自组装介孔薄膜与自组装聚电解质薄膜的掠入射X射线散射研究
发布时间：2018-08-25 13:21
【摘要】：掠入射X射线散射是薄膜材料结构表征的重要手段之一，具有测试过程中对样品无损、能提供大面积表面结构的统计信息等优点，通过与同步辐射光源相结合可以实现对原位过程结构演变的观察，因此，掠入射X射线散射技术逐渐受到薄膜材料研究工作者的关注。然而，由于掠入射X射线散射的实验方法还不完整，理论分析较复杂，掠入射X射线散射的应用领域还十分有限。本论文主要的工作是在上海光源小角散射线站发展和完善掠入射X射线散射实验方法，并应用该技术研究自组装介孔薄膜和自组装聚电解质多层膜的微观结构，推动掠入射X射线散射技术在薄膜材料研究中的理论与实验发展。主要的工作内容如下： 1.发展和完善掠入射X射线散射实验方法。通过理论建模和实验分析相结合，建立了广角散射实验的角度校正方程，简化了校正过程。参与设计了小角散射线站首个掠入射原位控温装置，实现了真空或气氛环境下对薄膜温度变化过程的结构研究。开发了数据预处理平台，具备完整的数据预处理模块，解决了数据分析的格式不兼容问题，同时实现了对大批量数据的处理，提高了数据预处理的效率。 2.自组装介孔薄膜的微观结构和模板剂去除过程研究。建立了介孔薄膜的掠入射X射线散射模型，实现了对薄膜内部结构的半定量分析，可以获得内部介孔通道的尺寸分布、取向、通道排列规整程度等结构信息。应用模型对三种不同有序度的介孔薄膜的结构进行了表征，三种薄膜在结构上的主要差异表现为介孔通道偏离理想晶格位置的程度和介孔通道长度的分布。另外，模板剂去除过程的原位实验实现了秒时间分辨的薄膜微观结构观察，，薄膜内部的介孔通道在模板剂去除过程经历了先膨胀再收缩的过程，在这一过程中形成了局部缺陷，当介孔通道中的模板剂大量分解时，局部缺陷发展成区域性的结构混乱，薄膜有序度降低，而升温速率对介孔通道的形变量有着重要的影响，这些研究结果为优化薄膜制备工艺提供了指导。 3.自组装聚电解质多层膜的微观结构和生长机理研究。通过掠入射X射线散射、X射线反射率、原子力显微镜等技术观察了自组装不同阶段的结构变化，在薄膜生长初期观察到了表面有序结构，这可以归结为局部范围内聚电解质分子复合所形成，这些有序结构随着薄膜层数增加逐渐消失，这与分子间的融合和穿插密切相关。另外，在薄膜生长后期观察到了共振弥散散射，这为三区域结构模型提供了实验支持。共振弥散散射的临界尺寸与有序结构的尺寸相匹配，这表明有序的复合体可能是表面与内部结构传播的基本单元。因此，薄膜表面大于临界尺寸的结构是由靠近基底的结构所决定，而表面小于临界尺寸的结构主要与复合体内的分子构象相关。基于理论结构模型，论文模拟了二维散射图，模拟结果和实验结果基本相似，这为理论结构框架的准确性提供了依据。另外，本论文还应用掠入射散射技术对聚电解质薄膜热处理过程中结构演变进行了探索，为实现通过热处理方法实现薄膜结构调控提供了理论与实验指导。 本论文的工作内容以实验方法发展为起点，然后应用散射技术对薄膜结构进行了深入的研究，解决了结构分析中的重要问题，这对完善和推动掠入射X射线散射技术在自组装材料研究中的应用有着重要的借鉴意义。
[Abstract]:Grazing incidence X-ray scattering is one of the important means to characterize the structure of thin films. It has the advantages of nondestructive testing of samples and providing statistical information of large area surface structure. By combining grazing incidence X-ray scattering with synchrotron radiation source, in-situ structure evolution can be observed. Therefore, grazing incidence X-ray scattering technology is gradually thinned. However, the experimental methods of grazing incidence X-ray scattering are incomplete and the theoretical analysis is complicated, so the application fields of grazing incidence X-ray scattering are still very limited. The main work of this paper is to develop and improve the experimental methods of grazing incidence X-ray scattering at Shanghai Light Source Small Angle Scattering Line Station. The main work is as follows: 1. To study the microstructure of self-assembled mesoporous thin films and self-assembled polyelectrolyte multilayers, and to promote the theoretical and experimental development of grazing incidence X-ray scattering in thin film materials.
1. Developing and perfecting the experimental method of grazing incidence X-ray scattering. By combining theoretical modeling with experimental analysis, the angle correction equation of wide angle scattering experiment is established, and the correction process is simplified. The first grazing incidence in-situ temperature control device of small angle scattering line station is designed, which realizes the junction of temperature change process of thin film in vacuum or atmosphere. A data pre-processing platform is developed, which has a complete data pre-processing module, and solves the incompatibility of data analysis format. At the same time, it realizes the processing of a large number of data and improves the efficiency of data pre-processing.
2. Microstructure and template removal process of self-assembled mesoporous thin films were studied. Grazing incidence X-ray scattering model of mesoporous thin films was established. Semi-quantitative analysis of the internal structure of the films was realized. The size distribution, orientation and channel arrangement regularity of the internal mesoporous channels were obtained. The structure of mesoporous films was characterized by the degree of the deviation of mesoporous channels from the ideal lattice position and the distribution of the length of mesoporous channels. The removal process of the agent undergoes a process of expansion and shrinkage, in which local defects are formed. When a large number of templates are decomposed in the mesoporous channel, the local defects develop into regional structural disorder and the ordering degree of the film decreases. The heating rate has an important effect on the morphological variables of the mesoporous channel. These results are optimized. The film preparation process provides guidance.
