Laura J Bonales

Laura J Bonales
Complutense University of Madrid | UCM · Department of Physical Chemistry I

About

43
Publications
6,842
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
705
Citations

Publications

Publications (43)
Article
UO2 corrosion is a key issue in the study of the safe storage of spent nuclear fuel (SNF). In this work, corrosion experiments were performed on UO2 samples exposed to ¹⁸O labelled water during 290 days at room conditions, thereafter a complete analysis of the solid and leachant (labelled water) allow us obtaining new data and exploring new methods...
Article
In this work, we studied the dehydration process of the glycine-MgSO4·5H2O complex under Mars-relevant conditions (99% CO2 and 0.6% H2O under ultra violet (UV) irradiation exposure at 7-mbar pressure and high vacuum conditions: 8 ·10-5 and 5 ·10-5 mbar) by in situ Raman spectroscopy inside a planetary atmosphere and surface chamber (PASC). This wor...
Article
In a deep geological repository (DGR) scenario, uranium oxidized in aqueous systems will be stabilized as UO22+ (hexavalent uranium), as a consequence of tetravalent uranium oxidation by radiolytic byproducts. Uranyl cationic species (UO22+) in different speciation forms are expected to be found at the whole pH range conditions. The importance of U...
Article
The ligand acetohydroxamic acid (AHA) suffers hydrolysis at acidic conditions. This reaction has been studied for a long time, due to its implications in different applications, by using indirect colorimetric methods. This work shows how Raman spectroscopy can be very useful as a direct technique for measuring the hydrolysis kinetics of AHA, faster...
Article
Acetohydroxamic acid (AHA) has been widely used in the development of reprocessing processes for spent nuclear fuel (SNF) due to its ability to form hydrophilic complexes preferentially with tetravalent metals and to help the control of their oxidation states. It is also well known that AHA undergoes hydrolytic degradation at the acidic conditions...
Article
The high surface area of graphene oxide (GO) and the different polar and oxygenated groups on its surface ensure its high sorption capacity for different metals from aqueous solutions. Moreover, its elevated stability under some harsh conditions could also allow the application of GO in real nuclear waste management. In this paper, the 241Am(III) a...
Preprint
Full-text available
The crystal structure, hydrogen bonding, mechanical properties and Raman spectrum of the lead uranyl silicate monohydrate mineral kasolite, Pb(UO2)(SiO4)H2O, are investigated by means of first-principles solid-state methods based on density functional theory using plane waves and pseudopotentials. The computed unit cell parameters, bond lengths and...
Article
Full-text available
The crystal structure, hydrogen bonding, mechanical properties and Raman spectrum of the lead uranyl silicate monohydrate mineral kasolite, Pb(UO2 )(SiO4 )· H2O, are investigated by means of first-principles solid-state methods based on density functional theory using plane waves and pseudopotentials. The computed unit cell parameters, bond lengths...
Conference Paper
El uso de métodos teóricos de estado sólido en el estudio de las estructuras cristalinas, espectros vibracionales y propiedades mecánicas y termodinámicas de materiales que contienen uranio ha mostrado la gran utilidad de esta metodología tanto como complemento de la metodología experimental para interpretar y completar los resultados obtenidos por...
Article
The layered uranyl silicate clay-like mineral, uranophane-α, Ca(UO 2 ) 2 (SiO 3 OH) 2 ·5H 2 O, was studied by first-principles calculations based on the density functional theory method. The structure, observed in nature in a wide variety of compounds having the uranophane sheet anion topology, is confirmed here for the first time by means of rigor...
Article
A pre- and post-oxidation detailed Raman analysis has been carried out on a variety of (U1-y,Cey)O2-x oxides (y = 0.01, 0.03, 0.10, 0.15, 0.40). The changes undergone in the Raman spectrum of UO2 as a function of Ce incorporation have been examined, thus extracting valuable information on the structural features and changes of these solid solutions...
Article
The position of the main spectral features (located at ∼445, ∼575, ∼625, ∼925 and ∼1145 cm⁻¹) in the Raman spectrum of UO2 has been examined from room temperature up to 600 °C. The wavenumber shifts measured for the observed bands have allowed us to obtain the temperature dependence (dω/dT) of the different vibrational modes. Our measurements corro...
Article
A reliable method to probe and characterise the oxidation of actinide oxides by means of Raman spectroscopy is introduced. The present so-called Raman laser heating method enables studying the behaviour of various compounds at high temperatures and under a given atmosphere with the unique alteration of a small amount of sample, which is certainly a...
Article
When the wavelength of the Raman scattered light coincides with the absorption spectrum of the sample, a phenomenon known as Raman self-absorption occurs. If the absorption wavelength range matches completely with the Raman wavenumber range for a given excitation line (high absorption), this process causes spectra with poor signal-to-noise-ratio, m...
