1
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Lv P, Stevensson B, Mathew R, Wang T, Edén M. Sub-Nanometer-Range Structural Effects From Mg 2+ Incorporation in Na-Based Borosilicate Glasses Revealed by Heteronuclear NMR and MD Simulations. J Phys Chem B 2024; 128:6922-6939. [PMID: 38981089 DOI: 10.1021/acs.jpcb.4c01840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) experiments and molecular dynamics (MD) simulations were employed to investigate Na2O-B2O3-SiO2 and MgO-Na2O-B2O3-SiO2 glass structures up to ≈0.3 nm. This encompassed the {Na[p]}, {Mg[p]}, and {B[3], B[4]} speciations and the {Si, B[p], M[p]}-BO and {Si, B[p], M[p]}-NBO interatomic distances to the bridging oxygen (BO) and nonbridging oxygen (NBO) species, where the superscript indicates the coordination number. The MD simulations revealed the dominance of Mg[5] coordinations, as mirrored in average Mg2+ coordination numbers in the 5.2-5.5 range, which are slightly lower than those of the larger Na+ cation but with a narrower coordination distribution stemming from the higher cation field strength (CFS) of the smaller divalent Mg2+ ion. We particularly aimed to elucidate such Na+/Mg2+ CFS effects, which primarily govern the short-range structure but also the borosilicate (BS) glass network order, where both MD simulations and heteronuclear double-resonance 11B/29Si NMR experiments revealed a reduction of B[4]-O-Si linkages relative to B[3]-O-Si upon Mg2+-for-Na+ substitution. These effects were quantified and discussed in relation to previous literature on BS glasses, encompassing the implications for simplified structural models and descriptions thereof.
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Affiliation(s)
- Peng Lv
- MOE Frontiers Science Center for Rare Isotopes, Lanzhou University, Lanzhou, Gansu 730000, PR China
- Key Laboratory of Special Function Materials and Structure Design Ministry of Education, Lanzhou University, Lanzhou, Gansu 730000, PR China
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Baltzar Stevensson
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Renny Mathew
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Tieshan Wang
- MOE Frontiers Science Center for Rare Isotopes, Lanzhou University, Lanzhou, Gansu 730000, PR China
- Key Laboratory of Special Function Materials and Structure Design Ministry of Education, Lanzhou University, Lanzhou, Gansu 730000, PR China
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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Christie JK. Clustering of fluoride and phosphate ions in bioactive glass from computer simulation. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2023; 381:20220345. [PMID: 37634536 PMCID: PMC10460646 DOI: 10.1098/rsta.2022.0345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/30/2023] [Indexed: 08/29/2023]
Abstract
In order to understand the nature of ionic clustering in bioactive glass compositions, computer simulation was used to model four different compositions of bioactive glass with various amounts of flouride and phosphate. Fluoride ions were chemically bonded only to sodium and calcium, creating regions rich in fluoride and modifiers, and fluoride clustering was seen to be present in all compositions. The majority of phosphate groups are present as orthophosphate and phosphate clustering is also seen, and shown to be stronger in compositions with a lower phosphate content. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 1)'.
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3
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Christie JK. Review: understanding the properties of amorphous materials with high-performance computing methods. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2023; 381:20220251. [PMID: 37211037 DOI: 10.1098/rsta.2022.0251] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/20/2023] [Indexed: 05/23/2023]
Abstract
Amorphous materials have no long-range order in their atomic structure. This makes much of the formalism for the study of crystalline materials irrelevant, and so elucidating their structure and properties is challenging. The use of computational methods is a powerful complement to experimental studies, and in this paper we review the use of high-performance computing methods in the simulation of amorphous materials. Five case studies are presented to showcase the wide range of materials and computational methods available to practitioners in this field. This article is part of a discussion meeting issue 'Supercomputing simulations of advanced materials'.
