SAXS/WAXS for monitoring structure evolution in ultranarrow alkylamine-coated ZnS nanoparticle suspensions

We aim to investigate the structure evolution in suspensions of ultranarrow, monodispersed ZnS nanowires and nanorods in different solvents and concentrations. The hierarchical structure in this system starts from the atomic level structure of the Zn and S ions, through the molecular level structuring of their surfactant coating, and finally to the ‘artificial crystals’ formed by the nanoparticle assemblies. In addition to static measurements, dynamic SAXS/WAXS ‘snapshots’ of select nanoparticle suspensions will be taken under shear flow. The SAXS/WAXS setup combined with the shear cell at ID-02 is particularly suited for the above studies with d-spacing values ranging from few Ångstroms (atomic scale) to the order of several nm. The ultimate goal of the experiment is to correlate the hierarchical structure obtained from SAXS/WAXS measurements with the optical properties (photoluminescence and optical absorption spectroscopy in the UV-vis) of the ZnS nanoparticle assemblies.

本研究旨在探究不同溶剂与浓度条件下，超窄单分散硫化锌(ZnS)纳米线与纳米棒悬浮体系的结构演化过程。该体系的层级结构始于锌与硫离子的原子级结构，经由其表面活性剂包覆层的分子级结构化过程，最终形成由纳米颗粒组装体构成的“人工晶体”。除静态测量外，本研究还将在剪切流条件下采集选定纳米颗粒悬浮体系的动态小角X射线散射/广角X射线散射(SAXS/WAXS)“快照”。依托ID-02线站的剪切池与SAXS/WAXS探测装置联用系统，可精准覆盖从数埃(Å)（原子尺度）至数纳米量级的面间距范围，尤其适配上述研究需求。本实验的终极目标是将通过SAXS/WAXS测量得到的层级结构，与硫化锌(ZnS)纳米颗粒组装体的光学特性（紫外-可见(UV-vis)波段下的光致发光与光吸收光谱）建立关联。