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首页> 外文学位 >Time-of-flight static secondary ion mass spectrometry as an analytical tool to obtain molecular information on and in organic materials.
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Time-of-flight static secondary ion mass spectrometry as an analytical tool to obtain molecular information on and in organic materials.

机译：飞行时间静态次级离子质谱分析法作为一种分析工具，可获取有机材料及其上的分子信息。

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摘要

The fast progress in material and human science puts high demands on analytical techniques. To fully understand the working principles of materials, detailed structural information on a small scale (nm), is often needed. In this work a methodology is developed which uses time-of-flight static secondary ion mass spectrometry (TOF-S-SIMS) to obtain molecular information on and in organic materials with a lateral resolution below 1 mum. Two important issues are addressed, the optimization of sample preparation methods and the enhancement of secondary ion yields.; In first instance a series of organic fluorinated carbocyanine dyes, containing cationic, anionic and zwitterionic dyes with similar structures, and the pharmaceutical Risperidone were measured with different primary ion guns (Ga+, SF5+, Aun +), on different substrates (Si, Ag, PET,...) and embedded in several polymer matrices, in order to get more insight on their behaviour under primary ion bombardment. By using the desorption-ionisation model (DI) it was possible to produce tentative fragmentation pathways and assign the most important ion signals in the recorded spectra with a mass accuracy of at least 50 ppm.; TOF-S-SIMS is a surface sensitive technique, so to obtain data of the deeper layers, a suitable sample preparation technique is needed. In this context several methods were tested, laserablation, cross section polisher (CSP), glow discharge, microtomy and focused ion beam milling (FIB).; Organic molecules generally give low secondary ion yields when measured with TOF-S-SIMS, so a method is needed that can induce an enhancement of the organic ion yields. Two methods were studied in this regard, namely, matrix-enhanced SIMS (ME-SIMS) and metal-assisted SIMS (MetA-SIMS). In ME-SIMS the analyte is mixed with a suitable MALDI matrix which resulted in enhancement factors between 4 and 45. For the MetA-SIMS method a thin layer (3-5 nm) of noble metals (Au, Ag) is deposited onto the sample surface prior to the measurement. This gives rise to enhancement factors of 100 and more.; The knowledge, obtained during sample preparation experiments and MetA-SIMS experiments was combined to do some measurements in cross sections of organic materials consisting of one or more layers.
机译：物质科学和人类科学的飞速发展对分析技术提出了很高的要求。为了充分理解材料的工作原理，通常需要小规模（nm）的详细结构信息。在这项工作中，开发了一种方法，该方法使用飞行时间静态二次离子质谱（TOF-S-SIMS）获得横向分辨率低于1微米的有机材料及其上的分子信息。解决了两个重要问题，即样品制备方法的优化和次级离子产率的提高。首先，使用不同的主离子枪（Ga +，SF5 +，Aun +）在不同的基质（Si，Ag， PET，...）并嵌入到几种聚合物基质中，以更深入地了解它们在一次离子轰击下的行为。通过使用解吸电离模型（DI），可以产生初步的碎片化途径，并以至少50 ppm的质量准确度分配记录的光谱中最重要的离子信号。 TOF-S-SIMS是一种表面敏感技术，因此要获得更深层的数据，需要一种合适的样品制备技术。在这种情况下，测试了几种方法，包括激光烧蚀，截面抛光器（CSP），辉光放电，切片机和聚焦离子束铣削（FIB）。当用TOF-S-SIMS测量时，有机分子通常会产生较低的次级离子产率，因此需要一种可以提高有机离子产率的方法。在这方面研究了两种方法，即基质增强SIMS（ME-SIMS）和金属辅助SIMS（MetA-SIMS）。在ME-SIMS中，将分析物与合适的MALDI基质混合，导致增强因子在4至45之间。对于MetA-SIMS方法，将一层薄薄的（3-5 nm）贵金属（Au，Ag）沉积在金属上。测量之前的样品表面。这将导致增强因子达到100或更高。结合样品制备实验和MetA-SIMS实验获得的知识，对由一层或多层组成的有机材料的横截面进行一些测量。

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  • 作者

    Adriaensen, Lesley.;

  • 作者单位

    Universiteit Antwerpen (Belgium).;

  • 授予单位 Universiteit Antwerpen (Belgium).;
  • 学科 Chemistry Analytical.
  • 学位 Ph.D.
  • 年度 2006
  • 页码 179 p.
  • 总页数 179
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 化学;
  • 关键词

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