固态核磁共振技术对近红外光功能玻璃的结构研究
文献类型：学位论文
| 作者 | 张瑞丽 |
| 文献子类 | 博士 |
| 导师 | 任进军、张龙 |
| 关键词 | 固态核磁共振 solid state NMR 光功能玻璃 optical functional glass 铋掺杂 Bismuth 氟氧玻璃 structure 结构 oxyfluoride glass |
| 其他题名 | Structural Studies of Near-Infrared Luminescent Optical Functional Glasses by Solid State NMR |
| 英文摘要 | 活性离子（包括铋离子、稀土离子等）掺杂的氧化物玻璃在光通讯、三维（3D）显示、激光及太阳能电池等领域有广泛的应用。目前的研究主要集中在材料的制备及光学性能方面，光学性能与玻璃的结构密切相关，但是目前对玻璃结构的研究还非常少。现代先进的固态核磁共振技术有非常丰富的结构解析方法，具有强大的玻璃近、中程结构解析功能，能反映研究核周围的局部环境，可以提供原子分子水平的结构信息，非常适合于研究固体材料的微观结构。本课题运用多种先进的1、2维固态核磁共振技术分析手段，对铋掺杂、稀土离子掺杂的玻璃进行原子级别超精细结构解析，提出了玻璃微观结构随玻璃组成改变的演化模型，同时测量玻璃的各种光谱性能，研究比较玻璃光谱性能随玻璃组分改变而变化的规律，发现了玻璃光谱性能与玻璃组成、微观结构之间的内在关联，最终通过选择性地设计玻璃组成，实现对玻璃光谱性能的调控。这对进一步推动光通讯领域的发展以及高转换效率的太阳能下转换材料有重要意义。 在第一章中，对光功能玻璃进行了综述。 在第二章中，对核磁共振基本理论和方法进行了综述。 在第三章中，通过高温熔融法制备xBi2O3–(100-x)NaPO3体系的玻璃，并采用固态核磁共振（SSNMR）技术、x射线光电子能谱（XPS）以及红外光谱（FT-IR）进行表征。Bi2O3的加入导致磷链的解聚，形成Q(n)（n = 0, 1, 2）磷结构单元（这里n表示P-O-P键的数目），并且通过31P MAS NMR和CT-DQ-DRENAR对Q(n)进行定量分析。23Na{31P}，31P{23Na}和XPS结果一致证明Na+和Bi3+离子都被磷氧四面体[PO4]3-包围。与其它三价阳离子如Ga3+和Al3+通过共顶方式与磷氧四面体连接不同，通过31P谱的实验结果，以及考虑电荷平衡和键价，Bi3+离子首次被证明与磷氧四面体共棱连接。这种连接性的不同导致显著的结构差异。 在第四章中，我们用传统的熔融淬冷法制备了组成为xBi2O3–yAl2O3-(100-x-y)NaPO3的玻璃。通过SSNMR与XPS技术解析了玻璃原子级别的结构，测量了玻璃的红外发光性能。Bi2O3与Al2O3的加入打断了偏磷酸钠的二维长链，磷酸玻璃的随着Bi2O3与Al2O3含量的增加，玻璃网络结构逐步按Q2?Q1?Q0演变。23Na{31P} REDOR, 31P{23Na} REDOR, 27Al{31P} REDOR以及XPS 结果一致证明：Na+, Al3+,与 Bi3+离子主要起网络修饰体补偿磷氧四面体负电荷的作用，它们之间没有并没有形成大量的键连接。酸性较弱的Al2O3代替部分NaPO3，红外发光显著增强，与过去普遍认为的光学碱度降低有利于铋的红外发光的共识相反，在这里玻璃平均的光学碱度降低并没有促进Bi红外活性中心的产生。但是我们发现Al2O3代替部分NaPO3，虽然玻璃的平均光学碱度升高，但是Bi3+离子周围局部环境的光学碱度减低。我们认为Al3+促进铋的红外活性中心的生成主要是因为降低了Bi周围局部环境的光学碱度。 在第五章中，使用硝酸铋，乳酸铝，磷酸三乙酯和正硅酸四乙酯（TEOS）作为前驱体，通过溶胶-凝胶法制备了组成为Bi2O3-AlPO4-SiO2的铋掺杂准二元体系玻璃。通过先进的固态核磁共振技术测量解析了玻璃原子级别的结构。NMR结果表明所制备的玻璃由AlPO4和SiO2纳米团簇组成。通过27Al{31P} REDOR，31P{27Al} REAPDOR，31P CT-DRENAR-BABA-xy16，29Si MAS实验结果证明：Bi2O3的加入促进AlPO4团簇逐步增大直到最后形成明显的分相，Bi2O3同时存在于SiO2和AlPO4两相中。 在第六章中，通过固态NMR和EPR对 (100-x)B2O3-xPbF2 (x = 30, 40, 50)和50B2O3-(50-x)PbO-xPbF2 (x = 5, 10, 15, 20, 25, 30, 35, 40, 45) 玻璃体系进行了结构研究。基于11B 和 19F高分辨固态NMR以及11B/19F双共振的实验结果，我们建立了玻璃原子级别的定量结构描述。19F NMR结果表明：当PbF2含量较低时，F-离子主要存在于BO3/2F-结构单元中，而PbF2含量较高时，氟倾向于在富含PbF2无定形区域中。此外，Yb3+掺杂玻璃的脉冲EPR和Eu3+掺杂玻璃样品的光谱研究表明稀土离子在混合的氟/硼配位环境中，而且玻璃中不存在纳米相分离效应。 在第七章中，对本论文的研究工作进行了全面总结，并对实验中有待进一步深入研究的问题和下一阶段的研究工作进行了展望。; Activated ions (including bismuth ions, rare earth ions etc.) doped oxide glass have attracted considerable interest in optical communications, three (3D) display, laser and solar cells and other fields. In previous reports, the main focus has been on the synthesis and optical characterization of the near-infrared luminescent optical functional glasses owing to their excellent physical properties. Despite this considerable interest, a fundamental understanding of these properties on the basis of the structural organization of these glasses is still missing. Solid state nuclear magnetic resonance (NMR) spectroscopy has proven to be a powerful tool in addressing such structural issues, especially for disordered materials, due to its well-proven ability to provide local structural information. In this paper, we have used 1 and 2D advanced solid-state nuclear magnetic resonance (SSNMR), to precisely investigate the structure of near-infrared luminescent optical functional glasses atomic levels. In Chapter I, we make a brief introduction on the concept of optical functional glasses. In Chapter II, we make a brief introduction on the basics of solid NMR and methods of NMR spectroscopy. In Chapter III, glasses in the system xBi2O3–(100-x)NaPO3 were prepared using transitional melting?quenching and characterized using solid state nuclear magnetic resonance (SSNMR), x-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FT-IR). The addition of Bi2O3 results in the depolymerization of the phosphorus chain and the formation of Q(n) (n = 0, 1, 2) phosphorus species, where n represents the number of P-O-P bonds that can be quantified using 31P magic angle spinning (MAS) NMR and constant-time double-quantum based