“激光选择性表面气化”可控合成单分散胶体纳米晶

项目名称： “激光选择性表面气化”可控合成单分散胶体纳米晶

项目编号： No.51271129

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 杨静

作者单位： 天津大学

项目金额： 80万元

中文摘要： 单分散胶体纳米晶是组装先进功能纳米器件的理想单元,激光液相烧蚀法作为一种发展潜力巨大的常温、绿色、高效的纳米材料合成工艺，却仍存在纳米晶尺寸不均匀这一制约其发展的严重问题。虽然研究人员在"激光破碎"使贵金属纳米晶均匀细化方面已开展了一些工作，但由于尚缺少精巧而合理的设计，纳米晶尺寸均匀性仍不甚理想。本项目提出利用"激光选择性表面气化"，通过合理的设计，使被激光辐照的非均匀纳米晶只发生表面气化，尺寸逐渐减小且趋向均匀，最终达到略小于表面气化临界尺寸为止，纳米晶不再气化，形成单分散胶体纳米晶。本项目将利用这一普适思路可控制备各种金属、半导体单分散胶体纳米晶（尺寸分布<5%），阐明激光能量密度、溶剂和表面活性剂的介电常数对纳米晶均衡尺寸的调控作用，及脉冲激光辐照的非平衡条件下，表面气化纳米晶的变化规律。本项目将突破激光法在合成尺寸均匀纳米晶方面的瓶颈，为单分散胶体纳米晶的可控合成开辟一条新途径。

中文关键词： 激光烧蚀；单分散；胶体纳米晶；激光辐照；表面气化

英文摘要： Monodisperse colloidal nanocrystals have been considered as ideal building blocks for advanced functional nanodevices. As a green, efficient, and room-temperature synthesis technique, laser ablation in liquids (LAL) has been believed promising in nanomaterials synthesis, however, a wide size distribution of as-obtained nanocrystals remains one of the significant problems limiting LAL development. Although there have been some works on size-reduction/uniformity of noble metal nanocrystal via laser fragmentation, the uniformity of nanocrystals is still not good due to lack of elaborate designs. In this project, we take advantage of "selective-surface-evaporation by laser" to make reasonable designs, where the irradiated nonuniform nanocrystals are partially evaporated, thus reduced in size and tends to more uniform, and finally become monodisperse colloidal nanocrystals with a final average size slightly smaller than the critical size for surface-evaporation. By means of the above universal strategy, we will controllably synthesize a number of monodisperse colloidal metal and semiconductor nanocrystals with size dispersion less than 5%, clarify the effects of laser fluence, dielectric constants of liquid media and surfactants on the final average size of nanocrystals, and demonstrate the size evolution of partiall

英文关键词： laser ablation；monodisperse；colloidal nanocrystals；laser irradiation；surface evaporation