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David Portehault - One of the best experts on this subject based on the ideXlab platform.
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Liquid Phase Synthesis sintering and transport properties of nanoparticle based boron rich composites
Chemistry of Materials, 2021Co-Authors: Guillaume Gouget, Damien Bregiroux, Remi Grosjean, David Montero, Stefan A Maier, Franck Gascoin, Clement Sanchez, David PortehaultAbstract:Nanostructuring boron-rich materials should significantly impact their thermal and electrical transport properties. Nonetheless, nanostructured monoliths of such materials could not be achieved in the 10 nm range so far, because of the large temperatures required to synthesize and produce boron-rich compounds. Such a nanostructuration may have important consequences for achieving a trade-off between enhanced electrical and low thermal conductivity in boron-rich materials, which are among the few materials enabling thermoelectric power generation above 1000 K thanks to their thermal stability, high positive Seebeck coefficients, and low thermal conductivity. In this study, we use a one-pot Synthesis in inorganic molten salts to yield a nanocomposite consisting of metallic HfB2 nanocrystals dispersed in an insulating amorphous boron-rich matrix with a controlled volume fraction of nanocrystals from 16 to 56 vol %. We show that this controlled Liquid-Phase Synthesis can be coupled to spark plasma sintering for densification preserving the nanostructure. The relationships between the reagent ratio in the Liquid-Phase Synthesis, sintering conditions, and transport properties of the densified nanocomposites are then highlighted. We then design materials exhibiting metallic electrical conductivity related to the HfB2 nanocrystals, together with enhanced thermal dissipation attributed to the nanostructured amorphous boron matrix. Combined with the versatility offered by in-solution routes toward boride-based nanocomposites, this work opens a new avenue for tuning transport properties in boron-rich nanomaterials.
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Liquid Phase Synthesis sintering and transport properties of nanoparticle based boron rich composites
Chemistry of Materials, 2021Co-Authors: Guillaume Gouget, Damien Bregiroux, Remi Grosjean, David Montero, Stefan A Maier, Franck Gascoin, Clement Sanchez, David PortehaultAbstract:Nanostructuring boron-rich materials should significantly impact their thermal and electrical transport properties. Nonetheless, nanostructured monoliths of such materials could not be achieved in ...
Andrew G Livingston - One of the best experts on this subject based on the ideXlab platform.
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sequence defined multifunctional polyethers via Liquid Phase Synthesis with molecular sieving
Nature Chemistry, 2019Co-Authors: Ruijiao Dong, Ruiyi Liu, Piers R J Gaffney, Marc Schaepertoens, Patrizia Marchetti, Christopher Williams, Rongjun Chen, Andrew G LivingstonAbstract:Synthetic chemists have devoted tremendous effort towards the production of precision synthetic polymers with defined sequences and specific functions. However, the creation of a general technology that enables precise control over monomer sequence, with efficient isolation of the target polymers, is highly challenging. Here, we report a robust strategy for the production of sequence-defined synthetic polymers through a combination of Liquid-Phase Synthesis and selective molecular sieving. The polymer is assembled in solution with real-time monitoring to ensure couplings proceed to completion, on a three-armed star-shaped macromolecule to maximize efficiency during the molecular sieving process. This approach is applied to the construction of sequence-defined polyethers, with side-arms at precisely defined locations that can undergo site-selective modification after polymerization. Using this versatile strategy, we have introduced structural and functional diversity into sequence-defined polyethers, unlocking their potential for real-life applications in nanotechnology, healthcare and information storage.
