Formation and growth of copper nanoparticles from ion-doped precursor polyimide layers
Formation and growth of copper nanoparticles from ion-doped precursor polyimide layers
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DOI：
10.1021/jp0478559
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发表时间：
2004-10-07
影响因子：
3.3
通讯作者：
Deki, S
中科院分区：
文献类型：
--
作者：
Ikeda, S;Akamatsu, K;Deki, S
研究了由聚酰亚胺薄层和不同尺寸(直径3-10 nm)的铜纳米颗粒组成的杂化纳米复合材料的形成过程。在该系统中，在化学修饰的聚酰亚胺基质中完全或适度掺杂铜离子的前驱体层在氢气气氛中以恒定的加热速度进行退火热处理。用电感耦合等离子体原子发射光谱和傅里叶变换红外光谱分别表征了掺杂铜离子的还原行为和基质膜化学结构的变化。结果表明，还原形成铜纳米粒子的过程与形成杂环酰亚胺环的基质的脱水反应(再亚胺化)之间存在很强的相关性，这取决于铜离子的初始负载。用透射电子显微镜和纳米束能谱分析相结合的方法观察到，在较高的温度下热处理后，初始形成了铜团簇和纳米颗粒，进一步的退火导致了较大的单分散颗粒的生长，这可以归因于以团簇和较小的颗粒为代价的扩散控制的聚集生长。这些实验为基于这些离子掺杂前驱体树脂的杂化纳米复合材料的微观结构调整提供了重要的启示。
A study aimed at investigating the process of formation of hybrid nanocomposites consisting of a thin polyimide layer containing copper nanoparticles of varying sizes (3-10 nm in diameter) is described. In this system, precursor layers in which copper ions are fully or modestly doped in a chemically modified polyimide matrix are annealed in a hydrogen atmosphere at a constant heating rate. Reduction behavior of doped copper ions and changes in the chemical structure of the matrix film were characterized by inductively coupled plasma atomic emission spectroscopy and Fourier transform infrared spectroscopy, respectively. The results revealed that there is a strong correlation between both the process of reduction to form copper nanoparticles and the dehydration reaction of the matrix that forms heterocyclic imide rings (re-imidization), depending on the initial loading of copper ions. Transmission electron microscopy coupled with nanobeam energy-dispersive X-ray analysis was utilized to observe that upon annealing at a relatively high temperature, copper clusters and nanoparticles are initially formed, and further annealing lead to growth of larger monodispersed particles, which could be attributed to diffusion-controlled aggregative growth at the expense of clusters and smaller particles. These experiments provided important implications for the microstructural tuning of the hybrid nanocomposites based on approaches using these ion-doped precursor resins.