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Affiliation(s)
- J K Christie
- Department of Materials, Loughborough University, Loughborough LE11 3TU, UK
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4
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Krishnamurthy A, Kroeker S. Improving Molybdenum and Sulfur Vitrification in Borosilicate Nuclear Waste Glasses Using Phosphorus: Structural Insights from NMR. Inorg Chem 2021; 61:73-85. [PMID: 34927420 DOI: 10.1021/acs.inorgchem.1c01913] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reclaiming residual fissile materials from spent nuclear fuel rods results in highly radioactive waste that must be immobilized in durable materials to protect the biosphere from harmful environmental exposure. The glasses typically used for this purpose are less effective at incorporating highly charged cations than cations in lower oxidation states. Molybdenum and sulfur solubilities in model aluminoborosilicate nuclear glasses were studied using solid-state nuclear magnetic resonance (NMR) spectroscopy. The extent of molybdenum and sulfur incorporation was significantly improved by doping the glasses with phosphorus, a high-field-strength cation capable of competing with Mo6+ and S6+ for oxygen, resulting in more oxygen sharing and a higher degree of Mo and S integration into the glass network. The addition of 3 mol % each of molybdenum and sulfur to phosphorus-free glasses led to the separation of crystalline sodium molybdates and sodium sulfates, whereas the replacement of 5 mol % SiO2 by P2O5 resulted in complete Mo and S incorporation into the glass, enhancing their respective loading limits by several times. NMR spectroscopy indicates that this improvement originates from the availability of chain phosphates as binding sites. This work demonstrates the value of using phosphate additives to improve Mo and S integration in nuclear glasses, providing insight into its specific structural role and foundational understanding for further development as a material design principle.
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Affiliation(s)
- Arun Krishnamurthy
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Scott Kroeker
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.,Manitoba Institute for Materials, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
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5
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Glatz P, Comte M, Montagne L, Doumert B, Cormier L. Quantitative determination of the phosphorus environment in lithium aluminosilicate glasses using solid-state NMR techniques. Phys Chem Chem Phys 2019; 21:18370-18379. [DOI: 10.1039/c9cp03181b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The phosphorus environment is determined quantitatively using 31P Magic Angle Spinning NMR constrained by 31P–27Al Multiple-Quantum Coherence-based NMR techniques.
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Affiliation(s)
- Pauline Glatz
- Corning European Technology Center
- 7 Bis Avenue de Valvins
- 77210 Avon
- France
- Univ. Lille
| | - Monique Comte
- Corning European Technology Center
- 7 Bis Avenue de Valvins
- 77210 Avon
- France
| | | | - Bertrand Doumert
- Univ. Lille, CNRS
- INRA
- Centrale Lille
- ENSCL
- Univ. Artois, FR 2638 – IMEC – Institut Michel-Eugène Chevreul
| | - Laurent Cormier
- Sorbonne Université
- CNRS, Muséum National d'Histoire Naturelle, IRD
- Institut de Minéralogie
- de Physique des Matériaux et de Cosmochimie (IMPMC)
- UMR 7590
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6
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Abstract
In 2005, our group described for the first time the structural characterization at the atomic scale of bioactive glasses and the influence of the glasses’ nanostructure in their reactivity in simulated body fluids. In that study, two bioactive sol-gel glasses with composition 80%SiO2–20%CaO and 80%SiO2–17%CaO–3%P2O5 (in mol-%) were characterized by High-Resolution Transmission Electron Microscopy (HRTEM). Such characterization revealed unknown features of the glasses’ structure at the local scale that allowed the understanding of their different in vitro behaviors as a consequence of the presence or absence of P2O5. Since then, the nanostructure of numerous bioactive glasses, including melt-prepared, sol-gel derived, and mesoporous glasses, was investigated by HRTEM, Nuclear Magnetic Resonance (NMR) spectroscopy, Molecular Dynamics (MD) simulations, and other experimental techniques. These studies have shown that although glasses are amorphous solids, a certain type of short distance order, which greatly influences the in vitro and in vivo reactivity, is always present. This paper reviews the most significant advances in the understanding of bioactive glasses that took place in the last years as a result of the growing knowledge of the glasses’ nanostructure.
