FT-IR External Reflection Spectroscopy Study on Photochromic Monolayers at the AirWater Interface

Photoresponse behavior of azobenzene containing fatty acid in Langmuir (L) film was investigated using FT-IR and UV-vis spectra. Irradiation of UV or visible light resulted in reversible photoisomerizadon of the fatty acid in L film. The orientational change in the alkyl chain of the fatty acid in L film was determined in situ by FT-IR external reflection spectra, and the effect of the surface area on these changes is discussed.