the nanocrystalline structure of the compacts. The magnetic properties of the composite compacts were modeled on the basis of the Bruggemann model.; Cette thèse est consacrée à 1) la préparation d'alliages magnétiques base nickel à l'état nanocristallin 2) à l'élaboration de compacts nanocristallins 3) la caractérisation des propriétés physiques et particulièrement magnétiques douces des poudres et des compacts en fonction des paramètres d'élaboration. L'élaboration des alliages magnétiques doux a été réalisée par broyage mécanique de haute énergie à sec ou en utilisant le benzène comme agent de contrôle, conduisant à des matériaux nanocristallins. Les conditions optimales de synthèse des poudres ont été déduites pour les systèmes Ni3Fe, 79Ni16Fe5Mo et 77Ni14Fe5Cu4Mo et un protocole contenant broyage mécanique par voie humide suivi d'un traitement thermique est proposé. Ce protocole a permis de préparer des cristallites de taille ajustable de 12 à 30 nm selon la durée et le mode de broyage choisi. La taille des particules obtenues a pu être contrôlée par le choix de la quantité de benzène utilisée. Les propriétés intrinsèques des poudres tant microstructurales que structurales, magnétiques et thermiques ont été analysées en fonction des conditions d'élaboration. Une combinaison de techniques (DSC, TG, IR et MS) nous a permis d'expliquer la présence et la décomposition de benzène sur la surface des poudres broyées. Deux méthodes ont été mises en oeuvre pour élaborer des compacts nanocristallins magnétiques doux : le frittage plasma et la préparation de matériaux composites. Les conditions optimales de compactage de poudres magnétiques ont été déterminées en variant la pression de compactage, le taux de polymère, la méthode de polymérisation, la taille de particules, etc. Les propriétés physiques dynamiques ont été étudiées jusqu'à des fréquences de 100 kHz et une induction maximale de 0,05 et 0,1 T. Des valeurs typiques de la perméabilité relative initiale comprises entre 30 et 50 et des pertes comprises entre 300 et 7000 W/kg (f = 50 kHz et Bmax = 0,1 T) ont été obtenues et ont été discutées en fonction des paramètres de compactage. Pour les compacts obtenus par frittage plasma, des perméabilités relatives maximales comprises entre 200 et 900 ont été obtenues en variant la température et la durée du processus. Un traitement thermique post frittage (450 °C/4 h) sous H2 conduit à une diminution du champ coercitif d'environ 50 % et une augmentation de la perméabilité de jusqu'à 600 % en conservant la structure nanocristalline de compacts. Les propriétés magnétiques des compacts composites ont été modélisées sur la base du modèle de Bruggemann.

