Instrumental Techniques of Surface Chemistry

To explain how a machine works, designers refer to underlying causal mechanisms. In this context, a mechanism comprises a system of entities that is an agent for change, causally responsible for producing detectable effects. Consider the causal mechanisms underlying instrumental techniques of surface chemistry. 

In the surface analysis of polymeric materials it is rare that any one technique can completely characterize a surface. To some extent all surface analysis techniques have limitations that impose restrictions on the type of surface chemistry data they can generate. Therefore it is often necessary to combine information for different instruments to build a consistent characterization of surfaces. The complementary use of XPS and SSIMS provides an example of this approach. XPS data is often excellent at quantifying simple surface chemistry where either... 

Fourier transform infrared (FTIR) and in-situ FTIR spectroscopy are among many modern instrumental tools of analytical chemistry well established in fuel-cell-related electrochemistry [1]. In general, FTIR spectroscopy is a valuable tool in the characterization of fuel cell technical electrodes, where the nature of surface groups can be identified, since such electrodes are rather difficult solid surfaces on which to work. FTIR is among the methods less commonly used for the characterization of dispersed catalysts and supports, but as a technique is able to give an idea about the nature of the surface groups on carbon supports and on the structure of adsorbed species on noble metal clusters. 

Therefore, this book is to give the analyst - whether a newcomer wishing to acquaint themself with new methods or a materials analyst needing to inform themself on methods that are not available in their own laboratory - a clue about the principles, instrumentation, and applications of the methods, techniques, and procedures of surface and thin-film analysis. The first step into this direction was the chapter Surface and Thin Film Analysis of Ullmann s Encyclopedia of Industrial Chemistry (Vol. B6, Wiley-VCH, Weinheim 2002) in which practitioners give briefly outline the methods. 

Trends in mass spectrometry focus on the improvement of instrumentation, of several techniques in order to minimize sample volume, to improve sensitivity and to reduce detection limits. This is combined with increasing the speed of several analyses, with automation of analytical procedures and subsequently reducing the price of analysis. A minimizing of sample volumes means a reduction of waste volume with the aim of developing green chemistry . Furthermore, new analytical techniques involve a development of quantification procedures to improve the accuracy and precision of analytical data. Special attention in future will be given to the development of hyphenated mass spectrometric techniques for speciation analysis and of surface analytical techniques with improved lateral resolution in the nm scale range. 

Secondary Ion Mass Spectrometry used as a solo Instrument or in concert with other methods has proven to be an excellent technique for studying the surface chemistry of adhesive bonding materials. The application of SIMS is shown in re.lation to pretreatments of metals and alloys, chemistry and structure of adhesives, and locus of failure of debonded specimens. 

Despite its clever utility, SELDI suffers from several limitations. The SELDI MS instrumentation usually is capable of accurately detecting proteins with molecular weights less than 45,000, the detected proteins cannot be identified using this technique alone, and reproducibility in complicated experiments is suspect (86). Improvements in next-generation instruments using ProteinChip tandem MS techniques that enable direct protein identification (87), improved surface chemistries (88), and improved experimental design (89,90) should all greatly enhance SELDI s effectiveness as a powerful proteomic tool (91,92). 

Modern surface analytical tools make it possible to probe the physical structure as well as the chemical composition and reactivity of interfacial supramolecular assemblies with unprecedented precision and sensitivity. Therefore, Chapter 3 discusses the modern instrumental techniques used to probe the structure and reactivity of interfacial supramolecular assemblies. The discussion here is focused on techniques traditionally applied to the interrogation of interfaces, such as electrochemistry and scanning electron microscopy, as well as various microprobe techniques. In addition, some less common techniques, which will make an increasing contribution to supramolecular interfacial chemistry over the coming years, are considered. 

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