The Experts below are selected from a list of 22833 Experts worldwide ranked by ideXlab platform
Claire Mangeney - One of the best experts on this subject based on the ideXlab platform.
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diazonium Salt Chemistry for the design of nano textured anti icing surfaces
Chemical Communications, 2018Co-Authors: Sarra Gamderouich, Jean Pinson, Philippe Decorse, Yun Luo, Remy Herbaut, Laurent Royon, Claire MangeneyAbstract:Aryl diazonium Salts have emerged as a new generation of robust surface modifiers for a wide range of applications. However, their use for creating anti-icing surfaces has never been investigated so far. We fill this gap by modifying nano-textured copper surfaces with aryl diazonium Salts, bearing low surface energy end groups, leading to efficient anti-icing properties.
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grafting of polymeric platforms on gold by combining the diazonium Salt Chemistry and the photoiniferter method
Polymer, 2015Co-Authors: Randa Ahmad, Aazdine Lamouri, Philippe Decorse, Adrien Mocaer, Sarra Gamderouich, Helene Lecoq, Philippe Brunet, Claire MangeneyAbstract:Abstract The grafting of stable and strongly attached polymeric platforms on gold is a key factor for successful applications in biology, catalysis and sensing. Here, we report on the use of a combination of the iniferter method and the diazonium Salt Chemistry for preparing smart polymeric platforms attached through covalent bonds on gold. For this, bifunctional molecules bearing aryl diazonium coupling agents for anchoring on gold and N , N -diethyldithiocarbamate groups for initiating the growth of polymer chains were used. These two moieties were separated by oligo(ethylene oxide) spacers of various lengths allowing a fine tuning of the hydrophilic properties of the grafted photoinitiator layers. Cross-linked copolymers of methacrylic acid (MAA) and N,N′-methylenebisacrylamide (MBAm) were then grown from the gold surfaces under UV light. The polymer films were characterized in terms of chemical composition and wettability by X-ray photoelectron spectroscopy and contact angle measurements, respectively. The grafting procedure was simple, rapid and effective in producing polymer-grafted Au surfaces at room temperature. The diethyldithiocarbamil groups remaining at the end of the growing tethered chains could then be easily exchanged by a UV-light induced radical-exchange experiment in order to obtain terminal amino moieties able to immobilize citrate-capped gold nanoparticles, through electrostatic interactions. The results obtained in the present work highlight the efficiency of the diazonium Salt Chemistry coupled to the photo-iniferter based surface grafting approach to spontaneously functionalize gold surfaces through covalent bonds. This strategy open new opportunities for the preparation of “smart” hybrid platforms made of pH-responsive polymers and nanoparticle assemblies.
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elaboration of hybrid silica particles using a diazonium Salt Chemistry approach
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013Co-Authors: Nebewia Griffete, Aazdine Lamouri, Philippe Decorse, Randa Ahmad, Houcine Benmehdi, Claire MangeneyAbstract:We demonstrate that the reaction of diazonium Salts with silica particles in basic media can provide reactive surface functionalities which are able: (i) to initiate the growth of polymers and (ii) to immobilize iron oxide nanoparticles at the surface of silica particles. Using this strategy, we synthesized hybrid >silica core@poly(acrylic acid) shell particles and magnetic hybrid materials composed of silica cores surrounded by a dense covalent attachment of magnetic iron oxide nanoparticles and polyethyleneglycol chains. Advantages of this functionalization approach rely not only on the simplicity, rapidity and efficiency of the procedure but also on the formation of strong silica aryl surface bonds, highly suitable for a wide variety of potential applications in colloid and surface science and technology.
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synthesis of highly soluble polymer coated magnetic nanoparticles using a combination of diazonium Salt Chemistry and the iniferter method
RSC Advances, 2012Co-Authors: Nebewia Griffete, Aazdine Lamouri, Frederic Herbst, Nordin Felidj, Souad Ammar, Claire MangeneyAbstract:Polymer-coated magnetic nanoparticles were synthesized using an original and simple chemical strategy combining aryl diazonium Salt Chemistry and the iniferter method. This approach provides individually dispersed, highly soluble and pH-sensitive poly(methacrylic acid)-coated magnetic iron oxide nanoparticles.
