Secondary Ion Mass Spectrometry Methodology for Nanoparticles

在化学系化学测量和成像项目的支持下，德克萨斯农工大学的Schweikert教授和他的团队将开发一种分析单个纳米粒子（NPs）的创新方法。NPs的独特性是由于它们的功能在批量大小中不存在，这是有充分记录的。对其功能的细致理解取决于它们的准确描述。一般来说，分析是在大量np（集合）上进行的。然而，NP种群中可能存在一些差异，集合平均可能会限制对NP大小、组成和化学反应性之间关系的了解。对于非常小的NPs尤其如此，其大小、形状和组成的微小变化会显著影响化学反应性。这项研究涉及定制的仪器，并将专注于一个接一个地探测非常小的纳米粒子（50纳米）。简而言之，NP被400个金原子组成的单个簇轰击。这种“纳米弹丸”以超高速（30公里/秒）撞击会在直径约10纳米的区域内产生大量离子发射。每次撞击产生的喷射物都要进行大规模分析和单独记录。代表当前纳米材料研究的NPs将来自美国、英国、法国和澳大利亚的实验室。研究纳米粒子的新工具将促进有效和安全的纳米材料的发展。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Schweikert at Texas A&M University and his group will develop an innovative methodology for the analysis of individual nanoparticles, NPs. The uniqueness of NPs, due to their functionalities not present in bulk size, is well documented. A nuanced understanding of their functionalities depends on their accurate characterization. Generally the analysis is done on a large number (ensemble) of NPs. However, there is likely some variation in the NP population and ensemble averaging can limit insight into the relationships between size, composition and chemical reactivity of NPs. This is especially the case for very small NPs, where minor changes in size, shape, and composition can significantly affect chemical reactivity. The research involves custom-built instrumentation and will focus on probing very small NPs ( 50 nanometers) one by one. Briefly, a NP is bombarded with an individual cluster of 400 gold atoms. The impact of such a "nanoprojectile" at hypervelocity (30 km/s) generates abundant ion emission from an area of ~10 nanometer in diameter. The ejecta from each impact are mass-analyzed and recorded individually. NPs representative of current nanomaterials research will come from laboratories in the US, UK, France and Australia. The new tools for investigating NPs will facilitate the development of efficacious and safe nano-scale materials.