Nanomaterials (Dec 2020)

Uranium Carbide Fibers with Nano-Grains as Starting Materials for ISOL Targets

  • Sanjib Chowdhury,
  • Leonor Maria,
  • Adelaide Cruz,
  • Dario Manara,
  • Olivier Dieste-Blanco,
  • Thierry Stora,
  • António Pereira Gonçalves

DOI
https://doi.org/10.3390/nano10122458
Journal volume & issue
Vol. 10, no. 12
p. 2458

Abstract

Read online

This paper presents an experimental study about the preparation, by electrospinning, of uranium carbide fibers with nanometric grain size. Viscous solutions of cellulose acetate and uranyl salts (acetate, acetylacetonate, and formate) on acetic acid and 2,4-pentanedione, adjusted to three different polymer concentrations, 10, 12.5, and 15 weight %, were used for electrospinning. Good quality precursor fibers were obtained from solutions with a 15% cellulose acetate concentration, the best ones being produced from the uranyl acetate solution. As-spun precursor fibers were then decomposed by slow heating until 823 K under argon, resulting in a mixture of nano-grained UO2 and C fibers. A last carboreduction was then carried out under vacuum at 2073 K for 2 h. The final material displayed UC2−y as the major phase, with grain sizes in the 4 nm–10 nm range. UO2+x was still present in moderate concentrations (~30 vol.%). This is due to uncomplete carboreduction that can be explained by the fiber morphology, limiting the effective contact between C and UO2 grains.

Keywords