24 research outputs found

    Materiales Condensados y con Estructura Abierta basados en Fosfitos de Metales 3d

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    438 p.En la búsqueda de nuevos materiales con posibles aplicaciones tecnológicas, el oxoanión fosfito, (HPO3)2- es un candidato excelente para la obtención de nuevas estructuras. Su topología pseudotetraédrica (o piramidal) le confiere una gran versatilidad a la hora de formar parte de nuevas fases con estructuras tanto condensadas como abiertas

    Fluorinated mixed valence Fe(ii)-Fe(iii) phosphites with channels templated by linear tetramine chains. Structural and magnetic implications of partial replacement of Fe(ii) by Co(ii)

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    Three new fluorinated mixed valence Fe(ii)-Fe(iii) phosphites were synthesized by employing mild hydrothermal conditions. (H4baepn) 0.5[FeIII 2.3FeII 1.7(H2O)2(HPO3) 4-(x+y)(HPO4)x(PO4) yF4] (x ≃ 0.13, y ≃ 0.3) (1) (baepn = N,N′-bis(2-aminoethyl)-1,3-propanediamine (C7N 4H20)) and the Co(ii)-substituted phase with the formula (H4baepn)0.5[FeIII 2.0Fe II 0.71CoII 1.29(H2O) 2(HPO3)4-x(HPO4)xF 4] (x ≃ 0.38) (2) were studied by single crystal X-ray diffraction. The phase with the major content of Co(ii), (H4baepn) 0.5[FeIII 2.0FeII 0.62CoII 1.38(H2O) 2(HPO3)4-x(HPO4)xF 4] (x ≃ 0.38) (3) was obtained as a polycrystalline powder and studied by Rietveld refinement by using the structural model of 2. These compounds were characterized by ICP-Q-MS, thermogravimetric and thermodiffractometric analyses, and XPS, IR, UV/vis and Mössbauer spectroscopy. The single crystal data indicate that phases 1 and 2 crystallize in the P21/c space group with lattice parameters a = 13.6808(4), b = 12.6340(2), c = 12.7830(3) Å and β = 116.983(4)° for 1 and a = 13.6823(4), b = 12.6063(3), c = 12.7535(4) Å and β = 116.988(4)° for 2, with Z = 4. The reciprocal space of 1 shows satellite reflections with a modulation wavevector q = 0.284(2)a* which indicate an incommensurate long-range order. The average structure of these compounds is built up by a 3D lattice constructed by inorganic layers of Fe(iii) chains and Fe(ii) and Co(ii) dimers joined by phosphite groups partially substituted by HPO4 and PO4 tetrahedral groups. These anionic layers stack along the [100] direction encapsulating linear tetramines in eight-membered open channels involving host-guest interactions. Magnetic measurements of 1 and 3 showed antiferromagnetic coupling as the major interactions, exhibiting a weak ferromagnetic component together with a spin glass transition at low temperature in the case of 1. Heat capacity measurements showed a small anomaly at 20.5 K for 1 and a sharp magnetic peak at 28 K for 3. Unexpectedly, the small anomaly observed in 1 increased with the magnetic field and became better defined. © the Partner Organisations 2014

    Open and closed forms of the interpenetrated [Cu2(Tae)(Bpa)2](NO3)2•nH2O cationic coordination polymer: magnetic properties and high pressure CO2/CH4 gas sorption.

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    Two closed and one open structural forms of the interpenetrated [Cu2(Tae)(Bpa)2](NO3)2•nH2O (H2Tae= 1,1,2,2-tetraacetylethane, Bpa= 1,2-Bis(4-pyridyl)ethane) cationic coordination polymer have been synthesized. Three crystallographically related interpenetrated “ths” cationic nets encapsulate water molecules and nitrate anions giving rise to the closed structural forms of [Cu2(Tae)(Bpa)2](NO3)2•nH2O. Depending on the location of water molecules and nitrate groups, two different closed forms, with 5.5 and 3.6 crystallization water molecules have been obtained. Thermal activation of the closed structures gives rise to a 29% expansion of the unit cell. This closed to open transformation is reversible, and is triggered by the loss or uptake of solvent. The high pressure gas adsorption experiments show similar selectivity values towards CO2 for CO2/CH4 mixtures than that showed by some metal organic frameworks without unsaturated metal sites, and isosteric heats for CO2 adsorption similar to that for the HKUST-1 compound.Ministerio de Economía y Competitividad (MAT2016-76739-R (AEI/FEDER, EU). Gobierno Vasco (Basque University Research System Group, IT-630-13 and Economic Development and Competitiveness, ACTIMAT (KK-2015/00094) and LISOL (KK-2016/00095) projects, ELKARTEK program)

