Silver halide infrared fibre‐optic evanescent wave spectroscopy for in situ monitoring of the chemical processes in adhesive curing

A silver halide infrared fibre-optic evanescent wave spectroscopic technique for in situ monitoring of chemical processes and surface analysis is described. Attenuated total internal reflection (ATR) measurements with a Fourier transform infrared (FTIR) spectrometer allow spectra to be acquired at successive stages of chemical processes occurring within the surface layer. Samples are spread onto a fibre contained in a Teflon-lined cell, and may be maintained under appropriate conditions of temperature and atmosphere. Monitoring of adhesive curing and coupling agent polymerization is accomplished easily and changes in spectroscopic features may be recognized in films as thin as a monolayer. The advantages and limitations of this surface analysis technique are discussed.