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preparation of water soluble magnetic nanocrystals using aryl diazonium Salt Chemistry
Journal of the American Chemical Society, 2011Co-Authors: Nebewia Griffete, Jean Pinson, Frederic Herbst, Souad Ammar, Claire MangeneyAbstract:A novel and facile methodology for the in situ surface functionalization of Fe3O4 nanoparticles is proposed, based on the use of aryl diazonium Salts Chemistry. The grafting reaction involves the formation of diazoates in a basic medium. These species are unstable and dediazonize along a homolytic pathway to give aryl radicals which further react with the Fe3O4 NPs during their formation and stop their growth. Advantages of the present approach rely not only on the simplicity, rapidity, and efficiency of the procedure but also on the formation of strong Fe3O4−aryl surface bonds, highly suitable for further applications.
Thomas Bauer - One of the best experts on this subject based on the ideXlab platform.
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Thermal stability of Solar Salt at 650 °C - A deep dive into molten nitrate Salt Chemistry
2020Co-Authors: Alexander Bonk, Markus Braun, Andrea Hanke, Veronika Anna Sötz, Thomas BauerAbstract:At the last SolarPaces conference we demonstrated that the thermal stability of conventional Solar Salt (60-40wt % NaNO3-KNO3) is substantially increased when the storage system including the gas system is sealed.[4] The operating temperature could therefore successfully be enhanced to 600 °C. During the last months we have investigated the temperature regime above 600 °C to push the thermal stability limit even further, e.g. up to 650 °C. In closed systems all gas species relevant for regeneration of the Salt (mainly O2 and NOx), will accumulate in the gas phase and shift chemical equilibria to the nitrate and nitrite side of Eq (1) and (2) (shown later), respectively. Yet, it remains unclear which ions participate in the decomposition process into oxide ions. In this study we explored the role of the nitrate and nitrite ions in the decomposition reactions at temperatures up to 650 °C to confirm their role in the overall decomposition process and the importance of gas composition.
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With a view to elevated operating temperatures in thermal energy storage - Reaction Chemistry of Solar Salt up to 630°C
Solar Energy Materials and Solar Cells, 2020Co-Authors: Veronika Anna Sötz, Alexander Bonk, Thomas BauerAbstract:Abstract Sensible heat storage is a cost-efficient and scalable technology for energy storage. The state-of-the-art storage systems in concentrating solar power (CSP) plants use the storage material Solar Salt, which is a nitrate Salt mixture. Chemical stability of this Salt material is crucial for lifetime reliance, and for development of the storage technology towards higher temperatures. High temperatures enhance the storage capacity, but also promote decomposition reactions. For instance, harmful gases can evolve, and oxide ions are produced, which aggravate corrosion. Up to now, it is unclear how to describe the Salt Chemistry, and how to quantitatively predict the problematic decomposition products. The experimental method in this study is chosen with regard to the exclusion of mass transport limitations. Thin films of Salt are heated to 560–630 °C. The Salt composition is analyzed by ion chromatography and acid-base titration. The ratio of nitrite to nitrate ions stabilizes, which indicates chemical equilibrium of the nitrite forming reaction. The oxide content increases continuously over time, and is interpreted in terms of a kinetic rate law. A consistent mathematical description of Solar Salt Chemistry at high temperatures (≥560 °C) in contact with air is presented. It includes thermodynamic parameters, in particular the reaction enthalpy of 95 ± 4 kJ⋅mol−1 and entropy of 86 ± 5 J⋅mol−1⋅K−1 for the nitrate-nitrite reaction. The microkinetics of the oxide ion formation are characterized by an activation energy of 42 ± 3 kJ⋅mol−1. The work presented finally contributes to a forecast of material stability at and above 560 °C.
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Impact of Solar Salt aging on corrosion of martensitic and austenitic steel for concentrating solar power plants
Solar Energy Materials and Solar Cells, 2019Co-Authors: Alexander Bonk, Stefanie Kaesche, Markus Braun, Dagmar Rückle, Thomas BauerAbstract:Abstract This work addresses the influence of molten nitrate Salt Chemistry on the corrosion behavior of a martensitic high temperature steel and an austenitic stainless steel. It is one of the first addressing controlled degradation of Solar Salt by controlling the gas atmosphere on top of the melt, thus driving the formation of corrosive ions, mainly oxide ions but also nitrite ions. The stainless steel and high temperature steel samples are subjected to the different operating conditions to demonstrate the variations in corrosivity as a function of gas atmosphere and additionally of artificially added chloride impurities. The results indicate that the atmosphere has a direct impact on the formation of corrosive oxide and nitrite ions. The low Cr-steel is found to be more sensitive to chloride impurities, while the stainless steel corrosion is enhanced by the presence of nitrites and oxide ions. All studies are supported by profound molten Salt analysis throughout the experiments including the analysis of nitrate, nitrite, oxide and chromate ions as well as cation compositions. Steel samples are analyzed by scanning electron microscopy methods and corrosion rates are extrapolated from 1200 h experiments.
