Structural analysis of mixed alkali borosilicate glasses containing Cs<sup>+</sup> and Na<sup>+</sup> using strong magnetic field magic angle spinning nuclear magnetic resonance

Kaneko, Shunichi; Tokuda, Yomei; Takahashi, Yusuke; Masai, Hirokazu; Ueda, Yoshikatsu

doi:10.1016/j.jascer.2016.11.001

Cited by 14 publications

(6 citation statements)

References 26 publications

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“…The structure of mixed-cation silicate glasses has been investigated using classical molecular dynamics (MD) simulations ,, and a wide range of experimental techniques, including solid-state nuclear magnetic resonance (NMR), ,− element-specific synchrotron X-ray spectroscopy, and X-ray or neutron scattering. − 17 O NMR yields specific information about the degree of cation disorder by probing the proportions of NBO and bridging oxygens (BOs), revealing the relationship between the field strength of cations [charge/(radius) 2 ] and the degree of disorder in mixed-cation silicate glasses at 1 atm (see Table in ref ). For instance, cation pairs with the same charges or with smaller differences in cation radii tend to be distributed randomly in silicate glasses, such as Na–K, Ca–Mg, and Ca–Ba .…”

Section: Introductionmentioning

confidence: 99%

Pressure-Induced Structural Transitions in Na–Li Silicate Glasses under Compression

Kim

Lee

2019

J. Phys. Chem. C

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The atomic structures of alkali silicate glasses with more than two types of nonframework cations (e.g., Li and Na) at high pressure provide insights into the effects of pressure on the transport properties of technologically important complex oxide glasses and multicomponent silicate melts in the Earth interiors. Despite the importance, the pressure-induced changes in the atomic structures of Na−Li silicate glasses at high pressure have not been studied. Here, we investigated the effects of pressure on the coordination environments around Si and O and the degree of mixing among alkali cations in amorphous Li−Na silicates quenched from melts at high pressure up to 8 GPa using 7 Li, 17 O, and 29 Si NMR spectroscopy. The proportions of [5,6] Si increase with increasing pressure and tend to decrease with increasing X Li [=Li/(Li + Na)], confirming that an increase in X Li could prohibit the formation of [5,6] Si species in mixed-alkali silicate glasses. 7 Li magic angle spinning NMR results reveal a pressureinduced increase in the Li coordination number and shortening in Li−Li distance stemming from reduction in free volume and the changes in the degree of cation mixing. The 17 O NMR spectra confirmed that the fraction of nonbridging oxygen (NBO) [i.e., (Na,Li)−O− [4] Si] decreases as pressure increases. The decrease in NBO is more prevalent in Li-poor glass, indicating that the degree of network polymerization at high pressure depends on the Li−Na ratio. While the threshold of the difference between ionic radii in chemical order has been suggested to be ∼0.3 Å at 1 atm, chemical order among network modifiers may emerge with ionic radii difference smaller than 0.3 Å at high pressure. Our NMR results indicate that decreasing numbers of similar pairs as pressure increases tend to decrease the diffusivity of Li within Na−Li trisilicate glasses.

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Section: Introductionmentioning

confidence: 99%

Pressure-Induced Structural Transitions in Na–Li Silicate Glasses under Compression

Kim

Lee

2019

J. Phys. Chem. C

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“…In mixed alkali glasses (e.g., Na-K or Na-Cs silicate glasses), physical properties such as the electrical conductivity, molar volume, glass transition temperature, and thermal expansion coefficient can be nonlinear due to the mixed alkali effect (MAE) [83,84]. e MAE has attracted much attention because it is very important for developing unique glass materials with a controllable electrical conductivity or thermal expansion coefficient, respectively [19,85]. Kaneko et al [19] prepared borosilicate (Si : B � 1 : 1) and Si-rich borosilicate (Si : B � 2 : 1) glasses containing alkali cations Cs + and Na+ to study the MAE on nuclides solidification.…”

Section: Simulated 137 Cs In the Immobilization Methods By Usingmentioning

confidence: 99%

“…e MAE has attracted much attention because it is very important for developing unique glass materials with a controllable electrical conductivity or thermal expansion coefficient, respectively [19,85]. Kaneko et al [19] prepared borosilicate (Si : B � 1 : 1) and Si-rich borosilicate (Si : B � 2 : 1) glasses containing alkali cations Cs + and Na+ to study the MAE on nuclides solidification. In the preparation process of the glass samples, chemically pure Cs 2 CO 3 together with SiO 2 , B(OH) 3 , and Na 2 CO 3 were used to prepare the glass samples by the melting method (temperatures of 1350°C, 1100°C, and 1350°C for silicate, borate, and borosilicate glasses, resp.…”

