Infrared continued transmission

TABLE 7.29 Infrared Transmission Characteristics of Selected Solvents Continued)... 

There are several major areas of interfacial phenomena to which infrared spectroscopy has been applied that are not treated extensively in this volume. Most of these areas have established bodies of literature of their own. In many of these areas, the replacement of dispersive spectrometers by FT instruments has resulted in continued improvement in sensitivity, and in the interpretation of phenomena at the molecular level. Among these areas are the characterization of polymer surfaces with ATR (127-129) and diffuse reflectance (130) sampling techniques transmission IR studies of the surfaces of powdered samples with adsorbed gases (131-136) alumina(137.138). silica (139). and catalyst (140) surfaces diffuse reflectance studies of organo- modified mineral and glass fiber surfaces (141-143) metal overlayer enhanced ATR (144) and spectroelectrochemistry (145-149). 

G. E. Ritchie and E. W. Ciurczak, Near-Infrared Transmission (NIT) Spectroscopy Assay of Continuous Release Prescription Analgesic Tablets, Proc. Eastern Analytical Symposium, Somerset, NJ, November, 1999. 

Fig. 15. Schematic representation of the time-resolved infrared (TRIR) flash photolysis apparatus used at Nottingham. The UV pulse laser generates transient species the continuous IR laser monitors the change in transmission at a particular IR frequency, producing a trace showing the IR absorbance as a function of time. The experiment is repeated at different IR frequencies so that a complete IR spectrum of the transient can be built up [reproduced with permission from (97), p. 103],...

Microtomed sections Sections of appropriate thickness for transmission infrared measurements may be microtomed from continuous solid samples. This presentation method is particularly useful for FT-IR microscopy. 

The author wishes to thank M. M. Fulk and R. H. Kropschot of the NBS-CEL for supplying the basic calorimeter design and for consultation on several occasions. H. Teicher and M. J. Scott of this laboratory have given continual counsel and assistance, and D. P. Ames and G. Brautigam have suggested the techniques adapted for infrared transmission measurements. 

X in PDAs and are of continuing interest. However, poly-PTS crystals grown to date do not have optically flat surfaces, and their study has been facilitated by immersion in diiomethane, which has a refractive index comparable to the polymer in the near infrared region (13). Thin polycrystalline films of poly-PTS (16) do not improve the situation in that they have significant transmission losses in the near infrared (17). 

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