Accession Number : AD0736332

Title :   Phase Transition Changes in Absorptivity of Simple Molecules in the Infrared.

Descriptive Note : Technical rept. Jul 70-Apr 71,

Corporate Author : EDGEWOOD ARSENAL MD

Personal Author(s) : Carlon,Hugh R.

Report Date : DEC 1971

Pagination or Media Count : 16

Abstract : Water and many other substances show marked increases in infrared absorptivity in the liquid phase when compared to the vapor phase. Absorptivity ratios generally increase with increasing wavelength. Quantitative liquid spectra are presented for water, acetone, diethyl ether, methanol, formic acid, acetic acid, and ethanol, from which absorptivity ratios for the liquid/vapor transition are calculated and tabulated. It is shown that extrapolation of spectral data between physical phases and meaningful study of vapor/aerosol mixtures in the infrared cannot be accomplished without an understanding of these phase transition effects. An obvious extension would be solid/liquid transition studies, particularly for ice effects in atmospheric investigations. (Author)

Descriptors :   (*PHASE STUDIES, *INFRARED SPECTRA), ABSORPTION SPECTRA, WATER, ACETONES, ETHERS, CARBINOLS, FORMIC ACID, ACETIC ACID, ETHANOLS, LIQUIDS

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE