【作者】 王志栋；

【导师】 徐自力；

【作者基本信息】 北京化工大学 ， 材料学， 2007， 硕士

【摘要】 Ⅱ-Ⅵ族半导体纳米粒子是一种重要的光电功能材料，引起了人们的广泛关注，并产生了各种制备方法。通过使用聚乙烯烷酮(PVP)、聚苯乙烯-顺丁烯二酸酐(PSM)作为分散剂，在水溶液中制备了CdS纳米晶体；制备水溶性半导体CdSe纳米晶体，并且利用反相微乳液法对制备所得的CdSe纳米晶体进行了包覆和封装。采用AFM(原子力显微镜)和TEM(透射电镜)表征纳米粒子的形貌；使用XRD(X射线衍射)测试纳米粒子的结构；使用Uv-vis(紫外可见光谱)、PL(荧光光谱)考察了纳米粒子的光学性能。通过FT-IR(红外光谱)推测粒子与聚合物之间可能的作用力。结果显示：1．在PVP存在下，通过控制反应体系的pH值和分散剂的浓度和温度等因素，实现了CdS纳米微粒从球形向棒状的转变。制备的球形纳米粒子具有良好的形貌和粒子分布，并且探讨了巯基乙酸作为修饰剂时，对CdS纳米晶体光致发光性能的影响。2．采用PSM共聚物作为模板，制备的CdS纳米粒子粒径更小且分布更加均匀，显示酸酐官能团对纳米粒子具有良好的固定吸附作用，结果显示在碱性条件下，CdS纳米晶体的光致发光性能更好。3．使用巯基乙酸作为表面修饰剂，制备水溶性CdSe纳米晶体，研究其粒子大小和分布及其光学性质。4．使用反相微乳液法，在反相水核内合成PAM，使其包覆在CdSe纳米表面，制备CdSe／PAM核壳纳米粒子。电镜结果显示制备所得的复合纳米粒子的粒径在70nm左右。更多还原

【Abstract】 As a kind of very important photoelectric material, CdS and CdSe nanoparticles have drawn more attention recently. Because of its potential applications, a variety of synthesis schemes have been developed.In the dissertation, CdS nanocrystals were prepared in aqueous solution with water-soluble polymer PVP(polyvinylpyrrolidone) and PSM(styrene-maleic anhydride copolymer) as stabilizer. Besides, water soluble CdSe nanocrystals were coated with PAM(polyacrylamide) by w/o microemulsion. AFM and TEM were utilized to study the morphology shape. The structure was characterized by means of XRD. Uv-vis and PL spectra were used to study optical property. Finally, FT-IR was utilized to study the interaction between polymers and nanocrystals.1. In the presence of PVP, it was found that through adjusting the pH values of aqueous solution or PVP concentrations, the morphology of CdS nanoparticles would be transformed from spherical to clubbed shape. Spherical CdS nanopartilces have good shape and size distribution. Furthermore, the effect of thioacetic acid on the optical property of CdS nanoparticles was discussed.2. Using PSM copolymer as template, CdS nanoparticles got by this method show smaller particle size and more well-proportioned size distribution. The result indicates that there are some interaction between CdS and maleic anhydride, and CdS/polymer nanocrystal composites were very stable and gave much brighter photoluminescence when the solution is in big pH value.3. Using thioacetic acid as surface modifier, water soluble CdSe nanocrystals were made in aqueous solution. Size and size distribution and optical properties of CdSe nanocrystals were also studied in this chapter for next coating.4. By using w/o emulsion system, CdSe nanoparticles were encapsulated by PAM which meanwhile was polymerized with AM monomer in water droplet. AFM indicated that core/shell CdSe/PAM nanoparticle composites have the diameter about 70nm.更多还原