Section: Simulated 137 Cs In the Immobilization Methods By Usingmentioning

confidence: 99%

“…e main purposes of these studies are summarized as developing new solidifying materials, increasing the loading of radioactive waste, reducing the leaching of radionuclides, enhancing the mechanical strength of solidified bodies, and reducing the disposal difficulty and cost. Additionally, computer simulation methods [13,[19][20][21][22][23], such as quantum mechanical and empirical models of atomic bonding, density functional theory plus Hubbard U correction (DFT + U), energy minimization, molecular dynamics (MD), and Monte Carlo (MD) methods, have also been widely applied to study the radiation effects in various solidified bodies.…”

Section: Introductionmentioning

confidence: 99%

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Review on Selection and Experiment Method of Commonly Studied Simulated Radionuclides in Researches of Nuclear Waste Solidification

Wang

et al. 2020

Science and Technology of Nuclear Installations

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Although many types of simulated radionuclides have been widely used as a substitute for actual nuclear waste in the studies of nuclear waste solidification, the understanding of the applicability and validity of simulated radionuclides is still insufficient. In particular, the selection and use of simulated radionuclides, which can play a decisive role in the accuracy of the experimental results, still lack unified or integrated references. This paper provides a critical review on the selection, experimental methods, and applicability of the most commonly studied simulated radionuclides, followed by a careful discussion and recommendation of simulated radionuclides suitable for different solidified bodies. The main factors (e.g., temperature, pH, and atmosphere) affecting the choice of simulated radionuclides were analyzed in detail. This work helps to integrate the selection and use of simulated radionuclides, and it will be beneficial for improving the effectiveness of nuclide solidification research.

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“…The number of NBO (non-bridging oxygen) and thus the glass materials properties are comfortably modified by the addition of alkali oxides or by doping transition metals. Complex structure in borosilicate glass influences the local environment around alkali ions [1]. So a structural study is necessary to elucidate the properties of binary alkali borosilicate glass.…”

Section: Introductionmentioning

confidence: 99%

Mixed alkali effect on borosilicate glass structure with vanadyl ion as spin probe

Nagamani

Srinivasu

2020

Mater. Res. Express

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Mixed alkali borosilicate glasses doped with 2% vanadium oxide were synthesized by conventional melt-quench method. The Micro structure of the materials was analysed using XRD, SEM and EDX spectrum. Optical nature of glasses was studied by computing optical bandgaps with absorption spectral data. Covalent nature of glasses was estimated correlating optical bandgap energy with EPR spectral data. The metallization criterion of glasses was evaluated from the physical parameters. FTIR and Raman spectral techniques were used to identify the structural groups of the borates and silicates that are formed with addition of modifiers. Emission spectra were recorded at excitation wavelength of 350 nm and their thermal nature was also studied using TGA/DTA techniques.

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Structural analysis of mixed alkali borosilicate glasses containing Cs⁺ and Na⁺ using strong magnetic field magic angle spinning nuclear magnetic resonance

Abstract: analysis of mixed alkali borosilicate glasses containing Cs + and Na + using strong magnetic field magic angle spinning nuclear magnetic resonance,

Cited by 14 publications

References 26 publications

Pressure-Induced Structural Transitions in Na–Li Silicate Glasses under Compression

Pressure-Induced Structural Transitions in Na–Li Silicate Glasses under Compression

Review on Selection and Experiment Method of Commonly Studied Simulated Radionuclides in Researches of Nuclear Waste Solidification

Mixed alkali effect on borosilicate glass structure with vanadyl ion as spin probe

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Structural analysis of mixed alkali borosilicate glasses containing Cs+ and Na+ using strong magnetic field magic angle spinning nuclear magnetic resonance

Abstract: analysis of mixed alkali borosilicate glasses containing Cs + and Na + using strong magnetic field magic angle spinning nuclear magnetic resonance,

Cited by 14 publications

References 26 publications

Pressure-Induced Structural Transitions in Na–Li Silicate Glasses under Compression

Pressure-Induced Structural Transitions in Na–Li Silicate Glasses under Compression

Review on Selection and Experiment Method of Commonly Studied Simulated Radionuclides in Researches of Nuclear Waste Solidification

Mixed alkali effect on borosilicate glass structure with vanadyl ion as spin probe

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Structural analysis of mixed alkali borosilicate glasses containing Cs⁺ and Na⁺ using strong magnetic field magic angle spinning nuclear magnetic resonance