Use of boiled hexamethylenetetramine and urea to increase the porosity of cerium dioxide microspheres formed in the internal gelation process

Hunt, R. D.; Collins, J. L.; Cowell, B. S.

doi:10.1016/j.jnucmat.2017.04.061

Title: Use of boiled hexamethylenetetramine and urea to increase the porosity of cerium dioxide microspheres formed in the internal gelation process

Abstract

Cerium dioxide (CeO₂) is a commonly used simulant for plutonium dioxide and for plutonium (Pu) in a mixed uranium (U) and Pu oxide [(U, Pu)O₂] in nuclear fuel development. This effort developed CeO₂ microspheres with different porosities and diameters for use in a crush-strength study. The internal gelation technique has produced CeO₂ microspheres with limited initial porosity. When an equal molar solution of urea and hexamethylenetetramine (HMTA) is gently boiling for 1 hr and used in the gelation process, the crystallite size and porosity of mixed U and thorium oxide microspheres and the (U, Pu)O₂ microspheres increased significantly. In this study with cerium, the combination of ammonium cerium nitrate and 1-h boiled HMTA-urea failed to produce a stable feed broth. However, when the 1-h heated HMTA-urea was combined with unheated HMTA-urea in 1 to 3 volume ratio or the boiling time of the HMTA-urea was reduced to 15-20 min, a stable solution of HMTA, urea, and Ce was formed at 273 K. This new Ce solution produced CeO₂ microspheres with much higher initial porosities. Intermediate porosities were possible when the heated HMTA/urea was aged prior to use.

Authors:

Hunt, R. D. ^[1]; Collins, J. L. ^[1]; Cowell, B. S. ^[1]

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:: Sat May 13 00:00:00 EDT 2017

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1408648

Alternate Identifier(s):: OSTI ID: 1396929

Grant/Contract Number:: AC05-00OR22725

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Nuclear Materials

Additional Journal Information:: Journal Volume: 492; Journal Issue: C; Journal ID: ISSN 0022-3115

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; Cerium oxide spheres; Internal gelation

Citation Formats


                    Hunt, R. D., Collins, J. L., and Cowell, B. S. Use of boiled hexamethylenetetramine and urea to increase the porosity of cerium dioxide microspheres formed in the internal gelation process.  United States: N. p., 2017. 
Web.  doi:10.1016/j.jnucmat.2017.04.061.

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                    Hunt, R. D., Collins, J. L., & Cowell, B. S. Use of boiled hexamethylenetetramine and urea to increase the porosity of cerium dioxide microspheres formed in the internal gelation process.  United States.  https://doi.org/10.1016/j.jnucmat.2017.04.061

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                    Hunt, R. D., Collins, J. L., and Cowell, B. S. Sat .  
"Use of boiled hexamethylenetetramine and urea to increase the porosity of cerium dioxide microspheres formed in the internal gelation process".  United States.  https://doi.org/10.1016/j.jnucmat.2017.04.061.  https://www.osti.gov/servlets/purl/1408648.

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@article{osti_1408648,

  title        = {Use of boiled hexamethylenetetramine and urea to increase the porosity of cerium dioxide microspheres formed in the internal gelation process},

  author       = {Hunt, R. D. and Collins, J. L. and Cowell, B. S.},

  abstractNote = {Cerium dioxide (CeO2) is a commonly used simulant for plutonium dioxide and for plutonium (Pu) in a mixed uranium (U) and Pu oxide [(U, Pu)O2] in nuclear fuel development. This effort developed CeO2 microspheres with different porosities and diameters for use in a crush-strength study. The internal gelation technique has produced CeO2 microspheres with limited initial porosity. When an equal molar solution of urea and hexamethylenetetramine (HMTA) is gently boiling for 1 hr and used in the gelation process, the crystallite size and porosity of mixed U and thorium oxide microspheres and the (U, Pu)O2 microspheres increased significantly. In this study with cerium, the combination of ammonium cerium nitrate and 1-h boiled HMTA-urea failed to produce a stable feed broth. However, when the 1-h heated HMTA-urea was combined with unheated HMTA-urea in 1 to 3 volume ratio or the boiling time of the HMTA-urea was reduced to 15-20 min, a stable solution of HMTA, urea, and Ce was formed at 273 K. This new Ce solution produced CeO2 microspheres with much higher initial porosities. Intermediate porosities were possible when the heated HMTA/urea was aged prior to use.},

  doi          = {10.1016/j.jnucmat.2017.04.061},

  journal      = {Journal of Nuclear Materials},

  number       = C,

  volume       = 492,

  place        = {United States},

  year         = {Sat May 13 00:00:00 EDT 2017},

  month        = {Sat May 13 00:00:00 EDT 2017}

}

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Works referenced in this record:

Fabrication of size-controlled CeO ₂ microparticles by a microfluidic sol–gel process as an analog preparation of ceramic nuclear fuel particles
journal, August 2013

Ye, Bin; Miao, Ji-Lang; Li, Jiao-Long
Journal of Nuclear Science and Technology, Vol. 50, Issue 8
DOI: 10.1080/00223131.2013.796897

Fabrication of dense (Th,U)O2 pellets through microspheres impregnation technique
journal, November 2008

Pai, Rajesh V.; Dehadraya, J. V.; Bhattacharya, Shovit
Journal of Nuclear Materials, Vol. 381, Issue 3
DOI: 10.1016/j.jnucmat.2008.07.044

Studies on preparation of (U0.47,Pu0.53)O2 microspheres by internal gelation process
journal, March 2013

Kumar, Ashok; Radhakrishna, J.; Kumar, N.
Journal of Nuclear Materials, Vol. 434, Issue 1-3
DOI: 10.1016/j.jnucmat.2012.11.009

The Basic Chemistry Involved in the Internal-Gelation Method of Precipitating Uranium as Determined by pH Measurements
journal, January 1987

Collins, J. L.; Lloyd, M. H.; Fellows, R. L.
Radiochimica Acta, Vol. 42, Issue 3
DOI: 10.1524/ract.1987.42.3.121

Uranium kernel formation via internal gelation
journal, January 2004

Hunt, Rodney D.; Collins, Jack L.
Radiochimica Acta, Vol. 92, Issue 12
DOI: 10.1524/ract.92.12.909.55110

Treatment techniques to prevent cracking of amorphous microspheres made by the internal gelation process
journal, October 2010

Hunt, R. D.; Montgomery, F. C.; Collins, J. L.
Journal of Nuclear Materials, Vol. 405, Issue 2
DOI: 10.1016/j.jnucmat.2010.08.007

Works referencing / citing this record:

Preparation of cerium dioxide microspheres by internal gelation with cerium citrate as precursor
journal, March 2019

Ding, Xueqiang; Ma, Jingtao; Zhou, Xiangwen
Journal of Sol-Gel Science and Technology, Vol. 90, Issue 2
DOI: 10.1007/s10971-019-04965-w

Fabrication of CeO2–Nd2O3 microspheres by internal gelation process using M(OH)m and [MCit∙xH2O] (M=Ce3+, Ce4+, and Nd3+) as precursors
journal, July 2019

Ding, Xueqiang; Ma, Jingtao; Zhou, Xiangwen
Journal of Sol-Gel Science and Technology, Vol. 92, Issue 1
DOI: 10.1007/s10971-019-05058-4

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Title: Use of boiled hexamethylenetetramine and urea to increase the porosity of cerium dioxide microspheres formed in the internal gelation process

Abstract

Citation Formats

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