Formation at 300°C of a high-temperature disilicate from hydrated lutetium in a layered aluminosilicate

AbstractThe interaction between interlamellar Lu(III) cations and the layered silicate structure has been studied by means of MAS-NMR, XRD and EDX. Irreversible fixation of exchangeable Lu(III) cations upon hydrothermal treatment at 300°C of Lu-saturated montmorillonite is reported, through the formation of the crystalline phase Lu2Si2O7. It is shown that the lowest temperature previously described for this reaction, 400°C, does not indicate a thermodynamic boundary. This basic solid-state finding is relevant for some clay applications such as those related to the safety of nuclear waste repositories with engineering barriers.

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Identification of the high-melting crystalline phase in high-temperature crystalline by solid-state NMR spectroscopy

Macromolecules ◽

10.1021/ma00074a043 ◽

1993 ◽

Vol 26 (22) ◽

pp. 6138-6140 ◽

Cited By ~ 2

Author(s):

A. Bunn ◽

N. J. Clayden ◽

D. J. Kemmish

Keyword(s):

High Temperature ◽

Solid State ◽

Nmr Spectroscopy ◽

Crystalline Phase ◽

Solid State Nmr ◽

High Melting ◽

Solid State Nmr Spectroscopy

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Uranium carbonate complexes demonstrate drastic decrease in stability at elevated temperatures

Communications Chemistry ◽

10.1038/s42004-021-00558-3 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Alexander Kalintsev ◽

Artas Migdisov ◽

Christopher Alcorn ◽

Jason Baker ◽

Joël Brugger ◽

...

Keyword(s):

High Temperature ◽

Nuclear Waste ◽

Nuclear Power ◽

Elevated Temperatures ◽

Ore Deposits ◽

Ambient Conditions ◽

Uranium Ore ◽

Quantitative Understanding ◽

Waste Repositories ◽

Inorganic Ligands

AbstractQuantitative understanding of uranium transport by high temperature fluids is crucial for confident assessment of its migration in a number of natural and artificially induced contexts, such as hydrothermal uranium ore deposits and nuclear waste stored in geological repositories. An additional recent and atypical context would be the seawater inundated fuel of the Fukushima Daiichi Nuclear Power Plant. Given its wide applicability, understanding uranium transport will be useful regardless of whether nuclear power finds increased or decreased adoption in the future. The amount of uranium that can be carried by geofluids is enhanced by the formation of complexes with inorganic ligands. Carbonate has long been touted as a critical transporting ligand for uranium in both ore deposit and waste repository contexts. However, this paradigm has only been supported by experiments conducted at ambient conditions. We have experimentally evaluated the ability of carbonate-bearing fluids to dissolve (and therefore transport) uranium at high temperature, and discovered that in fact, at temperatures above 100 °C, carbonate becomes almost completely irrelevant as a transporting ligand. This demands a re-evaluation of a number of hydrothermal uranium transport models, as carbonate can no longer be considered key to the formation of uranium ore deposits or as an enabler of uranium transport from nuclear waste repositories at elevated temperatures.

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The Nature of Chemisorbed CO2 in Zeolite A

10.26434/chemrxiv.7422815 ◽

2019 ◽

Author(s):

Przemyslaw Rzepka ◽

Zoltán Bacsik ◽

Andrew J. Pell ◽

Niklas Hedin ◽

Aleksander Jaworski

Keyword(s):

Solid State ◽

Ir Spectroscopy ◽

Quantum Chemical Calculations ◽

Quantum Chemical ◽

Surface Coverage ◽

Gas Mixtures ◽

Mas Nmr ◽

Significant Fraction ◽

Zeolite A

Formation of CO32- and HCO3- species without participation of the framework oxygen atoms upon chemisorption of CO2 in zeolite |Na12|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H2O or acid groups. A combined study by solid-state 13C MAS NMR, quantum chemical calculations, and in situ IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO3-. However, at a low surface coverage of physisorbed and acidic CO2, a significant fraction of the HCO3- was deprotonated and transformed into CO32-. We expect that similar chemisorption of CO2 would occur for low-silica zeolites and other basic silicates of interest for the capture of CO2 from gas mixtures.

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Solid-state reaction of niobium with diamond carbon at high pressure and high temperature to form superconducting composite

Mendeleev Communications ◽

10.1016/j.mencom.2021.04.044 ◽

2021 ◽

Vol 31 (3) ◽

pp. 415-418

Author(s):

Vladimir Yu. Osipov ◽

Fedor M. Shakhov ◽

Nikolai M. Romanov ◽

Kazuyuki Takai

Keyword(s):

High Pressure ◽

High Temperature ◽

Solid State ◽

Solid State Reaction

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Changes of Selected Structural and Mechanical Properties of the Strzelin Granites As Induced By Thermal Loads / Wpływ Obciążeń Termicznych Na Zmiany Niektórych Strukturalnych I Mechanicznych Właściwości Granitów Strzelińskich

Archives of Mining Sciences ◽

10.2478/v10267-012-0064-8 ◽

2012 ◽

Vol 57 (4) ◽

pp. 951-974 ◽

Cited By ~ 1

Author(s):