dipolar recoupling effects nuclear alignment reduction (CT-DQ-DRENAR). The 23Na{31P}REROR, 31P{23Na} REROR, and XPS results consistently prove that both Na+ and Bi3+ ions are bounded by phosphorus tetrahedron [PO4]3-. Unlike other trivalent ions such as Ga3+ and Al3+, which connect with the phosphorus tetrahedron by corner-sharing, Bi3+ ions were first proved to share edge with the phosphorus tetrahedron by the analysis of 31P spectra, taking the charge balance and bond valance consideration into account. Such a difference in connectivity results in significant structural differences. In Chapter IV, the structure of the glass in the system xBi2O3–yAl2O3-(100-x-y)NaPO3 has been studied by SSNMR and XPS techniques. The infrared luminescence properties of the glass were also investigated. Alloying Bi2O3 and Al2O3 into NaPO3 results in the depolymerization of phosphorus chain of NaPO3 and the evolution of phosphorus species in the process of Q2→Q1→Q0. 23Na{31P} REDOR, 31P{23Na} REDOR, 27Al{31P} REDOR and XPS results have consistently proved that Na+, Al3+, and Bi3+ ions mainly act as glass modifiers to neutralize the negative charge of phosphorus tetrahedrons [PO4]3-. No linkage was formed between them. The fluorescent intensity was significantly improved after the addition of weakly acidic Al2O3. Contrary to the consensus that the optical basicity decreasing was favorable for the infrared emission of bismuth, the average optical basicity reduction of the glass does not contribute to the production of the Bi infrared active center. However, we found that when the NaPO3 is partly substituted for Al2O3, although the average optical basicity of the glass increased, but optical basicity of the local environment around Bi3+ ions decreased. We believe that the formation of Al3+ promoting the activity of bismuth infrared activity is mainly due to the reduction of the optical basicity of the local environment around Bi. In Chapter V, bismuth doped quasi-binary system glasses along the composition line Bi2O3-AlPO4-SiO2 were prepared by sol-gel process using bismuth nitrate, aluminum lactate, triethyl phosphate and tetraethyl orthosilicate (TEOS) as precursors. The structure of the glasses is studied by advanced solid-state NMR techniques. The NMR results indicate that the structure of the prepared glass is composed of AlPO4- and SiO2-nanodomains. 27Al{31P} REDOR, 31P{27Al} REAPDOR, 31P CT-DRENAR-BABA-xy16, 29Si MAS results indicate that the addition of Bi2O3 promotes the gradual increase of AlPO4 clusters until the final phase formation is formed, and Bi2O3 exists both in SiO2 and AlPO4 nanodomains. In Chapter VI, the structure of glasses in the system (100-x)B2O3-xPbF2 (x = 30, 40, 50) and 50B2O3-(50-x)PbO-xPbF2 (x = 5, 10, 15, 20, 25, 30, 35, 40 and 45) has been studied by solid state NMR and EPR spectroscopies. Based on 11B and 19F high resolution solid state NMR as well as on 11B/19F double resonance results, we develop a quantitative structural description on the atomic scale. 19F NMR results indicate a systematic dependence of the fluoride speciation on PbF2 content: At low x-values, F- ions are predominantly found on BO3/2F- units, whereas at higher x-values, fluoride tends to be sequestrated into amorphous domains rich in PbF2. In addition, both pulsed EPR studies of Yb3+ doped glasses and photophysical studies of Eu3+ doped samples indicate a mixed fluoride/borate coordination of the rare-earth ions and the absence of nanophase segregation effects. In Chapter VII, we summarize our research on structural studies of optical functional glasses by solid state NMR and foresee the possible development in the future. |
| 学科主题 | 材料学 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/31006]  |
| 专题 | 中国科学院上海光学精密机械研究所 |
| 作者单位 | 中国科学院上海光学精密机械研究所 |
| 推荐引用方式 GB/T 7714 | 张瑞丽. 固态核磁共振技术对近红外光功能玻璃的结构研究[D]. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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