This thesis is devoted to 1) the preparation of magnetic nickel-based alloys in nanocrystalline state 2) the preparation of nanocrystalline compacts 3) the characterization of physical and in particularly soft magnetic properties of the powder and compacts as a functions of their elaboration parameters. The development of soft magnetic alloys has been achieved by dry or wet high energy milling using benzene as process control agent, leading to nanocrystalline materials. The optimum conditions for powder synthesis have been derived for systems Ni3Fe, 79Ni16Fe5Mo and 77Ni14Fe5Cu4Mo and a protocol containing mechanical milling followed by heat treatment is proposed. This protocol has allowed the preparation of powder having crystallite size tunable from 12-30 nm depending on the milling time and chosen milling method. The as obtained particles size could be controlled by choosing the amount of benzene used. The intrinsic properties of powders as microstructural and structural, magnetic and thermal have been analyzed according to the preparations conditions. A combination of (DSC, TG, IR and MS) techniques has allowed us to explain the presence and decomposition of benzene on the milled powders surface. Two methods have been implemented to develop nanocrystalline soft magnetic compact: spark plasma sintering and preparation of composite materials. The optimum conditions for compaction of magnetic powders were determined by varying the compaction pressure, the polymer quantity, the polymerization method, the particle size, etc.. The dynamic physical properties have been investigated up to frequencies of 100 kHz and a maximum induction level of 0.05 and 0.1 T. Typical values of initial relative permeability between 30 and 50 and core losses between 300 and 7000 W/kg (f = 50 kHz and Bmax = 0.1 T) were obtained and have been discussed in terms of compaction parameters. For the spark plasma sintered compacts, maximum relative permeability between 200 and 900 were obtained by varying the sintering temperature and process duration. A post sintering heat treatment (450 °C/4 h) under H2 leads to a decrease in the coercive field of about 50% and increased permeability of up to 600 % conserving the nanocrystalline structure of the compacts. The magnetic properties of the composite compacts were modeled on the basis of the Bruggemann model., Cette thèse est consacrée à 1) la préparation d'alliages magnétiques base nickel à l'état nanocristallin 2) à l'élaboration de compacts nanocristallins 3) la caractérisation des propriétés physiques et particulièrement magnétiques douces des poudres et des compacts en fonction des paramètres d'élaboration. L'élaboration des alliages magnétiques doux a été réalisée par broyage mécanique de haute énergie à sec ou en utilisant le benzène comme agent de contrôle, conduisant à des matériaux nanocristallins. Les conditions optimales de synthèse des poudres ont été déduites pour les systèmes Ni3Fe, 79Ni16Fe5Mo et 77Ni14Fe5Cu4Mo et un protocole contenant broyage mécanique par voie humide suivi d'un traitement thermique est proposé. Ce protocole a permis de préparer des cristallites de taille ajustable de 12 à 30 nm selon la durée et le mode de broyage choisi. La taille des particules obtenues a pu être contrôlée par le choix de la quantité de benzène utilisée. Les propriétés intrinsèques des poudres tant microstructurales que structurales, magnétiques et thermiques ont été analysées en fonction des conditions d'élaboration. Une combinaison de techniques (DSC, TG, IR et MS) nous a permis d'expliquer la présence et la décomposition de benzène sur la surface des poudres broyées. Deux méthodes ont été mises en oeuvre pour élaborer des compacts nanocristallins magnétiques doux : le frittage plasma et la préparation de matériaux composites. Les conditions optimales de compactage de poudres magnétiques ont été déterminées en variant la pression de compactage, le taux de polymère, la méthode de polymérisation, la taille de particules, etc. Les propriétés physiques dynamiques ont été étudiées jusqu'à des fréquences de 100 kHz et une induction maximale de 0,05 et 0,1 T. Des valeurs typiques de la perméabilité relative initiale comprises entre 30 et 50 et des pertes comprises entre 300 et 7000 W/kg (f = 50 kHz et Bmax = 0,1 T) ont été obtenues et ont été discutées en fonction des paramètres de compactage. Pour les compacts obtenus par frittage plasma, des perméabilités relatives maximales comprises entre 200 et 900 ont été obtenues en variant la température et la durée du processus. Un traitement thermique post frittage (450 °C/4 h) sous H2 conduit à une diminution du champ coercitif d'environ 50 % et une augmentation de la perméabilité de jusqu'à 600 % en conservant la structure nanocristalline de compacts. Les propriétés magnétiques des compacts composites ont été modélisées sur la base du modèle de Bruggemann.

International audience; Various C-aryl and C-alkyl-nitrones were synthesized within 0.5-2h via condensation of an equinolear amount of aldehydes and N-substituted-hydroxylamines under solvent free conditions in a ball-mill apparatus. Reactions can be performed without the need of excluding air and moisture and yields the expected products with no need for further purification. The study has been complemented by Differential Scanning Calorimetry (DSC) and solid-state 13C Mass nuclear magnetic resonance experiments. We have also studied the temperature profile during the reaction. A comparative study with the corresponding solvent-free microwave activated reaction showed be superiority of the ball-milling method; 31 examples are described, including the synthesis of the anti-aging agent C-phenyl-N-tert-butyl nitrone (PBN) and one of its analogues C-2-pyridyl-N-tert-butylnitrone (2-PyBN).