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influence of different atmospheres on molten Salt Chemistry and its effect on steel corrosion
SolarPACES 2017: International Conference on Concentrating Solar Power and Chemical Energy Systems, 2018Co-Authors: Alexander Bonk, Stefanie Kaesche, Markus Braun, Andrea Hanke, Veronika Anna Sötz, Dagmar Rückle, Jochen Forstner, Thomas BauerAbstract:Dispatchability of renewable solar energy can be realized by integrating thermal energy storage units. In concentrating solar power plants the use of sensible heat storage based on molten nitrate Salts, typically Solar Salt (Na,K//NO3), has proven most beneficial in the last decade. However, a crucial parameter that affects the long-term performance of the TES unit however, is the sustainability and reliability which is directly linked to the material performance of the molten Salt and the construction material. Metallic corrosion is one of the biggest concerns due to the harsh conditions provided by the redox active molten nitrate Salts. The mechanisms of corrosion are thought to be well understood which is reflected by a significant number of publications in the last decades. Despite, an essential parameter is often ignored or underestimated in many studies – the molten Salt Chemistry. This work is one of the first addressing directed degradation of Solar Salt by controlling the gas atmosphere in the storage system, thus driving the formation of corrosive impurities, especially oxide species. Austenitic, stainless Cr,Ni-steel and ferritic Cr-steel samples are subjected to the different operating conditions to demonstrate the variations in corrosivity as a function of gas atmosphere and additionally of artificially added chloride impurities. The experimental matrix allows for a comprehensive analysis of the influence of different corrosive species on the stability of different steel types over the course of 1.200h experiments performed at 560 °C.
Zaiping Guo - One of the best experts on this subject based on the ideXlab platform.
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constructing ultrastable electrode electrolyte interface for rapid potassium ion storage capability via Salt Chemistry and interfacial engineering
Nano Research, 2021Co-Authors: Sheng Wen, Wenchao Zhang, Zaiping Guo, Xiangwei Ding, Li Zhang, Pengcheng Dai, Dandan Liu, Xuebo ZhaoAbstract:Conversion/alloying anode materials exhibiting high K storage capacities suffer from large volume variations and unstable electrode/electrolyte interfaces upon cycling. Herein, taking SnS/reduced graphene oxide (SnS/rGO) anodes as an example, the electrochemical performance of SnS/rGO could significantly be improved via employing potassium bis(fluorosulfonyl)imide (KFSI) Salt in electrolytes and ultrathin TiO2 coating. KF-rich inorganic layer was demonstrated to help form robust SEI layer, which could suppress the side reactions to increase the Coulombic efficiency. The formed potassiated KxTiO2 coating layer was constructed to boost charge transfer capability and K-ion diffusion kinetics. The as-prepared SnS/rGO@TiO2-20 electrode in KFSI electrolyte delivers the high CE of 99.1% and 424 mAh·g−1 after 200 cycles with an ultrahigh capacity retention of 98.5%.
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unraveling the effect of Salt Chemistry on long durability high phosphorus concentration anode for potassium ion batteries
Nano Energy, 2018Co-Authors: Wenchao Zhang, Jian Zhang, Guoping Liu, Naihsuan Yang, R S Liu, Wei Kong Pang, Zaiping GuoAbstract:Abstract Phosphorus-based anode materials are of considerable interest for grid-scale energy storage systems due to their high theoretical capacity. Nevertheless, the low electrical conductivity of P, large volume changes during cycling, and highly-reactive phosphide surface are hindering their potential applications. Herein, outstanding long-term cycling stability with high retained potassium storage capacity (213.7 mA h g−1 over 2000 cycles) was achieved via the introduction of an alternative potassium bis(fluorosulfonyl)imide (KFSI) Salt and by using a layered compound (GeP5) with a high phosphorus concentration as anode material. Fourier transform infrared spectroscopic mapping results suggest that KFSI Salt helps to form an uniform solid electrolyte interphase (SEI) layer and reduces the side reactions at the electrode/electrolyte interface, thus enhancing the cycling performance. In-operando synchrotron X-ray diffraction analysis has revealed the synergistic reaction mechanisms of the K-P and K-Ge reactions. These findings indicate the enormous potential of phosphorus-based anodes for high-performance potassium ion batteries and can attract broad interest for regulating the SEI layer formation through manipulating the Salt Chemistry.
