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Title: Time-resolved infrared reflectance studies of the dehydration-induced transformation of uranyl nitrate hexahydrate to the trihydrate form

Abstract

Uranyl nitrate is a key species in the nuclear fuel cycle. However, this species is known to exist in different states of hydration, including the hexahydrate ([UO2(NO3)2(H2O)6] often called UNH), the trihydrate [UO2(NO3)2(H2O)3 or UNT], and in very dry environments the dihydrate form [UO2(NO3)2(H2O)2]. Their relative stabilities depend on both water vapor pressure and temperature. In the 1950s and 1960s, the different phases were studied by infrared transmission spectroscopy but were limited both by instrumental resolution and by the ability to prepare the samples for transmission. We have revisited this problem using time-resolved reflectance spectroscopy, which requires no sample preparation and allows dynamic analysis while the sample is exposed to a flow of N2 gas. Samples of known hydration state were prepared and confirmed via X-ray diffraction patterns of known species. In reflectance mode the hexahydrate UO2(NO3)2(H2O)6 has a distinct uranyl asymmetric stretch band at 949.0 cm–1 that shifts to shorter wavelengths and broadens as the sample desiccates and recrystallizes to the trihydrate, first as a shoulder growing in on the blue edge but ultimately results in a doublet band with reflectance peaks at 966 and 957 cm–1. The data are consistent with transformation from UNH to UNT as UNTmore » has two inequivalent UO22+ sites. The dehydration of UO2(NO3)2(H2O)6 to UO2(NO3)2(H2O)3 is both a structural and morphological change that has the lustrous lime green UO2(NO3)2(H2O)6 crystals changing to the matte greenish yellow of the trihydrate solid. As a result, the phase transformation and crystal structures were confirmed by density functional theory calculations and optical microscopy methods, both of which showed a transformation with two distinct sites for the uranyl cation in the trihydrate, with only one in the hexahydrate.« less

Authors:
 [1];  [1];  [1];  [2];  [3];  [1]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. Univ. of Nevada, Las Vegas, NV (United States)
  3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1236243
Report Number(s):
SAND-2015-5290J
Journal ID: ISSN 1089-5639; 594533
Grant/Contract Number:  
AC04-94AL85000
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
Additional Journal Information:
Journal Volume: 119; Journal Issue: 39; Journal ID: ISSN 1089-5639
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; 36 MATERIALS SCIENCE

Citation Formats

Johnson, Timothy J., Sweet, Lucas E., Meier, David E., Edward J. Mausolf, Kim, Eunja, Weck, Philippe F., Buck, Edgar C., and Bruce K. McNamara. Time-resolved infrared reflectance studies of the dehydration-induced transformation of uranyl nitrate hexahydrate to the trihydrate form. United States: N. p., 2015. Web. doi:10.1021/acs.jpca.5b06365.
Johnson, Timothy J., Sweet, Lucas E., Meier, David E., Edward J. Mausolf, Kim, Eunja, Weck, Philippe F., Buck, Edgar C., & Bruce K. McNamara. Time-resolved infrared reflectance studies of the dehydration-induced transformation of uranyl nitrate hexahydrate to the trihydrate form. United States. https://doi.org/10.1021/acs.jpca.5b06365
Johnson, Timothy J., Sweet, Lucas E., Meier, David E., Edward J. Mausolf, Kim, Eunja, Weck, Philippe F., Buck, Edgar C., and Bruce K. McNamara. 2015. "Time-resolved infrared reflectance studies of the dehydration-induced transformation of uranyl nitrate hexahydrate to the trihydrate form". United States. https://doi.org/10.1021/acs.jpca.5b06365. https://www.osti.gov/servlets/purl/1236243.
@article{osti_1236243,
title = {Time-resolved infrared reflectance studies of the dehydration-induced transformation of uranyl nitrate hexahydrate to the trihydrate form},
author = {Johnson, Timothy J. and Sweet, Lucas E. and Meier, David E. and Edward J. Mausolf and Kim, Eunja and Weck, Philippe F. and Buck, Edgar C. and Bruce K. McNamara},
abstractNote = {Uranyl nitrate is a key species in the nuclear fuel cycle. However, this species is known to exist in different states of hydration, including the hexahydrate ([UO2(NO3)2(H2O)6] often called UNH), the trihydrate [UO2(NO3)2(H2O)3 or UNT], and in very dry environments the dihydrate form [UO2(NO3)2(H2O)2]. Their relative stabilities depend on both water vapor pressure and temperature. In the 1950s and 1960s, the different phases were studied by infrared transmission spectroscopy but were limited both by instrumental resolution and by the ability to prepare the samples for transmission. We have revisited this problem using time-resolved reflectance spectroscopy, which requires no sample preparation and allows dynamic analysis while the sample is exposed to a flow of N2 gas. Samples of known hydration state were prepared and confirmed via X-ray diffraction patterns of known species. In reflectance mode the hexahydrate UO2(NO3)2(H2O)6 has a distinct uranyl asymmetric stretch band at 949.0 cm–1 that shifts to shorter wavelengths and broadens as the sample desiccates and recrystallizes to the trihydrate, first as a shoulder growing in on the blue edge but ultimately results in a doublet band with reflectance peaks at 966 and 957 cm–1. The data are consistent with transformation from UNH to UNT as UNT has two inequivalent UO22+ sites. The dehydration of UO2(NO3)2(H2O)6 to UO2(NO3)2(H2O)3 is both a structural and morphological change that has the lustrous lime green UO2(NO3)2(H2O)6 crystals changing to the matte greenish yellow of the trihydrate solid. As a result, the phase transformation and crystal structures were confirmed by density functional theory calculations and optical microscopy methods, both of which showed a transformation with two distinct sites for the uranyl cation in the trihydrate, with only one in the hexahydrate.},
doi = {10.1021/acs.jpca.5b06365},
url = {https://www.osti.gov/biblio/1236243}, journal = {Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory},
issn = {1089-5639},
number = 39,
volume = 119,
place = {United States},
year = {Tue Sep 08 00:00:00 EDT 2015},
month = {Tue Sep 08 00:00:00 EDT 2015}
}

