Interfaces, analysis

The external reflection of infrared radiation can be used to characterize the thickness and orientation of adsorbates on metal surfaces. Buontempo and Rice [153-155] have recently extended this technique to molecules at dielectric surfaces, including Langmuir monolayers at the air-water interface. Analysis of the dichroic ratio, the ratio of reflectivity parallel to the plane of incidence (p-polarization) to that perpendicular to it (.r-polarization) allows evaluation of the molecular orientation in terms of a tilt angle and rotation around the backbone [153]. An example of the p-polarized reflection spectrum for stearyl alcohol is shown in Fig. IV-13. Unfortunately, quantitative analysis of the experimental measurements of the antisymmetric CH2 stretch for heneicosanol [153,155] stearly alcohol [154] and tetracosanoic [156] monolayers is made difflcult by the scatter in the IR peak heights. 

Stoohr J, Ederer D L, Perera R C C, Tong W and Shunli D K 1995 Surface and interface analysis at 3rd generation light sources Prog. Surf Sci. 50 37-51... 

SURFACE AND INTERFACE ANALYSIS] (Supplement) [SURFACE AND INTERFACE ANALYSIS] (Supplement)... 

An introduction to several of the more common methods of surface and interface analysis has been presented in this article. This treatment is certainly not comprehensive. An ever-expanding number of methods for the interrogation of surfaces and interfaces are available to the analyst. The ones chosen for discussion here were meant to be representative of methods that can answer the more general questions posed at the beginning of this article. The reader is encouraged to pursue further reading on other techniques for specific appHcations in the many excellent monographs on the subject of surface and interface analysis. 

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