EFFECT OF INFRARED RADIATION AND AIR-FLOW ON FOURIER-TRANSFORM INFRARED EXTERNAL REFLECTION SPECTRA OF LANGMUIR MONOLAYERS

Effect of infrared radiation (heat ray) on FT-IR external reflection s pectra of Langmuir monolayers (L films) was examined in detail by chan ging the amount of radiation energy with an inserted optical aperture and a band path filter to cut off the heat ray. If the radiation energ y at the level of normal FT-IR measurements was used, the external ref lection spectra of the L films of stearic acid at large surface areas could not be observed, owing to the temperature increase in the irradi ated region and the enormous surface density decrease which follows it . In this connection, the effect of wind (air flow) on the same measur ements was also examined and discussed.