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author correction sequence defined multifunctional polyethers via Liquid Phase Synthesis with molecular sieving
Nature Chemistry, 2019Co-Authors: Ruijiao Dong, Ruiyi Liu, Piers R J Gaffney, Marc Schaepertoens, Patrizia Marchetti, Christopher Williams, Rongjun Chen, Andrew G LivingstonAbstract:In the version of this Article originally published, the authors inadvertently cited ref. 10 in two places in the first paragraph. They would like to clarify that it should not have been cited in the sentence that starts “Polymer chemists have employed strategies such as single monomer insertion...” as it mistakenly implied that the IEG+ method described in ref. 10 could not produce unimolecular polymers; it can do so, as was demonstrated in ref. 10. The authors would also like to clarify that ref. 10 should not have been cited in the sentence that starts “Moreover, solid-Phase Synthesis is generally difficult to scale up...", as it implied that ref. 10 uses solid-Phase Synthesis; it does not, and is a purely Liquid-Phase process. The citation of ref. 10 has now been removed from these two sentences, but has been included elsewhere in the first two paragraphs of the Article as follows. In the first paragraph, at the end of the sentence “In iterative Synthesis, specific monomers are added one at a time, or as multiples, to the end of a growing polymer chain, then reaction debris is separated from the chain extended polymer, and the cycle is repeated using the next monomer in the sequence10–12.”; this sentence has been further amended to indicate multiple monomers can also be added. The reference has also been added to the end of the first sentence of the second paragraph, which starts “Consequently, Liquid-Phase iterative synthetic methods...”, and in the third sentence of that paragraph, which now starts “For example, Johnson10, Whiting....”.
Remi Grosjean - One of the best experts on this subject based on the ideXlab platform.
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Liquid Phase Synthesis sintering and transport properties of nanoparticle based boron rich composites
Chemistry of Materials, 2021Co-Authors: Guillaume Gouget, Damien Bregiroux, Remi Grosjean, David Montero, Stefan A Maier, Franck Gascoin, Clement Sanchez, David PortehaultAbstract:Nanostructuring boron-rich materials should significantly impact their thermal and electrical transport properties. Nonetheless, nanostructured monoliths of such materials could not be achieved in the 10 nm range so far, because of the large temperatures required to synthesize and produce boron-rich compounds. Such a nanostructuration may have important consequences for achieving a trade-off between enhanced electrical and low thermal conductivity in boron-rich materials, which are among the few materials enabling thermoelectric power generation above 1000 K thanks to their thermal stability, high positive Seebeck coefficients, and low thermal conductivity. In this study, we use a one-pot Synthesis in inorganic molten salts to yield a nanocomposite consisting of metallic HfB2 nanocrystals dispersed in an insulating amorphous boron-rich matrix with a controlled volume fraction of nanocrystals from 16 to 56 vol %. We show that this controlled Liquid-Phase Synthesis can be coupled to spark plasma sintering for densification preserving the nanostructure. The relationships between the reagent ratio in the Liquid-Phase Synthesis, sintering conditions, and transport properties of the densified nanocomposites are then highlighted. We then design materials exhibiting metallic electrical conductivity related to the HfB2 nanocrystals, together with enhanced thermal dissipation attributed to the nanostructured amorphous boron matrix. Combined with the versatility offered by in-solution routes toward boride-based nanocomposites, this work opens a new avenue for tuning transport properties in boron-rich nanomaterials.
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Liquid Phase Synthesis sintering and transport properties of nanoparticle based boron rich composites
Chemistry of Materials, 2021Co-Authors: Guillaume Gouget, Damien Bregiroux, Remi Grosjean, David Montero, Stefan A Maier, Franck Gascoin, Clement Sanchez, David PortehaultAbstract:Nanostructuring boron-rich materials should significantly impact their thermal and electrical transport properties. Nonetheless, nanostructured monoliths of such materials could not be achieved in ...
Guillaume Gouget - One of the best experts on this subject based on the ideXlab platform.
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Liquid Phase Synthesis sintering and transport properties of nanoparticle based boron rich composites
Chemistry of Materials, 2021Co-Authors: Guillaume Gouget, Damien Bregiroux, Remi Grosjean, David Montero, Stefan A Maier, Franck Gascoin, Clement Sanchez, David PortehaultAbstract:Nanostructuring boron-rich materials should significantly impact their thermal and electrical transport properties. Nonetheless, nanostructured monoliths of such materials could not be achieved in the 10 nm range so far, because of the large temperatures required to synthesize and produce boron-rich compounds. Such a nanostructuration may have important consequences for achieving a trade-off between enhanced electrical and low thermal conductivity in boron-rich materials, which are among the few materials enabling thermoelectric power generation above 1000 K thanks to their thermal stability, high positive Seebeck coefficients, and low thermal conductivity. In this study, we use a one-pot Synthesis in inorganic molten salts to yield a nanocomposite consisting of metallic HfB2 nanocrystals dispersed in an insulating amorphous boron-rich matrix with a controlled volume fraction of nanocrystals from 16 to 56 vol %. We show that this controlled Liquid-Phase Synthesis can be coupled to spark plasma sintering for densification preserving the nanostructure. The relationships between the reagent ratio in the Liquid-Phase Synthesis, sintering conditions, and transport properties of the densified nanocomposites are then highlighted. We then design materials exhibiting metallic electrical conductivity related to the HfB2 nanocrystals, together with enhanced thermal dissipation attributed to the nanostructured amorphous boron matrix. Combined with the versatility offered by in-solution routes toward boride-based nanocomposites, this work opens a new avenue for tuning transport properties in boron-rich nanomaterials.