    Modulation of the Bifunctional CrVI to CrIII Photoreduction and Adsorption Capacity in ZrIV and TiIV Benchmark Metal-Organic Frameworks

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    The presence of hexavalent chromium water pollution is a growing global concern. Among the currently applied technologies to remove CrVI, its adsorption and photocatalytic reduction to CrIII less mobile and toxic forms are the most appealing because of their simplicity, reusability, and low energy consumption. However, little attention has been paid to bifunctional catalysts, that is, materials that can reduce CrVI to CrIII and retain both hexavalent and trivalent chromium species at the same time. In this work, the dual CrVI adsorption–reduction capacity of two iconic photoactive water-stable zirconium and titanium-based metal–organic frameworks (MOFs) has been investigated: UiO-66-NH2 and MIL-125. The bifunctionality of photoactive MOFs depends on different parameters, such as the particle size in MIL-125 or organic linker functionalization/defective positions in UiO-66 type sorbents. For instance, the presence of organic linker defects in UiO-66 has shown to be detrimental for the chromium photoreduction but beneficial for the retention of the CrIII phototransformed species. Both compounds are able to retain from 90 to 98% of the initial chromium present at acidic solutions as well as immobilize the reduced CrIII species, demonstrating the suitability of the materials for CrVI environmental remediation. In addition, it has been demonstrated that adsorption can be carried out also in a continuous flux mode through a diluted photoactive MOF/sand chromatographic column. The obtained results open the perspective to assess the bifunctional sorption and photoreduction ability of a plethora of MOF materials that have been applied for chromium capture and photoreduction purposes. In parallel, this work opens the perspective to develop specific chemical encoding strategies within MOFs to transfer this bifunctionality to other related water remediation applications.The authors thank the financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) through projects MAT2016-76739-R (AEI/FEDER, EU) and MAT2016-76039-C4-3-R (AEI/FEDER, UE) (including FEDER financial support) and from the Basque Government Industry and Education Departments under the ELKARTEK (LION, ACTIMAT), HAZITEK (SIMAN) and PIBA (PIBA-2018-06) programs, respectively. The European Commission Research & Innovation H2020-MSCA-RISE-2017 (Ref.: 778412) INDESMOF project

    Características epidemiológicas de las nuevas infecciones causadas por el VIH comparadas con los casos de sida. La epidemia de VIH/sida en el País Vasco

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    ResumenObjetivoDescribir las características epidemiológicas de los nuevos diagnósticos de infección por el VIH en el período 1997- 2001 y comparlas con los casos de sida (1991-2001).MétodosSe han recogido retrospectivamente los datos de las nuevas infecciones por el VIH ocurridas en el País Vasco (1997-2001) y se han comparado con los casos de sida (1991- 2001).ResultadosSe han diagnosticado 912 nuevas infecciones por el VIH. El diagnóstico de VIH coincidió con el de sida en 299 (32,8%) de las nuevas infecciones. Las relaciones heterosexuales han sido el mecanismo de transmisión más frecuente, seguido de la transmisión por vía parenteral y las relaciones homosexuales y bisexuales, con diferencias significativas (p < 0,001) respecto a los casos de sida.ConclusionesLa transmisión sexual ha reemplazado al consumo de drogas por vía parenteral como mecanismo más frecuente de transmisión del VIH. Hay un alto porcentaje de pacientes con diagnóstico simultáneo de VIH y sida. Estos datos indican la necesidad de realizar nuevas estrategias de prevención.SummaryObjectiveTo describe the epidemiological characteristics of new cases of HIV infection diagnosed from 1997-2001 and compare them with AIDS cases (1991-2001).MethodsData were retrospectively collected on new cases of HIV infection detected in the Basque Country (1997-2001) and were compared with AIDS cases (1991-2001).ResultsA total of 912 new cases of HIV infection were diagnosed. In 299 of the new cases (32.8%), HIV and AIDS were diagnosed simultaneously. The most common mechanism of transmission was heterosexual transmission, followed by intravenous and homo/bisexual transmission. Significant epidemiological differences (p < 0.001) were found with regard to AIDS cases.ConclusionsSexual transmission has replaced intravenous drug use as the most common mechanism of HIV transmission. A large percentage of patients were simultaneously diagnosed with HIV and AIDS, indicating the need for new prevention strategies

    2024 roadmap for sustainable batteries

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    Modern batteries are highly complex devices. The cells contain many components-which in turn all have many variations, both in terms of chemistry and physical properties. A few examples: the active materials making the electrodes are coated on current collectors using solvents, binders and additives; the multicomponent electrolyte, contains salts, solvents, and additives; the electrolyte can also be a solid ceramic, polymer or a glass material; batteries also contain a separator, which can be made of glass fibres, polymeric, ceramic, composite, etc. Moving up in scale all these components are assembled in cells of different formats and geometries, coin cells and Swagelok cells for funamental testing and understanding, and pouch, prismatic and cylindrical cells for application. Given this complexity dictated by so many components and variations, there is no wonder that addressing the crucial issue of true sustainability is an extremely challenging task. How can we make sure that each component is sustainable? How can the performance can be delivered using more sustainable battery components? What actions do we need to take to address battery sustainability properly? How do we actually qualify and quantify the sustainability in the best way possible? And perhaps most importantly; how can we all work-academia and battery industry together-to enable the latter to manufacture more sustainable batteries for a truly cleaner future? This Roadmap assembles views from experts from academia, industry, research institutes, and other organisations on how we could and should achieve a more sustainable battery future. The palette has many colours: it discusses the very definition of a sustainable battery, the need for diversification beyond lithium-ion batteries (LIBs), the importance of sustainability assessments, the threat of scarcity of raw materials and the possible impact on future manufacturing of LIBs, the possibility of more sustainable cells by electrode and electrolyte chemistries as well as manufacturing, the important role of new battery chemistries, the crucial role of AI and automation in the discovery of the truly sustainable batteries of the future and the importance of developimg a circular battery economy

    2024 roadmap for sustainable batteries

    Get PDF
    Modern batteries are highly complex devices. The cells contain many components—which in turn all have many variations, both in terms of chemistry and physical properties. A few examples: the active materials making the electrodes are coated on current collectors using solvents, binders and additives; the multicomponent electrolyte, contains salts, solvents, and additives; the electrolyte can also be a solid ceramic, polymer or a glass material; batteries also contain a separator, which can be made of glass fibres, polymeric, ceramic, composite, etc. Moving up in scale all these components are assembled in cells of different formats and geometries, coin cells and Swagelok cells for funamental testing and understanding, and pouch, prismatic and cylindrical cells for application. Given this complexity dictated by so many components and variations, there is no wonder that addressing the crucial issue of true sustainability is an extremely challenging task. How can we make sure that each component is sustainable? How can the performance can be delivered using more sustainable battery components? What actions do we need to take to address battery sustainability properly? How do we actually qualify and quantify the sustainability in the best way possible? And perhaps most importantly; how can we all work—academia and battery industry together—to enable the latter to manufacture more sustainable batteries for a truly cleaner future? This Roadmap assembles views from experts from academia, industry, research institutes, and other organisations on how we could and should achieve a more sustainable battery future. The palette has many colours: it discusses the very definition of a sustainable battery, the need for diversification beyond lithium-ion batteries (LIBs), the importance of sustainability assessments, the threat of scarcity of raw materials and the possible impact on future manufacturing of LIBs, the possibility of more sustainable cells by electrode and electrolyte chemistries as well as manufacturing, the important role of new battery chemistries, the crucial role of AI and automation in the discovery of the truly sustainable batteries of the future and the importance of developimg a circular battery economy

    Materiales Condensados y con Estructura Abierta basados en Fosfitos de Metales 3d