Andrzej Nowakowski ◽

Mariusz Młynarczuk

Keyword(s):

Mechanical Properties ◽

Nuclear Waste ◽

Structural Changes ◽

Structural Parameters ◽

Total Porosity ◽

Fracture Network ◽

Qualitative Description ◽

Temperature Changes ◽

Heating And Cooling ◽

Waste Repositories

Abstract Temperature is one of the basic factors influencing physical and structural properties of rocks. A quantitative and qualitative description of this influence becomes essential in underground construction and, in particular, in the construction of various underground storage facilities, including nuclear waste repositories. The present paper discusses the effects of temperature changes on selected mechanical and structural parameters of the Strzelin granites. Its authors focused on analyzing the changes of granite properties that accompany rapid temperature changes, for temperatures lower than 573ºC, which is the value at which the β - α phase transition in quartz occurs. Some of the criteria for selecting the temperature range were the results of measurements carried out at nuclear waste repositories. It was demonstrated that, as a result of the adopted procedure of heating and cooling of samples, the examined rock starts to reveal measurable structural changes, which, in turn, induces vital changes of its selected mechanical properties. In particular, it was shown that one of the quantities describing the structure of the rock - namely, the fracture network - grew significantly. As a consequence, vital changes could be observed in the following physical quantities characterizing the rock: primary wave velocity (vp), permeability coefficient (k), total porosity (n) and fracture porosity (η), limit of compressive strength (Rσ1) and the accompanying deformation (Rε1), Young’s modulus (E), and Poisson’s ratio (ν).

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A safeguarding and high temperature tolerant organogel electrolyte for flexible solid-state supercapacitors

Journal of Power Sources ◽

10.1016/j.jpowsour.2021.230083 ◽

2021 ◽

Vol 505 ◽

pp. 230083

Author(s):

Yuxuan Wu ◽

Sheng Wang ◽

Min Sang ◽

Quan Shu ◽

Junshuo Zhang ◽

...

Keyword(s):

High Temperature ◽

Solid State

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Combination of solid state NMR and DFT calculation to elucidate the state of sodium in hard carbon electrodes

Journal of Materials Chemistry A ◽

10.1039/c6ta04273b ◽

2016 ◽

Vol 4 (34) ◽

pp. 13183-13193 ◽

Cited By ~ 31

Author(s):

Ryohei Morita ◽

Kazuma Gotoh ◽

Mika Fukunishi ◽

Kei Kubota ◽

Shinichi Komaba ◽

...

Keyword(s):

Solid State ◽

Solid State Nmr ◽

Dft Calculation ◽

Magic Angle Spinning ◽

The State ◽

Mas Nmr ◽

Magic Angle ◽

Multiple Quantum ◽

Hard Carbon ◽

Angle Spinning

We examined the state of sodium electrochemically inserted in HC prepared at 700–2000 °C using solid state Na magic angle spinning (MAS) NMR and multiple quantum (MQ) MAS NMR.

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HKUST-1@IL-Li Solid-state Electrolyte with 3D Ionic Channels and Enhanced Fast Li+ Transport for Lithium Metal Batteries at High Temperature

Nanomaterials ◽

10.3390/nano11030736 ◽

2021 ◽

Vol 11 (3) ◽

pp. 736

Author(s):

Man Li ◽

Tao Chen ◽

Seunghyun Song ◽

Yang Li ◽

Joonho Bae

Keyword(s):

High Temperature ◽

Solid State ◽

Solid Electrolyte ◽

Metal Organic Framework ◽

Ionic Channels ◽

Transference Numbers ◽

Lithium Metal ◽

Lithium Metal Batteries ◽

Metal Organic ◽

Organic Framework

The challenge of safety problems in lithium batteries caused by conventional electrolytes at high temperatures is addressed in this study. A novel solid electrolyte (HKUST-1@IL-Li) was fabricated by immobilizing ionic liquid ([EMIM][TFSI]) in the nanopores of a HKUST-1 metal–organic framework. 3D angstrom-level ionic channels of the metal–organic framework (MOF) host were used to restrict electrolyte anions and acted as “highways” for fast Li+ transport. In addition, lower interfacial resistance between HKUST-1@IL-Li and electrodes was achieved by a wetted contact through open tunnels at the atomic scale. Excellent high thermal stability up to 300 °C and electrochemical properties are observed, including ionic conductivities and Li+ transference numbers of 0.68 × 10-4 S·cm-1 and 0.46, respectively, at 25 °C, and 6.85 × 10-4 S·cm-1 and 0.68, respectively, at 100 °C. A stable Li metal plating/stripping process was observed at 100 °C, suggesting an effectively suppressed growth of Li dendrites. The as-fabricated LiFePO4/HKUST-1@IL-Li/Li solid-state battery exhibits remarkable performance at high temperature with an initial discharge capacity of 144 mAh g-1 at 0.5 C and a high capacity retention of 92% after 100 cycles. Thus, the solid electrolyte in this study demonstrates promising applicability in lithium metal batteries with high performance under extreme thermal environmental conditions.

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