Development of binder system for manufacturing metallic and ceramic parts by Powder Injection Molding technology

The technology is used by manufacturing companies of metallic and ceramic parts. The PIM companies have an important problem: they have to use a patented feedstock. This fact causes an increasing of the cost of final product. Moreover sometimes is difficult to obtain parts from several materials because only exists few commercial feedstocks. We offer some innovative aspects, the possibility of development of feedstocks from different ceramic and metallic powders and different morphologic and surface characteristics

Using Metal-Organic Framework HKUST-1 for the Preparation of High-Conductive Hybrid Membranes Based on Multiblock Copolymers for Fuel Cells

Novel proton-conducting hybrid membranes consisting of sulfonated multiblock copolymer of polysulfone and polyphenylsulfone (SPES) reinforced with a HKUST-1 metal-organic framework (MOF) (5, 10, and 20 wt. %) were prepared and characterized for fuel cell applications. The presence of the MOF in the copolymer was confirmed by means of FE-SEM and EDS. The hybrid membranes show a lower contact angle value than the pure SPES, in agreement with the water uptake (WU%), i.e., by adding 5 wt. % of the MOF, this parameter increases by 20% and 40% at 30 °C and 60 °C, respectively. Additionally, the presence of the MOF increases the ion exchange capacity (IEC) from 1.62 to 1.93 mequivH+ g−1. Thermogravimetric analysis reveals that the hybrid membranes demonstrate high thermal stability in the fuel cell operation temperature range ( 85 MPa in the Na+ form). Proton conductivity was analyzed using EIS, achieving the highest value with a 5 wt. % load of the HKUST-1. This value is lower than that observed for the HKUST-1/Nafion system. However, polarization and power density curves show a remarkably better performance of the hybrid membranes in comparison to both the pure SPES and the pure Nafion membranesThis work was funded by the Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER/UE), PID-2019-106662RB-C43, by the Spanish Government, MAT2016-78632-C4-3-R, by the Regional Government PEM4ENERGY-CM-UC3M funded by the call “Programa de apoyo a la realización de proyectos interdisciplinares de I + D para jóvenes investigadores de la Universidad Carlos III de Madrid 2019–2020” under the frame of the “Con-venio Plurianual Comunidad de Madrid-Universidad Carlos III de Madrid”, and by the Ministry of Science and Higher Education of the Russian Federation (State assignment in the field of scientific activity, № 0852-2020-0019). The authors would like to thank the following institutions for funding the projects: the Agencia Española de Investigación/Fondo Europeo de Desarrollo Regional (FEDER/UE): Projects PID2019-106662RBC43 and MAT2016-78362-C4-3-R, and the Comunidad de Madrid: Projects “Excelencia para el Profesorado Universitario”—(EPUC3M04) and PEM4ENERGY-CM-UC3

Sulfonated Polysulfone/TiO2(B) Nanowires Composite Membranes as Polymer Electrolytes in Fuel Cells

New proton conducting membranes based on sulfonated polysulfone (sPSU) reinforced with TiO2 (B) nanowires (1, 2, 5 and 10 wt.%) were synthesized and characterized. TiO2 (B) nanowires were synthesized by means of a hydrothermal method by mixing TiO2 precursor in aqueous solution of NaOH as solvent. The presence of the TiO2 (B) nanowires into the polymer were confirmed by means of Field Emission Scanning Electron Microscopy, Fourier transform infrared and X-ray diffraction. The thermal study showed an increase of almost 20 ◦C in the maximum temperature of sPSU backbone decomposition due to the presence of 10 wt.% TiO2 (B) nanowires. Water uptake also is improved with the presence of hydrophilic TiO2 (B) nanowires. Proton conductivity of sPSU with 10 wt.% TiO2 (B) nanowires was 21 mS cm−1 (at 85 ◦C and 100% RH). Under these experimental conditions the power density was 350 mW cm−2 similar to the value obtained for Nafion 117. Considering all these obtained results, the composite membrane doped with 10 wt.% TiO2 (B) nanowires is a promising candidate as proton exchange electrolyte in fuel cells (PEMFCs), especially those operating at high temperatures.The authors would like to thank the following Institution for funding the Projects: Agencia Española de Investigación /Fondo Europeo de Desarrollo Regional (FEDER/UE): Projects PID2019-106662RBC43 and MAT2016-78362-C4-3-R. Comunidad de Madrid: Projects "Excelencia para el Profesorado Universitario"—EPUC3M04) and PEM4ENERGY-CM-UC3M