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7
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Stevensson B, Yu Y, Edén M. Structure–composition trends in multicomponent borosilicate-based glasses deduced from molecular dynamics simulations with improved B–O and P–O force fields. Phys Chem Chem Phys 2018. [DOI: 10.1039/c7cp08593a] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Improved B–O and P–O force fields provide accurate molecular dynamics simulations of multicomponent glasses.
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Affiliation(s)
- Baltzar Stevensson
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Yang Yu
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Mattias Edén
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Stockholm University
- SE-106 91 Stockholm
- Sweden
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Yu Y, Stevensson B, Edén M. Medium-Range Structural Organization of Phosphorus-Bearing Borosilicate Glasses Revealed by Advanced Solid-State NMR Experiments and MD Simulations: Consequences of B/Si Substitutions. J Phys Chem B 2017; 121:9737-9752. [PMID: 28876931 DOI: 10.1021/acs.jpcb.7b06654] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The short and intermediate range structures of a large series of bioactive borophosphosilicate (BPS) glasses were probed by solid-state nuclear magnetic resonance (NMR) spectroscopy and atomistic molecular dynamics (MD) simulations. Two BPS glass series were designed by gradually substituting SiO2 by B2O3 in the respective phosphosilicate base compositions 24.1Na2O-23.3CaO-48.6SiO2-4.0P2O5 ("S49") and 24.6Na2O-26.7CaO-46.1SiO2-2.6P2O5 ("S46"), the latter constituting the "45S5 Bioglass" utilized for bone grafting applications. The BPS glass networks are built by interconnected SiO4, BO4, and BO3 moieties, whereas P exists mainly as orthophosphate anions, except for a minor network-associated portion involving P-O-Si and P-O-B[4] motifs, whose populations were estimated by heteronuclear 31P{11B} NMR experimentation. The high Na+/Ca2+ contents give fragmented glass networks with large amounts of nonbridging oxygen (NBO) anions. The MD-generated glass models reveal an increasing propensity for NBO accommodation among the network units according to BO4 < SiO4 < BO3 ≪ PO4. The BO4/BO3 intermixing was examined by double-quantum-single-quantum correlation 11B NMR experiments, which evidenced the presence of all three BO3-BO3, BO3-BO4, and BO4-BO4 connectivities, with B[3]-O-B[4] bridges dominating. Notwithstanding that B[4]-O-B[4] linkages are disfavored, both NMR spectroscopy and MD simulations established their presence in these modifier-rich BPS glasses, along with non-negligible B[4]-NBO contacts, at odds with the conventional structural view of borosilicate glasses. We discuss the relative propensities for intermixing of the Si/B/P network formers. Despite the absence of pronounced preferences for Si-O-Si bond formation, the glass models manifest subtle subnanometer-sized structural inhomogeneities, where SiO4 tetrahedra tend to self-associate into small chain/ring motifs embedded in BO3/BO4-dominated domains.
