三元添加剂水溶液体系合成亚微米硫化锌空心球

Synthesis of ZnS Hollow Submicrometer Spheres in an Aqueous Ternary-additive System

利用仿生合成方法 ,通过加入一定量的引发剂使甲基丙烯酸原位聚合 ,在聚乙二醇 (PEG)、聚甲基丙烯酸 (PMAA)和十二烷基硫酸钠 (SDS)的三元添加剂混合溶液体系中控制了合成硫化锌晶体 ,提出了一种简单易行的合成硫化锌空心球的新方法 .采用透射电子显微镜 (TEM)、扫描电子显微镜 (SEM)、X射线粉末衍射 (XRD)及紫外吸收光谱等手段对合成样品的形貌、结构及性能进行了表征 .TEM结果显示 ,Zn S空心球的直径约为 3 0 0～ 40 0 nm,其壳层的厚度约为 5 0 nm. SEM结果显示 ,空心球的外壳是由初级纳米粒子定向熔合排列形成的蠕虫状结构紧密组装而成 .由于相应的胶束结构的改变 ,表面活性剂 SDS浓度的变化明显改变了 Zn S产物的形貌 ,在较高浓度的 SDS溶液中得到了 Zn S片状晶体的球形聚集体 .利用核 -壳机理初步解释了空心球结构的形成过程 .

In this paper, it is demonstrated that the utility of poly-(ethylene glycol)(PEG), methacrylic acid(MAA) and sodium dodecylsulfate(SDS) can exert an exceptional control on the crystallization of ZnS by the in-situ polymerization of MAA monomers through addition of a certain amount of initiator, hereby provide a facile synthesis route to hollow ZnS spheres. The products obtained were characterized by using X-ray diffraction(XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM), and UV-Vis optical absorption. TEM studies suggest that the hollow spheres with diameters ranging from 300 to 400 nm are obtained. The wall thickness was estimated to be about 50 nm. SEM images show that the wall is constituted of compact worm-like structures, which consist of well-aligned primary nanoparticles. It was also found that the variation of surfactant concentration drastically changed the morphology of the produced ZnS products due to the corresponding transformation of micelles′ structure. At a relative higher SDS concentration, ZnS spherical assemblies of platelike crystallites were obtained. The formation of the hollow spherical structure was interpreted in terms of the core-shell mechanism.