3. Study on the microstructure and growth mechanism of self-assembled polyelectrolyte multilayers. The structural changes at different stages of self-assembly were observed by grazing incidence X-ray scattering, X-ray reflectance, atomic force microscopy and other techniques. The ordered surface structure was observed at the initial stage of film growth, which can be attributed to the local range of polyelectrolyte molecular recombination. As a result, these ordered structures gradually disappear with the increase of the number of layers, which is closely related to the intermolecular fusion and interpolation. In addition, resonance dispersion scattering was observed at the late growth stage of the films, which provides experimental support for the three-region structure model. The ordered complex may be the basic unit of surface-to-internal structure propagation. Therefore, the structure with a surface larger than the critical size is determined by the structure near the substrate, while the structure with a surface smaller than the critical size is mainly related to the molecular conformation in the complex. In addition, the grazing incidence scattering technique was used to investigate the structure evolution of polyelectrolyte films during heat treatment, which provides theoretical and experimental guidance for realizing the structure control of polyelectrolyte films by heat treatment.
In this paper, the experimental method is used as the starting point, and then the scattering technique is applied to study the structure of thin films. The important problems in structure analysis are solved. It is of great significance to perfect and promote the application of grazing incidence X-ray scattering technique in the study of self-assembled materials.
【学位授予单位】：中国科学院研究生院（上海应用物理研究所）
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.2
本文编号：2203003
[Abstract]:Grazing incidence X-ray scattering is one of the important means to characterize the structure of thin films. It has the advantages of nondestructive testing of samples and providing statistical information of large area surface structure. By combining grazing incidence X-ray scattering with synchrotron radiation source, in-situ structure evolution can be observed. Therefore, grazing incidence X-ray scattering technology is gradually thinned. However, the experimental methods of grazing incidence X-ray scattering are incomplete and the theoretical analysis is complicated, so the application fields of grazing incidence X-ray scattering are still very limited. The main work of this paper is to develop and improve the experimental methods of grazing incidence X-ray scattering at Shanghai Light Source Small Angle Scattering Line Station. The main work is as follows: 1. To study the microstructure of self-assembled mesoporous thin films and self-assembled polyelectrolyte multilayers, and to promote the theoretical and experimental development of grazing incidence X-ray scattering in thin film materials.
1. Developing and perfecting the experimental method of grazing incidence X-ray scattering. By combining theoretical modeling with experimental analysis, the angle correction equation of wide angle scattering experiment is established, and the correction process is simplified. The first grazing incidence in-situ temperature control device of small angle scattering line station is designed, which realizes the junction of temperature change process of thin film in vacuum or atmosphere. A data pre-processing platform is developed, which has a complete data pre-processing module, and solves the incompatibility of data analysis format. At the same time, it realizes the processing of a large number of data and improves the efficiency of data pre-processing.
2. Microstructure and template removal process of self-assembled mesoporous thin films were studied. Grazing incidence X-ray scattering model of mesoporous thin films was established. Semi-quantitative analysis of the internal structure of the films was realized. The size distribution, orientation and channel arrangement regularity of the internal mesoporous channels were obtained. The structure of mesoporous films was characterized by the degree of the deviation of mesoporous channels from the ideal lattice position and the distribution of the length of mesoporous channels. The removal process of the agent undergoes a process of expansion and shrinkage, in which local defects are formed. When a large number of templates are decomposed in the mesoporous channel, the local defects develop into regional structural disorder and the ordering degree of the film decreases. The heating rate has an important effect on the morphological variables of the mesoporous channel. These results are optimized. The film preparation process provides guidance.
3. Study on the microstructure and growth mechanism of self-assembled polyelectrolyte multilayers. The structural changes at different stages of self-assembly were observed by grazing incidence X-ray scattering, X-ray reflectance, atomic force microscopy and other techniques. The ordered surface structure was observed at the initial stage of film growth, which can be attributed to the local range of polyelectrolyte molecular recombination. As a result, these ordered structures gradually disappear with the increase of the number of layers, which is closely related to the intermolecular fusion and interpolation. In addition, resonance dispersion scattering was observed at the late growth stage of the films, which provides experimental support for the three-region structure model. The ordered complex may be the basic unit of surface-to-internal structure propagation. Therefore, the structure with a surface larger than the critical size is determined by the structure near the substrate, while the structure with a surface smaller than the critical size is mainly related to the molecular conformation in the complex. In addition, the grazing incidence scattering technique was used to investigate the structure evolution of polyelectrolyte films during heat treatment, which provides theoretical and experimental guidance for realizing the structure control of polyelectrolyte films by heat treatment.
In this paper, the experimental method is used as the starting point, and then the scattering technique is applied to study the structure of thin films. The important problems in structure analysis are solved. It is of great significance to perfect and promote the application of grazing incidence X-ray scattering technique in the study of self-assembled materials.
【学位授予单位】：中国科学院研究生院（上海应用物理研究所）
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.2
【参考文献】
相关期刊论文 前2条
1 苏彬;陆学民;路庆华;;定向介孔薄膜制备的研究进展[J];无机材料学报;2007年05期
2 李浩虎;余笑寒;何建华;;上海光源介绍[J];现代物理知识;2010年03期
本文编号：2203003
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