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Works referenced in this record:

Quantitative reflectance spectra of solid powders as a function of particle size
journal, January 2015


Reflectance spectra of regolith analogs in the mid-infrared: effects of grain size
journal, April 2003


Gas-Phase Hydrolysis of SOCl 2 at 297 and 309 K:  Implications for Its Atmospheric Fate
journal, August 2003


Bond orientations in uranyl nitrate hexahydrate using attenuated total reflection
journal, July 1966


The Raman Scattering of Uranyl and Transuranium V, VI, and VII Ions
journal, March 1974


The experimental study of the rate of dissociation of salt hydrates. The reaction CuSO4.5H2O = CuSO4.H2O + 4H2O
journal, November 1931

  • Smith, M. L.; Topley, B.
  • Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, Vol. 134, Issue 823, p. 224-245
  • https://doi.org/10.1098/rspa.1931.0193

Infra-Red Spectra of Uranyl Compounds. I. Uranyl Nitrates
journal, January 1959


Uranium-Oxygen Bond Lengths in Uranyl Salts: Uranyl Fluoride and Uranyl Carbonate.
journal, June 1963


802. Infrared spectra of uranyl nitrate hydrates and rubidium uranyl nitrate
journal, January 1958


Structures of uranyl peroxide hydrates: a first-principles study of studtite and metastudtite
journal, January 2012


Uranyl dinitrate trihydrate, UO 2 (NO 3 ) 2 (H 2 O) 3
journal, December 2002


Characterization of Uranium Oxides Using in Situ Micro-Raman Spectroscopy
journal, September 2000


The Infrared Spectra of some Uranyl Compounds
journal, June 1960


Density Functional Analysis of the Trigonal Uranyl Equatorial Coordination in Hexahomotrioxacalix[3]arene-based Macrocyclic Complexes
journal, February 2010


Infrared spectra of some uranyl nitrate complexes
journal, September 1967


Measurement and use of absolute infrared absorption intensities of neat liquids
journal, January 1995


Infrared spectroscopic studies of some uranyl nitrate complexes
journal, January 1979


Characterization of principal clinker minerals by FT-Raman microspectroscopy
journal, January 1994


Dehydration and thermal decomposition of uranyl nitrates in the presence of steam
journal, June 1965


Some observations on the isothermal dehydration of uranyl(VI) nitrate hexahydrate above room temperature
journal, January 1973


Accurate and simple analytic representation of the electron-gas correlation energy
journal, June 1992


The hydration number n of calcium dipicolinate trihydrate, CaDP·nH2O, and its effect on the IR spectra of sporulated Bacillus bacteria
journal, May 2010


A neutron diffraction study of uranyl nitrate hexahydrate
journal, October 1965


Neutron diffraction study of uranyl nitrate dihydrate
journal, February 1971


The uranium-oxygen system: U3O8-UO3
journal, March 1961


Thermal infrared (2.5–13.5 μm) spectroscopic remote sensing of igneous rock types on particulate planetary surfaces
journal, January 1989


Electronic Structure, Spectra, and Magnetic Properties of Oxycations. III. Ligation Effects on the Infrared Spectrum of the Uranyl Ion
journal, July 1961


Thermal dehydration of uranyl nitrate hydrates
journal, August 1968


Investigation of the polymorphs and hydrolysis of uranium trioxide
journal, August 2012


Thermal emission from particulate surfaces: A comparison of scattering models with measured spectra
journal, January 1995


Thermal and X-ray diffraction studies on the phase equilibria in the system UO2(NO3)2·6H2O–NaNO3
journal, June 2000


Salts of the 1,1,2,3,3,-pentacyanopropenide anion: crystallographic and spectroscopic studies
journal, December 1988


Midinfrared spectral features of rocks and their powders
journal, January 2002


Quantitative total and diffuse reflectance laboratory measurements for remote, standoff, and point sensing
conference, June 2014


The influence of particle size on infrared reflectance spectra
conference, June 2014


Infrared reflectance spectra: effects of particle size, provenance and preparation
conference, October 2014


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