Spectroscopy with Nonimaging Optics: Application to the Infrared Spectroscopy of Langmuir Monolayers
- 1 May 1992
- journal article
- research article
- Published by SAGE Publications in Applied Spectroscopy
- Vol. 46 (5), 725-731
- https://doi.org/10.1366/0003702924124673
Abstract
We discuss the principles of nonimaging optics and demonstrate how nonimaging concentrators can be used to maximize the collection of low-intensity infrared light. Specifically, we show that infrared reflection-absorption spectra can be obtained from a Langmuir monolayer of heneicosanol with a reasonable number of scans. Preliminary results indicate that at 24 Å2/molecule and 6 dyne/cm a heneicosanol monolayer is in a crystalline phase with highly ordered, mostly all- trans molecules, and at 42 Å2/molecule and 0 dyne/cm the monolayer consists of islands of the crystalline phase in coexistence with disordered molecules in a liquid phase. The good signal-to-noise ratio of the spectra obtained demonstrates the important role that nonimaging optics has in spectroscopy, by maximizing light throughput, and we make several suggestions for its implementation in other spectroscopic applications.Keywords
This publication has 21 references indexed in Scilit:
- Infrared Emission Spectroscopy: A Theoretical and Experimental ReviewApplied Spectroscopy, 1991
- Effects of restricting the detector field of view when using integrating spheresApplied Optics, 1989
- Integrating sphere designs with isotropic throughputApplied Optics, 1989
- Design and Interfacing of an Automated Langmuir-Type Film Balance to an FT-IR SpectrometerApplied Spectroscopy, 1988
- In Situ Measurement of the FT-IR Spectra of Phospholipid Monolayers at the Air/Water InterfaceApplied Spectroscopy, 1988
- Reflectometer design using nonimaging opticsApplied Optics, 1987
- Quantitative external reflection infrared spectroscopic analysis of insoluble monolayers spread at the air-water interfaceThe Journal of Physical Chemistry, 1986
- Infrared spectra of crystalline n-alkanes. Changes observed during the phase I → phase II transitionCanadian Journal of Chemistry, 1983
- Modern infrared detectorsPhysics in Technology, 1973
- Solid state devices for infra-red detectionJournal of Scientific Instruments, 1966