    Get PDF
    438 p.En la búsqueda de nuevos materiales con posibles aplicaciones tecnológicas, el oxoanión fosfito, (HPO3)2- es un candidato excelente para la obtención de nuevas estructuras. Su topología pseudotetraédrica (o piramidal) le confiere una gran versatilidad a la hora de formar parte de nuevas fases con estructuras tanto condensadas como abiertas

    Enhancement of the luminescent properties of a new red-emitting phosphor, Mn2(HPO3)F2, by Zn substitution

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    The Mn2(HPO3)F2 phase has been synthesized as single crystals by using mild hydrothermal conditions. The compound crystallizes in the orthorhombic Pnma space group, with unit cell parameters of a = 7.5607(8), b = 10.2342(7), and c = 5.5156(4) Å, with Z = 4. The crystal structure consists of a three-dimensional framework formed by alternating (010) layers of [MnO3F3] octahedra linked up by three connected [HPO3] tetrahedra. Luminescence measurements were performed at different temperatures between 10 and 150 K. The 10 k emission spectrum of the octahedrally coordinated Mn(II) cation exhibits a broad band centered at around 615 nm corresponding to the 4T1 → 6A1 transition. In order to explore the effect of the Mn(II) concentration and the possibility of enhancing the luminescence properties of the Mn(II) cation in Mn2(HPO3)F 2, different intermediate composition members of the finite solid solution with the general formula (MnxZn1-x) 2(HPO3)F2 were prepared and their luminescent properties studied. The magnetic and specific heat behavior of M2(HPO 3)F2 (M = Mn, Fe) have also been investigated. The compounds exhibit a global antiferromagnetic ordering with a spin canting phenomenon detected at approximately 30 K. The specific heat measurements show sharp λ-type peaks at 29.7 and 33.5 k for manganese and iron compounds, respectively. The total magnetic entropy is consistent with spin S = 5/2 and S = 2 of Mn(II) and Fe(II) cations. © 2011 American Chemical Society.Peer Reviewe

    Low temperature red luminescence of a fluorinated Mn-doped zinc selenite

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    M2(SeO3)F2 (M = Zn (1), Mn (2)) stoichiometric phases together with the Zn2-xMnx(SeO 3)F2 compound doped at various concentrations (x = 0.002-0.2) were synthesized by employing mild hydrothermal conditions. These compounds have been characterized by scanning electron microscopy (SEM), Rietveld refinement of the X-ray powder diffraction patterns, ICP-Q-MS, thermogravimetric and thermodiffractometric analyses, and IR, UV/vis and electron paramagnetic resonance (EPR) spectroscopies. Compounds 1 and 2 crystallize in the orthorhombic Pnma space group with lattice parameters: a = 7.27903(4), b = 10.05232(6) and c = 5.26954(3) Å for the zinc species and a = 7.50848(9), b = 10.3501(12) and c = 5.47697(6) Å for the manganese phase, with Z = 4. The crystal structures of these compounds are isotypic and are built up from a 3D framework constructed by (010) sheets of [MO 3F3] octahedra linked up by [SeO3] building units. Luminescence measurements of Mn2(SeO3)F2 were performed at different temperatures between 10 and 150 K. At 10 K, the emission spectrum consists of a broad band peaked at around 660 nm related to the 4T1g → 6A1g transition in octahedrically coordinated Mn2+. Moreover, the influence of temperatures up to 295 K and the Mn concentration on the luminescent properties of the Zn2-xMnx(SeO3)F2 system were systematically studied. Magnetic measurements of 2 show antiferromagnetic coupling as the major interactions exhibiting a spin canting at low temperature. © 2013 The Royal Society of Chemistry.This work has been financially supported by the “Ministerio de Ciencia e Innovación” (MAT2010-15375 and FIS2011-27968) and the "Gobierno Vasco" (IT630-13) and the “UPV/EHU” (UFI11/15), which we gratefully acknowledge. Financed by the National Program for the Promotion of Human Resources within the National Plan of Scientific Research, Development and Innovation, “Ministerio de Ciencia y Educación” and “Fondo Social Europeo” (FSE).Peer Reviewe
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