Aazdine Lamouri - One of the best experts on this subject based on the ideXlab platform.
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the molecular and macromolecular level of carbon nanotube modification via diazonium Chemistry emphasis on the 2010s years
Chemistry Africa, 2020Co-Authors: Asma Bensghaier, Aazdine Lamouri, Fatima Mousli, Pavel S Postnikov, Mohamed M ChehimiAbstract:The present review focusses on the recent progress in the reductive grafting of diazotized big molecules and polymers on carbon nanotubes (CNTs). We briefly summarize the essentials on diazonium synthesis and discuss the CNT physical properties. The different routes for CNT covalent functionalization through diazonium Salt interface Chemistry are reviewed. The main analytical and spectroscopic techniques used to track carbon nanotube surface modification were cited as well as their advantages and limitations in the light of the information they provide. In this review, the emphasis is on big molecules such as dyes, crown ether, calixarene, cyclodextrin, fullerene and Ru-complex, and biomolecules such as biotin, proteins, and antibodies. The attachment of synthetic polymers to CNT via diazonium Chemistry, or by preparing CNT-Polymer nanocomposites through: (1) in situ polymerization (controlled radical polymerization and click Chemistry). (2) Oxidative polymerization of conjugated monomers. (3) Grafting onto method by Huisgen 1,3-cycloaddition click reaction and epoxy ring-opening were summarized and discussed. Throughout this review, we reported the recent advances using diazonium Salt Chemistry in numerous research areas (biomedicine, environment, energy conversion, sensors and actuators, structural composites,…).
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grafting of polymeric platforms on gold by combining the diazonium Salt Chemistry and the photoiniferter method
Polymer, 2015Co-Authors: Randa Ahmad, Aazdine Lamouri, Philippe Decorse, Adrien Mocaer, Sarra Gamderouich, Helene Lecoq, Philippe Brunet, Claire MangeneyAbstract:Abstract The grafting of stable and strongly attached polymeric platforms on gold is a key factor for successful applications in biology, catalysis and sensing. Here, we report on the use of a combination of the iniferter method and the diazonium Salt Chemistry for preparing smart polymeric platforms attached through covalent bonds on gold. For this, bifunctional molecules bearing aryl diazonium coupling agents for anchoring on gold and N , N -diethyldithiocarbamate groups for initiating the growth of polymer chains were used. These two moieties were separated by oligo(ethylene oxide) spacers of various lengths allowing a fine tuning of the hydrophilic properties of the grafted photoinitiator layers. Cross-linked copolymers of methacrylic acid (MAA) and N,N′-methylenebisacrylamide (MBAm) were then grown from the gold surfaces under UV light. The polymer films were characterized in terms of chemical composition and wettability by X-ray photoelectron spectroscopy and contact angle measurements, respectively. The grafting procedure was simple, rapid and effective in producing polymer-grafted Au surfaces at room temperature. The diethyldithiocarbamil groups remaining at the end of the growing tethered chains could then be easily exchanged by a UV-light induced radical-exchange experiment in order to obtain terminal amino moieties able to immobilize citrate-capped gold nanoparticles, through electrostatic interactions. The results obtained in the present work highlight the efficiency of the diazonium Salt Chemistry coupled to the photo-iniferter based surface grafting approach to spontaneously functionalize gold surfaces through covalent bonds. This strategy open new opportunities for the preparation of “smart” hybrid platforms made of pH-responsive polymers and nanoparticle assemblies.
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elaboration of hybrid silica particles using a diazonium Salt Chemistry approach
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013Co-Authors: Nebewia Griffete, Aazdine Lamouri, Philippe Decorse, Randa Ahmad, Houcine Benmehdi, Claire MangeneyAbstract:We demonstrate that the reaction of diazonium Salts with silica particles in basic media can provide reactive surface functionalities which are able: (i) to initiate the growth of polymers and (ii) to immobilize iron oxide nanoparticles at the surface of silica particles. Using this strategy, we synthesized hybrid >silica core@poly(acrylic acid) shell particles and magnetic hybrid materials composed of silica cores surrounded by a dense covalent attachment of magnetic iron oxide nanoparticles and polyethyleneglycol chains. Advantages of this functionalization approach rely not only on the simplicity, rapidity and efficiency of the procedure but also on the formation of strong silica aryl surface bonds, highly suitable for a wide variety of potential applications in colloid and surface science and technology.
