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对半导体纳米粒子的表面修饰不仅可以获得稳定和具有良好分散性的体系,而且可以通过表面修饰分子与粒子表面的相互作用来控制其线性和非线性光学过程。利用胶体法和微乳液法合成CdS纳米粒子的水溶胶和有机溶胶,通过控制粒子表面富Cd~(2+),从而实现与有机配体的复合。系统研究了吡啶、2,2’-联吡啶、1.10-邻菲咯啉等有机配体对CdS水溶胶合成的影响,包括稳定性、尺寸控制、粒径分布等方面的探讨。用微乳液法合成了表面包覆表面活性剂的CdS纳米粒子有机溶胶,通过表面替换反应成功实现了用吡啶、2,2’-联吡啶对CdS纳米粒子的表面修饰,获得了一种表面包覆电中性配体同时带有表面活性剂阴离子作为平衡电荷的复合粒子体系;进而成功实现了用阴离子BPh_4~-对表面活性剂阴离子的替换,得到了一种类强电解质结构的纳米粒子。 研究了用微乳液法合成的、表面分别包覆表面活性剂、吡啶、2,2’-联吡啶的CdS纳米粒子的荧光性质和光解行为,发现含N杂环类分子能够强烈地猝灭CdS纳米粒子的荧光,并且用电荷转移猝灭机制成功地进行了解释。重点研究了表面修饰对纳米粒子二阶、三阶光学非线性的影响。二阶、三阶极化率的测量分别在超瑞利散射装置、简并四波混频装置上进行。纳米粒子二阶非线性的研究,属刚刚开始的阶段,其具体的
Surface modification of semiconductor nanoparticles not only achieves stable and well-dispersed systems, but also controls their linear and nonlinear optical processes through the interaction of surface-modified molecules with the particle surface. The colloidal and microemulsion methods were used to synthesize the hydrosol and organosol of CdS nanoparticles, and the complexation with organic ligands was achieved by controlling the Cd2 + -concentration on the particle surface. The effects of organic ligands such as pyridine, 2,2’-bipyridine and 1.10-phenanthroline on the synthesis of CdS hydrosol were systematically investigated, including stability, size control and particle size distribution. Surface-coated CdS nanoparticle organic sol with surfactant was synthesized by microemulsion method. The surface modification of CdS nanoparticle with pyridine and 2,2’-bipyridyl was successfully achieved by surface substitution reaction. A surface coated The coated neutral ligands have surfactant anions as the balanced charge composite particle system. The successful replacement of the anionic surfactants by the anion BPh_4 ~ - has been proved to be a kind of nanoparticle with strong electrolyte structure. The fluorescence properties and photolysis behaviors of CdS nanoparticles synthesized by microemulsion method and coated with surfactant, pyridine and 2,2’-bipyridine respectively were studied. It was found that N-containing heterocyclic molecules could strongly quench CdS Fluorescence of nanoparticles, and was successfully explained by the charge-transfer quenching mechanism. The effects of surface modification on the second-order and third-order optical nonlinearity of nanoparticles are mainly studied. Second-order, third-order polarizability measurements were performed on a Rayleigh scattering device, a degenerated four-wave mixing device, respectively. The second-order nonlinearity of nanoparticle research is at the beginning of its phase, its specific