This thesis deals with molecular alloys mechanosynthesis obtained by co-milling. The compounds studied are used as excipients in pharmaceutical industry. It concerns lactose, trehalose and mannitol. We show that co-milling of crystalline powders of trehalose/mannitol and of lactose/mannitol generate, for some composition range, homogeneous glass solutions. These studies show, from original way, the influence of milling temperature regard to glass transition temperature (Tg) on the nature of the final states obtained by milling : we have changed the glass transition temperature by changing the chemical composition of molecular alloys. The effect of milling on the pure compounds has also been studied. Ball milling of lactose and trehalose below their Tg induces a direct crystal - > glass transformation. Ball milling above Tg of mannitol ß, stable form, and of mannitol d, the most metastable form, induces a polymorphic transformation towards mannitol a, which is of intermediate stability. These results show that states obtained under ball milling are stationary states rather than thermodynamic equilibrium states. Moreover, our investigations permit to determine some specific properties of the systems studied which are not accessible from liquid states. We have characterised in details mutarotation of lactose. Binary phase diagrams trehalose/mannitol and lactose/mannitol are also proposed. All the results have been obtained by XRD, NMR, DSC and TGA experiments.; Ce mémoire est consacré à la mécanosynthèse d'alliages moléculaires par cobroyage. Les composés étudiés sont des composés utilisés comme excipients dans l'industrie pharmaceutique. Il s'agit plus particulièrement du lactose, du tréhalose et du mannitol. Nos investigations ont montré la possibilité d'obtenir, sur une certaine gamme de concentrations, des solutions solides vitreuses homogènes tréhalose/mannitol et lactose/mannitol par cobroyage des poudres cristallines correspondantes. Elles ont aussi permis de montrer de manière originale l'influence de la position relative de la température de broyage par rapport à la température de transition vitreuse (Tg) sur la nature des états obtenus par broyage en faisant varier la zone de Tg des alliages par changement de composition chimique. Les transformations sous broyage des composés purs ont également été étudiées en détail. Le broyage du lactose et du tréhalose en dessous de Tg est à l'origine d'une transformation directe cristal -> verre à l'état solide. Par contre, le broyage des formes cristallines d et ß? du mannitol au dessus de Tg engendre une transformation polymorphique vers la forme cristalline a de stabilité intermédiaire montrant, de ce fait, le caractère stationnaire des états atteints au cours de ce type de transformations. De plus, nos investigations ont permis de déterminer un certain nombre de propriétés spécifiques de ces systèmes inaccessibles à partir des liquides purs et des mélanges liquides. La mutarotation du lactose a pu être caractérisée en détail. Les diagrammes de phases des mélanges lactose/mannitol et tréhalose/mannitol ont pu être établis. L'ensemble de ces résultats a été obtenu par DRX, RMN, DSC et ATG.

Intermetallic phases Li-Sn were synthesized by ball-milling and characterized for their structures and electrochemical performances. All phases in Li-Sn binary phase diagram were identified by 119Sn Mossbauer spectroscopy, used as reference materials for the study of lithium insertion into tin-based electrode materials. The observed spectra show two distinct environments of tin; the Sn-rich phases and the Li-rich phases. An example of electrochemical properties of these phases is proposed for Li22Sns. Irreversibility of the first cycle is related to the structural change (3D→2D) of this phase.

Not available; Des poudres composites alumine-métal (Fe, Cr, Ni, Nb, V… ) ont été élaborées par mécanosynthèse dans le but de réaliser ultérieurement des matériaux denses et massifs. Ces produits, à grains nanocristallins, sont obtenus par broyage réactif à haute énergie d'un mélange de poudres d'aluminium et d'oxydes métalliques. Un large domaine de composition (de 0 à 36% en volume) de la phase métallique (fer ou chrome) est exploré. Deux voies distinctes de mise en forme et de consolidation ont été suivies (pressage uniaxial à chaud sur poudres sèches et suspensions filtre-pressées). La mise en place progressive de la microstructure lors de la densification des poudres réactives et ayant complètement réagi a été étudiée. Des hypothèses sur les mécanismes qui régissent l'évolution de la microstructure ont été émises. Les propriétés physiques, électriques et mécaniques des différents cermets obtenus ont été mesurées. Le renforcement par différents mécanismes de la matrice d'alumine par la seconde phase métallique est mis en évidence ainsi que l'importance de l'interface dans ces composites et sa possible modification par l'addition d'élément d'addition comme le titane.

Not available, Des poudres composites alumine-métal (Fe, Cr, Ni, Nb, V… ) ont été élaborées par mécanosynthèse dans le but de réaliser ultérieurement des matériaux denses et massifs. Ces produits, à grains nanocristallins, sont obtenus par broyage réactif à haute énergie d'un mélange de poudres d'aluminium et d'oxydes métalliques. Un large domaine de composition (de 0 à 36% en volume) de la phase métallique (fer ou chrome) est exploré. Deux voies distinctes de mise en forme et de consolidation ont été suivies (pressage uniaxial à chaud sur poudres sèches et suspensions filtre-pressées). La mise en place progressive de la microstructure lors de la densification des poudres réactives et ayant complètement réagi a été étudiée. Des hypothèses sur les mécanismes qui régissent l'évolution de la microstructure ont été émises. Les propriétés physiques, électriques et mécaniques des différents cermets obtenus ont été mesurées. Le renforcement par différents mécanismes de la matrice d'alumine par la seconde phase métallique est mis en évidence ainsi que l'importance de l'interface dans ces composites et sa possible modification par l'addition d'élément d'addition comme le titane.