Laser Raman Studies Related to Liquid Propellants: Structural Characteristics Inferred from the Nitrate Anion Spectra.
Abstract
Experimental Raman studies on aqueous hydroxylammonium nitrate (HAN) show concentration dependent center frequency and linewidth changes of the NO3 vibrations which are similar to the aqueous alkali-metal nitrates; but not ammonium nitrate. Comparison of Raman spectra for HAN and silver nitrate dissolved in both water an acetonitrile demonstrate there is no substantial contact-ion pairing for aqueous HAN solutions at concentrations around 0.2 M. Markedly decreased linewidths and band splittings occur when HAN is solidified. The center frequency of the Raman bands have been observed to be temperature dependent. From-50 C to 22 C, the NU4 band center frequency decreases by about 4/cm; however, no discernible temperature dependent asymmetries were detected. A laser induced fluorescence signal originating from some impurity has been observed during the course of these experiments on aqueous HAN. This impurity has a broad, structureless, visible absorption spectrum and tests are negative for being of microbe origin. Keywords: Laser Raman spectroscopy, Nitrate anion, Liquid propellants.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1987
- Accession Number
- ADA188462
Entities
People
- John A. Vanderhoff
- Philip M. Donmoyer
- Steven W. Bunte
Organizations
- Ballistic Research Laboratory