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Effect of boron content on atomic structure of boron-bearing multicomponent oxide glasses: A view from the solid-state NMR : 붕소를 함유한 용융체의 원자 환경 규명을 통한 마그마의 이동 물성의 미시적 근원
DC Field | Value | Language |
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dc.contributor.advisor | 이성근 | - |
dc.contributor.author | 이아침 | - |
dc.date.accessioned | 2017-07-19T08:57:05Z | - |
dc.date.available | 2017-07-19T08:57:05Z | - |
dc.date.issued | 2017-02 | - |
dc.identifier.other | 000000142528 | - |
dc.identifier.uri | https://hdl.handle.net/10371/131446 | - |
dc.description | 학위논문 (석사)-- 서울대학교 대학원 : 지구환경과학부, 2017. 2. 이성근. | - |
dc.description.abstract | Understanding the effect of boron content on atomic structures of boron-bearing multicomponent silicate melts is essential to reveal the atomistic origins of diverse geochemical processes involving silica-rich magmas, such as explosive volcanic eruption and the reaction of magma in contact with aqueous solutions. It is also considered crucial in environmental science because a nuclear waste glasses contain B2O3. Despite the importance, the detailed atomic structure of boron-bearing multicomponent silicate glasses remains unsolved. We report experimental results on the effect of boron content on the atomic structures of sodium borate glasses and boron-bearing multicomponent silicate melts [nepheline (NaAlSiO4)- malinkoite (NaBSiO4) and albite (NaAlSi3O8)- reedmergnerite (NaBSi3O8) pseudo-binary glasses] using the high-resolution solid-state NMR (11B, 27Al, and 17O). The 11B NMR spectra of Na2O-B2O3 glasses show that four-coordinated boron ([4]B) increases at the expense of ring (three-coordinated boron, [3]B) not of non-ring ([3]B) with increasing sodium content based on the new interpretation from the results of quantum chemical calculations that 11B NMR chemical shift of non-ring ([3]B) increases with increasing sodium content. The two topological species of [4]B are firstly observed in 11B 3QMAS NMR spectra for Na2O-B2O3 glasses. The 11B NMR spectra of NaAlSiO4-NaBSiO4 and NaAlSi3O8-NaBSi3O8 glasses show that [4]B increases as boron content increases while non-ring ([3]B) decreases. 27Al MAS NMR spectra for NaAlSiO4-NaBSiO4 glasses confirm that four-coordinated aluminum ([4]Al) is dominant. It is also observed that a drastic decrease in the peak widths (full-width at half-maximum, FWHM) of [4]Al with an addition of boron into nepheline glasses, indicating a decrease in structural and topological disorder around [4]Al. The quantitative atomic environments around boron of multicomponent glasses are estimated from the simulation results of 11B MAS NMR spectra, revealing complex-nonlinear variation of boron topology with varying composition. 17O MAS and 3QMAS NMR spectra for NaAlSiO4-NaBSiO4 glasses show that Na-O-Si, B-O-B, and B-O-Si increase with increasing boron content, indicating that a drastic increase in dissolution rate might be due to an increase in B-O-B and B-O-Si which are relatively weaker bridging oxygen (BOs). An increase in non-bridging oxygen (NBO), Na-O-Si, implying a decrease in the degree of polymerization can explain the low viscosity of boron-bearing silicate melts. Na-O-B is firstly observed in 17O 3QMAS NMR spectra for NaAl0.25B0.75SiO4 glasses. The current experimental results with the changes in coordination environment, topological structure, and network connectivity in the nepheline-malinkoite and albite-reedmergnerite glasses can improve understanding of the structure-property relationships including dissolution and viscosity of multicomponent boron-bearing silicate melts. | - |
dc.description.tableofcontents | 1. INTRODUCTION 1
2. EXPERIMENTAL METHOD 5 2.1. Sample preparation 5 2.2. Previous peak assignment of non-ring species in 11B NMR spectrum 11 2.3. Spectrometer 11 3. RESULTS 13 3.1. Effects of Na on 11B NMR chemical shift of non-ring ([3]B) in Na2O-B2O3 glasses and melts: A view from 11B MAS and 3QMAS NMR results and quantum chemical calculations 13 3.2. Effect of boron fraction [B/(B+Al)] on B coordination environments in boron-bearing nepheline (NaAlSiO4-NaBSiO4) glasses and melts: Insights from 11B MAS and 3QMAS NMR results 14 3.3. Effect of boron fraction [B/B+Al] on Al coordination environments in boron-bearing nepheline (NaAlSiO4-NaBSiO4) glasses and melts: Insights from 27Al MAS and 3QMAS NMR results 21 3.4. Effect of boron fraction [B/(B+Al)] on extent of network connectivity and disorder in boron-bearing nepheline (NaAlSiO4-NaBSiO4) glasses and melts: Insights from 17O MAS and 3QMAS NMR results 26 3.5. Effect of boron content on B coordination environments in boron-bearing albite (NaAlSi3O8-NaBSi3O8) glasses and melts: Insights from 11B MAS and 3QMAS NMR results 34 4. DISCUSSION 39 4.1. New interpretation of 11B NMR spectra for boron-bearing glasses containing non-framework cation based on quantum chemical calculations 39 4.2. Insights into dissolution rate and viscosity of boron-bearing sodium aluminosilicate melts based on boron environment and oxygen network connectivity 39 5. CONCLUSION 43 References 44 Appendix 68 국문 초록 64 | - |
dc.format | application/pdf | - |
dc.format.extent | 3725070 bytes | - |
dc.format.medium | application/pdf | - |
dc.language.iso | en | - |
dc.publisher | 서울대학교 대학원 | - |
dc.subject | Sodium borate glasses | - |
dc.subject | boron-bearing multicomponent silicate melts (nepheline-malinkoite and albite-reedmergnerite pseudo-binary glasses) | - |
dc.subject | NMR | - |
dc.subject | atomic structure | - |
dc.subject.ddc | 550 | - |
dc.title | Effect of boron content on atomic structure of boron-bearing multicomponent oxide glasses: A view from the solid-state NMR | - |
dc.title.alternative | 붕소를 함유한 용융체의 원자 환경 규명을 통한 마그마의 이동 물성의 미시적 근원 | - |
dc.title.alternative | 고상 핵자기 공명 분광분석 | - |
dc.type | Thesis | - |
dc.description.degree | Master | - |
dc.citation.pages | 73 | - |
dc.contributor.affiliation | 자연과학대학 지구환경과학부 | - |
dc.date.awarded | 2017-02 | - |
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