A method is described that enables the alternated total reflectance infrared (ATR-IR) spectroscopy of thin-layer samples deposited onto one side of an exchangeable silicon wafer, the uncoated side of which is pressed against a small-area diamond single-reflection element. The pressing device is designed as a hollow spindle with a small ring-shaped opening at the end facing the wafer; thus, the sample spot involved in the measurement remains undisturbed. The sample can be UV-irradiated, and the atmosphere above it can be flushed with an inert gas introduced through the hollow spindle. The performance of the method is illustrated by the investigation of the influence of pressing force on background and on absorption band areas. With a commercial real-time Fourier transform infrared (FT-IR) spectrometer, the measurement of the UV-polymerization kinetics following the vanishing of the double bounds is demonstrated for a few thin-layer samples that were deposited on silicon wafers by spin-coating or by the Langmuir-Blodgett technique.
G. Muller and C. Riedel, "Real-Time ATR-IR Spectroscopy of Samples on Exchangeable Composite Reflection Elements," Appl. Spectrosc. 53, 1551-1555 (1999)