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Functionalization of Aluminum Nanoparticles Using a Combination of Aryl Diazonium Salt Chemistry and Iniferter Method
The Journal of Physical Chemistry C, 2013Co-Authors: Yasmine Aït Atmane, L. Sicard, Aazdine Lamouri, Jean Pinson, Mickaël Sicard, Christian Masson, Sophie Nowak, Philippe Decorse, Jean-yves Piquemal, Anouk GaltayriesAbstract:In this work, we propose an original strategy for the functionalization of aluminum nanoparticles (Al NPs), based on a combination of aryl diazonium Salt Chemistry and the photopolymerization iniferter method. It consists in grafting coupling agents, derived from diazonium Salts, at the surface of Al NPs and in initiating the photopolymerization of methacrylic acid (MAA) directly from the surface. The hybrid NPs were fully characterized using XRD, TEM, TGA, and XPS. The results show that the obtained hybrids exhibit a core-double shell structure, the metallic core being preserved while a thin natural oxide layer and a strongly anchored organic shell surround it. The controlled and living character of the photopolymerization process allowed for the control of the polymer shell thickness with the polymerization time. Interestingly, the formation of compact aryl layers derived from the diazonium Salts at the surface of Al NPs appears to provide an efficient protection against oxidation.
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synthesis of highly soluble polymer coated magnetic nanoparticles using a combination of diazonium Salt Chemistry and the iniferter method
RSC Advances, 2012Co-Authors: Nebewia Griffete, Aazdine Lamouri, Frederic Herbst, Nordin Felidj, Souad Ammar, Claire MangeneyAbstract:Polymer-coated magnetic nanoparticles were synthesized using an original and simple chemical strategy combining aryl diazonium Salt Chemistry and the iniferter method. This approach provides individually dispersed, highly soluble and pH-sensitive poly(methacrylic acid)-coated magnetic iron oxide nanoparticles.
Nebewia Griffete - One of the best experts on this subject based on the ideXlab platform.
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elaboration of hybrid silica particles using a diazonium Salt Chemistry approach
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013Co-Authors: Nebewia Griffete, Aazdine Lamouri, Philippe Decorse, Randa Ahmad, Houcine Benmehdi, Claire MangeneyAbstract:We demonstrate that the reaction of diazonium Salts with silica particles in basic media can provide reactive surface functionalities which are able: (i) to initiate the growth of polymers and (ii) to immobilize iron oxide nanoparticles at the surface of silica particles. Using this strategy, we synthesized hybrid >silica core@poly(acrylic acid) shell particles and magnetic hybrid materials composed of silica cores surrounded by a dense covalent attachment of magnetic iron oxide nanoparticles and polyethyleneglycol chains. Advantages of this functionalization approach rely not only on the simplicity, rapidity and efficiency of the procedure but also on the formation of strong silica aryl surface bonds, highly suitable for a wide variety of potential applications in colloid and surface science and technology.
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synthesis of highly soluble polymer coated magnetic nanoparticles using a combination of diazonium Salt Chemistry and the iniferter method
RSC Advances, 2012Co-Authors: Nebewia Griffete, Aazdine Lamouri, Frederic Herbst, Nordin Felidj, Souad Ammar, Claire MangeneyAbstract:Polymer-coated magnetic nanoparticles were synthesized using an original and simple chemical strategy combining aryl diazonium Salt Chemistry and the iniferter method. This approach provides individually dispersed, highly soluble and pH-sensitive poly(methacrylic acid)-coated magnetic iron oxide nanoparticles.
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preparation of water soluble magnetic nanocrystals using aryl diazonium Salt Chemistry
Journal of the American Chemical Society, 2011Co-Authors: Nebewia Griffete, Jean Pinson, Frederic Herbst, Souad Ammar, Claire MangeneyAbstract:A novel and facile methodology for the in situ surface functionalization of Fe3O4 nanoparticles is proposed, based on the use of aryl diazonium Salts Chemistry. The grafting reaction involves the formation of diazoates in a basic medium. These species are unstable and dediazonize along a homolytic pathway to give aryl radicals which further react with the Fe3O4 NPs during their formation and stop their growth. Advantages of the present approach rely not only on the simplicity, rapidity, and efficiency of the procedure but also on the formation of strong Fe3O4−aryl surface bonds, highly suitable for further applications.
