| 壳聚糖基过渡金属复合膜微结构的正电子湮没谱学研究 |
| Alternative Title | Study of Microstructure for Chitosan Metal Complexes by PAT
|
| 田红伟 |
| Thesis Advisor | 安钧鸿
|
| 2016-05-31
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| Degree Grantor | 兰州大学
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| Place of Conferral | 兰州
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| Degree Name | 硕士
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| Keyword | 壳聚糖
过渡金属
微结构
电子偶素
自由体积
|
| Abstract | 本论文中，我们研究了壳聚糖基过渡金属配合高聚物中金属离子与壳聚糖的不同配比、阴离子和金属离子种类对这种配合物结构的影响，利用红外吸收光谱、紫外可见吸收光谱、X 射线粉末衍
射及吸水膨胀性能测试对壳聚糖基过渡金属配合物的结构进行了表征，依此提出合理的物理结构模型；同时我们重点分析聚合物金属复合材料中氯离子、硝酸根离子和醋酸根离子对电子偶素的形成及湮没的影响，揭示正电子湮没测量技术在复杂体系研究的适用性。具体内容如下：
1. 利用溶胶凝胶方法在真空干燥条件下制备壳聚糖钯薄膜催化材料，对比分析壳聚糖钯催化薄膜样品和壳聚糖吸附钯粉末样品中电子偶素寿命及强度变化，说明配合物薄膜中氯离子的存在对电子偶素的形成有抑制作用。
2. 应用正电子湮没寿命谱测量技术和符合多普勒展宽能谱测量技术，结合FTIR、XRD、UV-vis 和吸水膨胀性的测试，研究了壳聚糖镍配合物薄膜的结构：结晶性、金属离子与壳聚糖相互作用。在此基础上，重点研究薄膜材料中氯离子、硝酸根离子或醋酸根离子存在时，聚合体系中正电子湮没特性，发现阴离子抑制电子偶素的形成，在阴离子含量增加时，电子偶素寿命值在表征材料中自由体积特性方面则失去意义。
3. 着重研究了在少量阴离子存在的配合物中，不同种类金属配合物中, 正电子湮没符合多普勒展宽能谱的变化。含有氯离子或硝酸根离子的配合物中阴离子对正电子湮没处化学环境的变化起主要作用，含有醋酸根离子的金属配合物中，金属种类不同其CDB 商谱的峰形和峰位完全不同。 |
| Other Abstract | Positron annihilation technique(PAT) is a unique sensible method to probe
defects or free volume properties in materials based on time and momentum information
of photons produced by positron-electron annihilation. It is of great
significance to explore application of PAT in functional polymeric system. The
study of positron annihilation mechanism is necessary due to the complicated
process of positronium formation and annihilation in polymers.In this thesis,we
investigate the structure and water sorption capability of chitosan metal complexes
with different metal contents ,different metal species and salt by FTIR,XRD,
UV-vis and PAT . In addition,we have emphasized to study formation and annihilation
of positronium in polymeric system with .The main contents as follows:
1. Chitosan-Pd2+ complexes with various Pd2+ concentrations were prepared
through the sol-gel method.The change of positronium annihilation lifetime
and intensity with metal contents increasing has been discussed in comparison
with that of power samples.Finally,the conclusion is obtained that Cl
in complexes is a main inhibitor for positronium formation.
2. Metal interaction with chitosan was studied by FTIR and UV-vis in chitosan-
Ni complexes with various metal ions contents.Crystallinity of complexes has
intimate connection with metal contents explored by XRD.Furthermore, formation
of positronium is inhibited by the existence of NO
3 /Cl /Ac in the
polymeric system. Meanwhile, positronium lifetime is invalid to estimate
free volume size in materials based on semiempirical equation. In addition,
CDB is fully sensitive to chemical composition in the complexes.
3. Chemical environment in positron annihilation sites of Co2+,Ni2+,Cu2+ and
Zn2+ supported chitosan complexes was investigated by coincident Doppler |
| URL | 查看原文
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| Language | 中文
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| Document Type | 学位论文
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| Identifier | https://ir.lzu.edu.cn/handle/262010/229647
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| Collection | 物理科学与技术学院
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Recommended Citation
GB/T 7714 |
田红伟. 壳聚糖基过渡金属复合膜微结构的正电子湮没谱学研究[D]. 兰州. 兰州大学,2016.
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