Secondary Ion Mass Spectrometry Methodology for Nanoparticles

在化学系化学测量和成像项目的支持下，德克萨斯州A M大学的Schweikert教授及其团队将开发一种用于分析单个纳米颗粒的创新方法。 NP的独特性，由于其功能不存在于批量大小，是有据可查的。 对其功能的细致入微的理解取决于其准确的特征描述。 通常，分析是在大量的NP（集合）上进行的。 然而，在NP群体中可能存在一些变化，并且系综平均可以限制对NP的大小、组成和化学反应性之间的关系的了解。 对于非常小的NP尤其如此，其中尺寸、形状和组成的微小变化可以显著影响化学反应性。 该研究涉及定制的仪器，并将专注于逐个探测非常小的NP（50纳米）。 简而言之，用400个金原子的单个簇轰击NP。 这种“纳米抛射体”以超高速（30公里/秒）撞击产生大量的离子发射，发射区域直径约为10纳米。 对每次撞击的喷出物进行质量分析并单独记录。 代表当前纳米材料研究的纳米颗粒将来自美国、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尺度材料的开发。

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.