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Affiliation(s)
- Yang Yu
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden
| | - Baltzar Stevensson
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden
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9
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Mathew R, Turdean-Ionescu C, Yu Y, Stevensson B, Izquierdo-Barba I, García A, Arcos D, Vallet-Regí M, Edén M. Proton Environments in Biomimetic Calcium Phosphates Formed from Mesoporous Bioactive CaO-SiO 2-P 2O 5 Glasses in Vitro: Insights from Solid-State NMR. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:13223-13238. [PMID: 28663772 PMCID: PMC5484558 DOI: 10.1021/acs.jpcc.7b03469] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/23/2017] [Indexed: 05/26/2023]
Abstract
When exposed to body fluids, mesoporous bioactive glasses (MBGs) of the CaO-SiO2-P2O5 system develop a bone-bonding surface layer that initially consists of amorphous calcium phosphate (ACP), which transforms into hydroxy-carbonate apatite (HCA) with a very similar composition as bone/dentin mineral. Information from various 1H-based solid-state nuclear magnetic resonance (NMR) experiments was combined to elucidate the evolution of the proton speciations both at the MBG surface and within each ACP/HCA constituent of the biomimetic phosphate layer formed when each of three MBGs with distinct Ca, Si, and P contents was immersed in a simulated body fluid (SBF) for variable periods between 15 min and 30 days. Directly excited magic-angle-spinning (MAS) 1H NMR spectra mainly reflect the MBG component, whose surface is rich in water and silanol (SiOH) moieties. Double-quantum-single-quantum correlation 1H NMR experimentation at fast MAS revealed their interatomic proximities. The comparatively minor H species of each ACP and HCA component were probed selectively by heteronuclear 1H-31P NMR experimentation. The initially prevailing ACP phase comprises H2O and "nonapatitic" HPO42-/PO43- groups, whereas for prolonged MBG soaking over days, a well-progressed ACP → HCA transformation was evidenced by a dominating O1H resonance from HCA. We show that 1H-detected 1H → 31P cross-polarization NMR is markedly more sensitive than utilizing powder X-ray diffraction or 31P NMR for detecting the onset of HCA formation, notably so for P-bearing (M)BGs. In relation to the long-standing controversy as to whether bone mineral comprises ACP and/or forms via an ACP precursor, we discuss a recently accepted structural core-shell picture of both synthetic and biological HCA, highlighting the close relationship between the disordered surface layer and ACP.
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Affiliation(s)
- Renny Mathew
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Claudia Turdean-Ionescu
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Yang Yu
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Baltzar Stevensson
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Isabel Izquierdo-Barba
- Departamento
de Química Inorgánica y Bioinorgánica,
Facultad de Farmacia, Universidad Complutense
de Madrid, Instituto
de Investigación Sanitaria Hospital 12 de Octubre i+12, 28040 Madrid, Spain
- Networking
Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - Ana García
- Departamento
de Química Inorgánica y Bioinorgánica,
Facultad de Farmacia, Universidad Complutense
de Madrid, Instituto
de Investigación Sanitaria Hospital 12 de Octubre i+12, 28040 Madrid, Spain
- Networking
Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - Daniel Arcos
- Departamento
de Química Inorgánica y Bioinorgánica,
Facultad de Farmacia, Universidad Complutense
de Madrid, Instituto
de Investigación Sanitaria Hospital 12 de Octubre i+12, 28040 Madrid, Spain
- Networking
Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - María Vallet-Regí
- Departamento
de Química Inorgánica y Bioinorgánica,
Facultad de Farmacia, Universidad Complutense
de Madrid, Instituto
de Investigación Sanitaria Hospital 12 de Octubre i+12, 28040 Madrid, Spain
- Networking
Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - Mattias Edén
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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10
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Yu Y, Edén M. Structure–composition relationships of bioactive borophosphosilicate glasses probed by multinuclear 11B, 29Si, and 31P solid state NMR. RSC Adv 2016. [DOI: 10.1039/c6ra15275a] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
By combining 11B, 29Si, and 31P nuclear magnetic resonance (NMR) experimental results, we present the first comprehensive structural investigation of 15 borophosphosilicate (BPS) glasses of the Na2O–CaO–B2O3–SiO2–P2O5 system.