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Liquid Phase Synthesis sintering and transport properties of nanoparticle based boron rich composites
Chemistry of Materials, 2021Co-Authors: Guillaume Gouget, Damien Bregiroux, Remi Grosjean, David Montero, Stefan A Maier, Franck Gascoin, Clement Sanchez, David PortehaultAbstract:Nanostructuring boron-rich materials should significantly impact their thermal and electrical transport properties. Nonetheless, nanostructured monoliths of such materials could not be achieved in ...
Zhicheng Tan - One of the best experts on this subject based on the ideXlab platform.
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low temperature heat capacities and standard molar enthalpy of formation of ethylenediammonium tetrachlorocobaltate ii chloride h3nch2ch2nh3 2 cocl4 cl2 s
Journal of Chemical & Engineering Data, 2010Co-Authors: Wenyan Dan, Yuxia Kong, Chunling Xin, Zhicheng TanAbstract:A coordination compound, ethylenediammonium tetrachlorocobaltate(II) chloride (H3NCH2CH2NH3)(2)[CoCl4]Cl-2, was synthesized by the method of Liquid Phase Synthesis, in which ethylenediamine, cobalt chloride hexahydrate, and concentrated hydrochloric acid were chosen as the reactants. X-ray crystallography, chemical analysis, and elemental analysis were applied to characterize the structure and composition of the complex. Low-temperature heat capacities of the complex were measured with a precise automated adiabatic calorimeter over the temperature range from (78 to 370) K. A polynomial equation of the heat capacities as a function of temperature was fitted by a least-squares method. Smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature of 298.15 K were calculated and tabulated at intervals of 5 K based on the fitted polynomial equation. A reasonable thermochemical cycle was designed, and the standard molar enthalpies of dissolution of the reactants and products of the Synthesis reaction in the selected solvent were measured by an isoperibol solution-reaction calorimeter. The enthalpy change of the reaction was calculated to be Delta H-r(m)o = (17.612 +/- 0.571) kJ.mol(-1) from the data of the standard molar enthalpies of dissolution. The standard molar enthalpy of formation of the title compund was determined to be Delta H-f(m)o {(NH3CH2CH2NH3)(2)[CoCl4]Cl-2, s} = (1499.54 +/- 2.73) kJ.mol(-1) in accordance with Hess's law.
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low temperature heat capacities and standard molar enthalpy of formation of sodium benzoate c6h5coona s
Thermochimica Acta, 2009Co-Authors: Yuxia Kong, Weiwei Yang, Zhicheng TanAbstract:Abstract Sodium benzoate was synthesized by the method of Liquid Phase Synthesis, in which benzoic acid and anhydrous sodium carbonate were chosen as the reactants. The structure and composition of the compound were characterized by FTIR, chemical analysis, elemental analysis and X-ray powder diffraction techniques. Low temperature heat capacities of the compound were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of the heat capacities as a function of the temperature was fitted by least square method. The smoothed heat capacities and the thermodynamic functions of the compound relative to 298.15 K have been calculated based on the equation. In accordance with Hess law, the standard molar enthalpy of formation of the title compound C6H5COONa (s) was determined to be Δ f H ° m [ C 6 H 5 COONa , s ] = − ( 642.56 ± 0.64 ) kJ mo l − 1 by using an isoperibol solution-reaction calorimeter.