Article
Uranyl silicate mineral soddyite, (UO2)2(SiO4)·2(H2O), is a fundamental component of the paragenetic sequence of secondary phases that arises from the weathering of uraninite ore deposits and corrosion of spent nuclear fuel. In this work, soddyite was studied by first principle calculations based on the density functional theory. As far as we know,...
Article
This work presents a systematic Raman study of the matrix oxidation in a variety of (U1-y, Puy)O2 compositions (0 ≤ y ≤ 0.46) at different temperatures, between 250 °C and 400 °C. Our results indicate that the increase in Pu content hinders the oxidation process of the dioxide matrix. Further oxidation of the uranium-plutonium mixed dioxides in air...
Article
Gamma uranium trioxide, γ-UO3, is one of the most important polymorphs in uranium trioxide system which is common throughout the nuclear fuel cycle and used industrially in the reprocessing of nuclear fuel and uranium enrichment. In this work, a detailed theoretical solid-state density functional theory study of this material was carried out. The c...
Article
Although the thermal conductivity of liquid water is well established, many conflicting values for the thermal conductivity of ice have been reported in the literature. This work demonstrates that the significant differences in the reported ice thermal conductivities can be attributed to differences in the freezing conditions and measurement proced...
Article
Full-text available
The Raman spectrum of plutonium dioxide is studied both experimentally and theoretically. Particular attention has been devoted to the identification of high-energy modes at 2110 cm-1 and 2620 cm-1, whose attribution has so far been controversial. The temperature dependence of both modes suggests an electronic origin for them. Original Crystal Fiel...
Article
Thermodynamic and mechanical properties of rutherfordine, a uranyl carbonate mineral, were studied by means of first principle calculations based on density functional theory. Thermodynamic properties, including enthalpy, free energy, entropy, heat capacity and Debye temperature were evaluated as a function of temperature and compared with experime...
Article
Raman spectroscopy studies have been performed on the one hand to identify different materials related to spent nuclear fuel (SNF), and on the other hand to study the behavior of SNF at different storage conditions. Specifically, the expected oxidation of the SNF matrix under dry storage conditions and the formation of secondary phases (SP), as a r...
Article
A good understanding of the spent fuel matrix (UO 2 ) behavior under predisposal activities conditions is required for the proper performance assessment of a final repository. Hence, the oxidation evolution of UO 2 under dry interim storage conditions, as a main predisposal action within the Spanish strategy, needs to be addressed. For this aim, in...
Article
The design of a safe spent nuclear fuel repository requires the knowledge of the stability of the secondary phases which precipitate when water reaches the fuel surface. Studtite is recognized as one of the secondary phases that play a key-role in the mobilization of the radionuclides contained in the spent fuel. Thereby, it has been identified as...
Article
Raman spectra of 1,2-ethylenediamine (EDA) in aqueous solutions are used to demonstrate that EDA molecules experience an anti-gauche conformational change resulting from the interactions with water. The observed Raman shift reveals a compressive (hydrophobic) effect of water on both methylene and amino groups of EDA. Raman spectra of EDA at high pr...
Chapter
Full-text available
The use of the Raman technique is nowadays being widely spread in many scientific and industrial disciplines. The rise of this spectroscopy is due to the technology developed in some of its main components (the laser, charge-coupled device (CCD) sensors, gratings, filters, etc.), what reduces the cost of the equipment. Characterization by Raman spe...
Article
This work presents a detailed study of hyperstoichiometric UO2+x (0 < x < 0.25) oxides and an assessment of the structural evolution taking place as oxidation proceeds. For this purpose, different UO2+x powder samples with controlled degree of non-stoichiometry have been identified by thermogravimetric analysis and characterized by X-ray diffractio...
Conference Paper
Resumen/Summary Las fases secundarias rutherfordina y studtita se estudian en este trabajo por medio de espectroscopia Raman y cálculos computacionales basados en la teoría del funcional de la densidad (DFT). Para ello se ha desarrollado un pseudopotencial para el átomo de uranio que se valida generando la estructura de la ruterfordina con este pot...
Article
A rutherfordine mineral was studied by means of Raman spectroscopy combined with first principle calculations based on the density functional theory (DFT) method. The pseudopotential of a uranium atom was generated and its performance was evaluated for a series of uranium-containing minerals. The structure of rutherfordine was determined for two sy...
Article
Full-text available