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Affiliation(s)
- Yang Yu
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Mattias Edén
- Physical Chemistry Division
- Department of Materials and Environmental Chemistry
- Stockholm University
- SE-106 91 Stockholm
- Sweden
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11
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Ren J, Eckert H. Applications of DQ-DRENAR for the structural analysis of phosphate glasses. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2015; 72:140-147. [PMID: 26499362 DOI: 10.1016/j.ssnmr.2015.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A new solid state NMR technique entitled DQ-DRENAR (Double-Quantum based Dipolar Recoupling Effects Nuclear Alignment Reduction) has been recently described for measuring homonuclear dipole-dipole interactions in multi-spin-1/2 systems under magic-angle spinning conditions. As in rotational echo double resonance (REDOR), the homonuclear dipole-dipole coupling constant can be extracted from a plot of a normalized difference signal (S0-S')/S0 versus dipolar mixing time, where S is the signal amplitude with the DQ-Hamiltonian present, and S0 is the signal amplitude in the absence of the DQ-Hamiltonian, which is used for normalization. Within the range of (S0-S)/S0≤0.3-0.5 such "homonuclear REDOR curves" can be approximated by simple parabolae, yielding effective squared dipole-dipole coupling constants ∑bjk(2) summed over all the pairwise interactions present. The effect of glassy disorder has been studied by simulations, replacing singular-valued internuclear distances by Gaussian distance distributions with the same central value. This situation results in a systematic over-estimation effect, which tends to compensate the implicit under-estimation effect caused by the parabolic fitting approach. The present contribution describes applications to a number of phosphate-based glasses and glass ceramics. The method turns out to be well suited for the differentiation of the various Q((n)) phosphate species, for characterizing the spatial distribution of isolated orthophosphate ions and for the detection of incipient nano-segregation and/or phase separation effects in glass ceramics.
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Affiliation(s)
- Jinjun Ren
- Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, D-48149 Münster, Germany; Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
| | - Hellmut Eckert
- Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, D-48149 Münster, Germany; Instituto de Física de São Carlos, Universidade de São Paulo (USP), C.P. 369, CEP 13566-590 São Carlos, SP, Brazil.
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12
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Mathew R, Stevensson B, Edén M. Na/Ca Intermixing around Silicate and Phosphate Groups in Bioactive Phosphosilicate Glasses Revealed by Heteronuclear Solid-State NMR and Molecular Dynamics Simulations. J Phys Chem B 2015; 119:5701-15. [PMID: 25815412 DOI: 10.1021/acs.jpcb.5b01130] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We characterize the intermixing of network-modifying Na(+)/Ca(2+) ions around the silicate (QSi(n)) and phosphate (QP(n)) tetrahedra in a series of 16 Na2O–CaO–SiO2–P2O5 glasses, whose P content and silicate network connectivity were varied independently. The set includes both bioactive and bioinactive compositions and also encompasses two soda-lime-silicate members devoid of P, as well as two CaO–SiO2 glasses and one Na2O–SiO2–P2O5 glass. The various Si/P↔Na/Ca contacts were probed by molecular dynamics (MD) simulations together with heteronuclear magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) experimentation utilizing (23)Na{(31)P} and (23)Na{(29)Si} REDOR, as well as (31)P{ (23)Na} and (29)Si{(23)Na} REAPDOR. We introduce an approach for quantifying the extent of Na(+)/Ca(2+) ordering around a given QP(n) or QSi(n) group, encoded by the preference factor 0⩽ PM ⩽ 1 conveying the relative weights of a random cation intermixing (PM = 0) and complete preference/ordering (PM = 1) for one of the species M, which represents either Na(+) or Ca(2+). The MD-derived preference factors reveal phosphate and silicate species surrounded by Na(+)/Ca(2+) ions intermixed nearly randomly (PM ≲ 0.15), except for the QSi(4) and QSi(1) groups, which manifest more significant cation ordering with preference for Na+ and Ca2+, respectively. The overall weak preferences are essentially independent of the Si and P contents of the glass, whereas PM primarily correlates with the total amount of network modifiers: as the latter is increased, the Na/Ca distribution around the {QP(0), QSi(1), QSi(2)} groups with preference for Ca2(+ )tend to randomize (i.e., PCa decreases), while the PNa-values grow slightly for the {QP(1), QSi(3), QSi(4)} species already preferring coordination of Na. The set of experimental preference factors {PCa} for the orthophosphate (QP(0)) groups extracted from (31)P{(23)Na} REAPDOR NMR-derived M2(P–Na) dipolar second moments agrees well with the MD-generated counterparts. Our results on the Na/Ca intermixing in soda-lime-silicate glasses are discussed in relation to previous reports, highlighting the dependence of the conclusion on the approach to data evaluation.
