Static FTIR technique

Both a conservative rapid-scan FTIR technique and a novel step-scan FTIR technique with two-dimensional analysis were used to study the orientation and the mobility of a ferroelectric liquid crystal dimer during switching under an electric field. The detailed mutual arrangements of different molecular segments (mesogen, poly(methylene) chain, polysiloxane chain) in a smectic C phase were derived from the static spectra. Temperature and electric field strength dependencies of the mobility of these segments are discussed. 18 refs. 

The problem with sulfide catalysts (hydrotreatment) is to determine the active centres, which represent only part of their total surface area. Chemisorption of O2, CO and NO is used, and some attempts concern NIL, pyridine and thiophene. Static volumetric methods or dynamic methods (pulse or frontal mode) may be used, but the techniques do not seem yet reliable, due to the possible modification (oxidation) of the surface or subsurface regions by O2 or NO probe molecules or the kinetics of adsorption. CO might be more promising. Infrared spectroscopy, especially FTIR seems necessary to characterise co-ordinativcly unsaturated sites, which are essential for catalytic activity. CO and NO can also be used to identify the chemical nature of sites (sulfided, partially reduced or reduced sites). For such... 

FTIR microspectroscopy has made remarkable progress in understanding multi-component polymer systems. A range of issues - from static morphology to sub-molecular molecular dynamics can now be analyzed by the versatile set of tools this technique affords. The last 5-10 years have been a period of intense development on both instrumental and data interpretation fronts. For applications to pol-... 

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