The Raman spectrum of plutonium dioxide is studied both experimentally and theoretically. Particular attention has been devoted to the identification of high-energy modes at $2120$ cm$^{-1}$ and $2625$ cm$^{-1}$, the attribution of which has so far been controversial. The temperature dependence of both modes suggests an electronic origin. Crystal F...
Article
Uraninite is a mineral considered as an analogue of the spent fuel, and the study of its alteration products has been used to predict the secondary phases produced during the fuel storage under specific environmental conditions. In this work, we study by Raman spectroscopy the alteration by weathering of the primary uraninite from the uranium depos...
Conference Paper
Full-text available
El combustible nuclear que se utiliza actualmente en España consiste en pastillas de óxidos de uranio enriquecido (entre un 4 y un 5% de 235 U) encapsuladas en una vaina de Zircaloy, presurizadas en su interior con un gas inerte (helio). Un factor que contribuye decisivamente a la escasez de estudios experimentales relacionados con los combustibles...
Conference Paper
Full-text available
España lleva a cabo el ciclo abierto para la gestión del combustible irradiado de sus centrales nucleares. La solución adoptada dada la urgente necesidad de una mayor capacidad de almacenamiento, ha sido la construcción de un Almacén Temporal Centralizado (ATC), con una vida prevista de 100 años, donde se almacenarán a partir de 2017 tanto el combu...
Article
In this work, we study how structures develop on 2D dense binary colloidal monolayers as a function of the relative concentration of small/large particles. Translational and orientational distribution functions have been used to monitor the continuous phase transition through a detailed characterization of the global and local order. We have observ...
Article
Full-text available
We have studied the surface shear viscoelasticity of poly(tert-butyl-acrylate) Langmuir monolayers spread at the air/water interface, by tracking the Brownian motion of tracer particles with different sizes and surface chemical nature, trapped at the same interface. Surface shear moduli have been extracted from the particles mean square displacemen...
Article
Full-text available
The structure and the interaction potential of monolayers of charged polystyrene microparticles at fluid interfaces have been studied by optical microscopy. Microparticles of different sizes have been studied over a broad range of surface particle densities. The structural characterization is based on the analysis of images obtained by digital opti...
Article
Full-text available
We address a systematic study of the three-phase contact angle, θ, of microparticles at flat fluid-liquid interfaces by using different experimental methods. We measured the dependence of θ not only on the particle chemical composition and size, but also on the solvent used to spread the microparticles onto the fluid interface. We found a non-expec...
Article
Full-text available
Particle tracking has been shown to be a powerful technique for measuring bulk and interfacial rheology of flu-ids. The Brownian motion of microparticles trapped at interfaces is very sensitive to the viscosity of the subphase, and to the contact angle of the particles. The Stokes-Einstein relation is fulfilled if the friction factor is properly ta...
Article
The linear regime (LR) of viscoelastic behavior has been found to be limited to rather small values of strain, well below the strains found in many technological processes. A Fourier-transform method is described for analyzing the surface rheology data obtained in insoluble Langmuir polymer monolayers beyond the LR. In the concentrate regime, the m...
Article
The dynamics of the liquid-air interface of aqueous solutions of a tensioactive triblock copolymer (Pluronic F-68) has been studied using surface quasielastic light scattering over a broad range of concentrations and temperatures. Ancillary surface tension and bulk rheometry data have been obtained for the same system. The results show that the cla...

Network

Cited By

Projects

Projects (4)
Project
The project Spent Fuel Characterization and Evolution Until Disposal (SFC) is WP8 within the framework of the EURAD programme, aiming to provide a better understanding of spent nuclear fuel (SNF) properties from the perspective of pre-disposal activities, but also exploring aspects having an impact on long-term safety. The EURAD/SFC consortium brings together more than 20 partners with a range of skills and competences in spent fuel assessment, from management to experimental work. The consortium consists of national waste management organisations, research institutes, universities, technical support organisations and commercial organisations.
Project
- Characterization of the fundamental secondary phases of spent nuclear fuel using the theoretical solid state methodology. - Determination of the crystal structures and X-ray diffraction patterns of these phases and comparison with their experimental counterparts. - Determination of the Raman spectra, of these phases, comparison with the experimental spectra and band assignment . - Prediction of the mechanical and thermodynamic properties of these phases. Study of their mechanical and thermodynamic stability.
Archived project