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Affiliation(s)
- Renny Mathew
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Baltzar Stevensson
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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13
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Stevensson B, Mathew R, Yu Y, Edén M. Two heteronuclear dipolar results at the price of one: quantifying Na/P contacts in phosphosilicate glasses and biomimetic hydroxy-apatite. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 251:52-56. [PMID: 25557863 DOI: 10.1016/j.jmr.2014.12.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 12/01/2014] [Accepted: 12/03/2014] [Indexed: 06/04/2023]
Abstract
The analysis of S{I} recoupling experiments applied to amorphous solids yields a heteronuclear second moment M(2)(S-I) that represents the effective through-space dipolar interaction between the detected S spins and the neighboring I-spin species. We show that both M(2)(S-I) and M(2)(I-S) values are readily accessible from a sole S{I} or I{S} experiment, which may involve either S or I detection, and is naturally selected as the most favorable option under the given experimental conditions. For the common case where I has half-integer spin, an I{S} REDOR implementation is preferred to the S{I} REAPDOR counterpart. We verify the procedure by (23)Na{(31)P} REDOR and (31)P{(23)Na} REAPDOR NMR applied to Na(2)O-CaO-SiO(2)-P(2)O(5) glasses and biomimetic hydroxyapatite, where the M(2)(P-Na) values directly determined by REAPDOR agree very well with those derived from the corresponding M(2)(Na-P) results measured by REDOR. Moreover, we show that dipolar second moments are readily extracted from the REAPDOR NMR protocol by a straightforward numerical fitting of the initial dephasing data, in direct analogy with the well-established procedure to determine M(2)(S-I) values from REDOR NMR experiments applied to amorphous materials; this avoids the problems with time-consuming numerically exact simulations whose accuracy is limited for describing the dynamics of a priori unknown multi-spin systems in disordered structures.
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Affiliation(s)
- Baltzar Stevensson
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Renny Mathew
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Yang Yu
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Mattias Edén
- Physical Chemistry Division, Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden.
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14
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Turdean-Ionescu C, Stevensson B, Grins J, Izquierdo-Barba I, García A, Arcos D, Vallet-Regí M, Edén M. Composition-dependent in vitro apatite formation at mesoporous bioactive glass-surfaces quantified by solid-state NMR and powder XRD. RSC Adv 2015. [DOI: 10.1039/c5ra13410b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Solid-state NMR and powder XRD are employed to quantify the ACP (amorphous calcium phosphate) and HCA (hydroxy-carbonate apatite) components grown from three mesoporous bioactive glasses with variable compositions.
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Affiliation(s)
- Claudia Turdean-Ionescu
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Baltzar Stevensson
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Jekabs Grins
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Isabel Izquierdo-Barba
- Departamento de Química Inorgánica y Bioinorgánica
- Facultad de Farmacia
- Universidad Complutense de Madrid
- Instituto de Investigación Sanitaria Hospital 12 de Octubre i+12
- 28040 Madrid
| | - Ana García
- Departamento de Química Inorgánica y Bioinorgánica
- Facultad de Farmacia
- Universidad Complutense de Madrid
- Instituto de Investigación Sanitaria Hospital 12 de Octubre i+12
- 28040 Madrid
| | - Daniel Arcos
- Departamento de Química Inorgánica y Bioinorgánica
- Facultad de Farmacia
- Universidad Complutense de Madrid
- Instituto de Investigación Sanitaria Hospital 12 de Octubre i+12
- 28040 Madrid
| | - María Vallet-Regí
- Departamento de Química Inorgánica y Bioinorgánica
- Facultad de Farmacia
- Universidad Complutense de Madrid
- Instituto de Investigación Sanitaria Hospital 12 de Octubre i+12
- 28040 Madrid
| | - Mattias Edén
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- SE-106 91 Stockholm
- Sweden
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