X射线小角散射系统构造及应用研究

Construction and application study of X-ray small-angle scattering system

X射线小角散射(SAXS)是研究介观尺度固态或液态结构的有力工具。由于SAXS有关理论和解析方法还不成熟,用于专门测试小角特性的仪器"X射线小角散射系统"发展远不如其他X射线衍射仪,而且还不为广泛了解和利用,仪器构造分析及软件也很少有人介绍。介绍了小角散射的原理及构造;探讨了影响测试结果的因素,如:光源、光路系统、分辨率、样品的厚度、探测器等。通过4个基于SAXS的应用研究实例开发了仪器的功能。以SBA-15为例,分析了如何通过该系统表征确定有序介观材料的结构;表征了取向碳纳米管/液晶高分子复合材料的结构;通过SAXS原位变温测试表征了二炔酸/三聚氰胺胶束固体的结构特征;利用SAXS确定了线性聚乙烯退火前后长周期的变化。最后,本文详细的介绍了目前仪器测试功能的局限性和硬件升级改造。

X-ray small-angle scattering （SAXS） is a powerful tool in research of solid or liquid structure at meso- scopic scale. For a long time, the SAXS theory and analytic methods were not mature and the instruments on SAXS were less developed compared with other X-ray diffraction （XRD） instruments. As a result, SAXS was not well understood and utilized, and the instrument structure and software were rarely introduced. The principle and the characteristics of SAXS were described in this paper. The factors that affect on the test result, such as light source, optical system, resolution, sample thickness, and the detector were discussed. Furthermore, this paper explored the SAXS instrument by four examples of applied research ： 1 ） analysis of ordered mesoscopic structure of SBA-15 by SAXS ; 2 ） characterization of carbon nanotube / liquid crystalline polymers composite structure ; 3 ） characterization of the diacetylenic acid / melamine micelle solid by in-situ temperature SAXS; 4） determination of the long cycle change of linear polyethylene before and after annealing by SAXS. Finally, the limitations of this instrument and possible upgrade of the hardware were introduced in details.