Uranyl oxy-hydroxy-hydrate minerals are common alteration products of uraninite (UO2+x) which is chemically and structurally analogous to uranium dioxide nuclear fuel. Therefore, structural and spectroscopic investigations of these alteration minerals and their analogous anthropogenic counterparts can provide insight into the environmental behavior of nuclear fuel cycle ma…
Studtite is a common nuclear fuel cycle material that has been the focus of considerable research due to its role as a uranium ore concentrate. In a laboratory setting, studtite is commonly synthesized via the addition of liquid-phase hydrogen peroxide to an aqueous uranyl nitrate solution. The product produced from this process is a very fine, pale-yellow powder with crys…
Neptunium oxalate (Np(C2O4)2·6H2O) is a historically relevant solid phase used in nuclear processing as a precursor for neptunium dioxide (NpO2). Although Np oxalate has been synthesized and used for NpO2 production for decades, the thermal decomposition mechanism of this phase remains poorly understood and has not been evaluated in over 30 years. Conflicting reports in hi…
Diglycidyl ether of bisphenol F (DGEBF) is a common industrial epoxy resin, desired for its possible replacement of the bisphenol A (BPA) analogue DGEBA due to potential health hazards of BPA. During curing, crystallization of the DGEBF resin can cause inaccurate resin-to-hardener ratios, resulting in incomplete crosslinking; therefore, understanding the crystallization of…
Ianthinite ([U24+(UO2)4O6(OH)4(H2O)4]·5H2O) is an exotic mineral that possesses U in both tetravalent and hexavalent oxidation states and is structurally related to the U3O8 polymorphs, which are commonly encountered technogenic materials in the nuclear fuel cycle. Despite the similarities between U3O8 and ianthinite, and the importance of ianthinite in U paragenesis, no R…
The availability of actinide standard materials for use in nuclear safeguard applications is critical, as is thorough characterization thereof. Although accurate trace element compositions and isotopic considerations are paramount for deployment of reference standards, structural characterization is also essential towards accurately describing the chemical form and potenti…
Although oxidation mechanisms have been exhaustively studied for graphite, similar analyses of carbon fibers are comparatively sparse. Most prior work has focused on quantifying weight loss or assessing protective surface coatings designed to slow oxidation. The use of optical spectroscopic techniques for oxidation analyses is comparatively unexplored, but such techniques…
Single crystals of LnFe(SO4)3(H2O)2 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm; compounds 1–11) and LnFe(SO4)3(H2O) (Ln = Tm, Yb, Lu; compounds 12–14) were synthesized under hydrothermal conditions. Single-crystal X-ray diffraction (SCXRD) analysis revealed that the dihydrated compounds (1–11) crystallize in centrosymmetric (CS) structures, with the lanthanide ions a…
Recognized as the most stable phase of uranium oxide, α-U3O8 is widely used throughout the nuclear fuel cycle for safe storage and transportation. There is, however, a lack of understanding of the thermodynamic relationship between α-U3O8 and its polymorph, β-U3O8. This research contributes new knowledge regarding the kinetics and mechanism of a previously described mechan…
Polymer network structures in epoxy thermosets play an important role in the final thermoset material properties. However, analytical characterization of these network structures is difficult due to their amorphous nature. In this work, the application of evolved gas analysis–mass spectrometry (EGA-MS) to characterize the polymer network structures of bisphenol A (BPA)-bas…