动力学可控合成Fe@Au纳米核壳结构的研究

The magnetic@noble metal core-shell nanoparticles(NPs) are a kind of versitle candidate which have many applications in the field of medical treatement, catalysis and nanodevice. The magnetic@noble metal core-shell nanoparticles(NPs) are very difficult to be synthesized due to the lack of theoritical direction since the traditional theory about colloidals' nucleation and growth tells nothing about this kind of bimetal core-shell system. Based on our preliminary work, this study aims at the preparation of Fe@Au NPs through injection of Au precursor into solution of as-prepared Fe NPs at a critical point of reaction. By studying how the kinetic parrameters such as temperature fluctuation affects the nucleation behavior of Au monomers, this study seeks to give a novel approach for the preparation of core-shell NPs of this kind, which can be used to control the morphology and structure of Fe@Au NPs. In this study, we are expected to deepen our understanding of the growth mechanism of magnetic@noble metal NPs.This study is also a meaningful reference to the study of core-shell structure of other systems.

双功能磁性金属@贵金属核壳结构的纳米颗粒在医疗，催化和纳米器件等领域有很好的应用前景。不过传统的关于纳米粒子成核生长的La Mer理论没有给出如何制备这种具有晶格高失配特点的核壳体系的理论指导。本项目旨在前期工作基础上进一步创新，通过在特定反应阶段时在含有Fe纳米粒子的溶液中注入金前驱体，然后控制温度急速上升和下降达到制备Fe@Au核壳纳米粒子的目标。通过研究温度的波动等动力学因素对金单体成核的抑制作用，本项目试图给出一种基于动力学控制思想指导的该类核壳纳米粒子制备的新途径；并运用该方法合成形貌可控，结构可调的Fe@Au多功能纳米核壳粒子。本研究不仅能加深对该体系纳米核壳结构生长机理的理解，同时对其它种类纳米结构的制备亦有重要的借鉴意义。

本项目对“磁性金属@贵金属核壳结构的制备”进行了大量实验研究和探索，主要的研究结果如下。首先针对现有的制备方法中少有结晶度较高的铁纳米颗粒报道的现状，采用高温连续注入的办法，利用无毒性的乙酰丙酮铁为前驱体，热分解法在315度得到高结晶的铁纳米粒子。其次，尝试对已有的结晶铁纳米粒子进行形貌调控的过程中发现卤素离子的加入在后期对小尺寸的无定型铁纳米粒子的熟化过程有显著影响，能促使无定型铁纳米粒子在更低的温度下发生结晶转变，从而可以获得更小，分散性更好的结晶铁纳米颗粒。进而，对已经制备的铁纳米粒子进行贵金属包覆，可以得到部分金包覆的复合纳米粒子。在复合材料的设计上主要集中在核心磁性金属的表面改性，从而实现对铁纳米粒子的包覆。本项目进行过程中发表SCI期刊收录论文7篇，获授权中国发明专利3篇，培养硕士毕业生3名。