Conductores iónicos de Litio basados en supercondutores de alta temperatura

Se han preparado nuevos materiales de formula "lixba2trcu3o7" (tr= y,pr) a partir de la reacción de n-buli con ba2trcu3o7. Estos materiales resultan ser intercrecimientos de diferentes fases de la familia ba4tr2cu6+no14+n, fundamentalmente los términos n=1 y n=2. En lo que a las propiedades físico-químicas se refiere, estos materiales presentan una conductividad iónica de litio comparable a la de otros buenos conductores iónicos tipo beta-alumina. Cuando tr=y los materiales presentan transición superconductora a la misma temperatura, aunque la fracción de muestra superconductora disminuye a medida que aumenta el contenido en litio. Por otro lado, cuando tr=pr el material no presenta transición superconductora ni antes ni después de la reacción con n-buli. Estudios de simulación han revelado que el litio estaría situado en las nuevas fases que aparecen como intercrecimientos dentro la fase original

Proton conductive Zr-Phosphonate UPG-1-Aminoacid insertion as proton carrier stabilizer

Proton exchange membrane fuel cells (PEMFCs) are an attractive green technology for energy generation. The poor stability and performances under working conditions of the current electrolytes are their major drawbacks. Metal-Organic Frameworks (MOFs) have recently emerged as an alternative to overcome these issues. Here, we propose a robust Zr-phosphonate MOF (UPG-1) bearing labile protons able to acta priorias an efficient electrolyte in PEMFCs. Further, in an attempt to further enhance the stability and conductivity of UPG-1, a proton carrier (the amino acid Lysine, Lys) was successfully encapsulated within its porosity. The behaviors of both solids as an electrolyte were investigated by a complete experimental (impedance spectroscopy, water sorption) and computational approach (MonteCarlo, water sorption). Compared with the pristine UPG-1, the newly prepared Lys@UPG-1 composite showed similar proton conductivity but a higher stability, which allows a better cyclability. This improved cyclability is mainly related to the different hydrophobic-hydrophilic balance of the Lys@UPG-1 and UPG-1 and the steric protection of the reactive sites of the MOF by the Lys.This research was funded by Raphuel project (ENE2016-79608-C2-1-R, MINECO-AEI/FEDER, UE), a 2017 Leonardo Grant for Researchers and Cultural Creators BBVA Foundation (PolyMOF) and the Ramón Areces Fundation project H+MOFs. PH acknowledges the Spanish Ramon y Cajal Programme (2014-16823). SMFV thanks to the Spanish Ministerio de Educación, Cultura y Deporte for “José Castillejo” mobility programme (Ref. CAS18/00470)Publicad

Synthesis and characterization of sulfonated PEEK-WC-PES copolymers for fuel cell proton exchange membrane application

In this work we have developed new sulfonated cardo (lactonic group) PEEK-WC-PES random copolymers with different molar ratio. The degree of sulfonation was determined from elemental analysis and ion-exchange capacity (IEC). Sulfonation levels from 0.64 to 1 were easily achieved by varying and controlling the reaction conditions. Proton conductivity was evaluated by impedance spectroscopy (EIS). Activation energy for proton transport, determined by conductivity measurements ranged between 11 and 15 kJ mol(-1), suggesting a vehicular proton transport mechanism. The membrane with better performance in single fuel cell was PEEK-SWC-PES 70:30 with maximum power and current densities of 93.6 mW cm(-2) and 340 mA cm(-2), respectively.This study was supported by Spanish Ministry of Economy and Competitiveness MINECO with projects MAT2016-78362-C4-3-R and MAT2013-46452-C4-3R and by the Regional Program through the Projects MATERYENER3CM S2013/MIT-2753 and PILCONAER S2013/MAE-2975 of the Community of Madrid. This research was supported by mobility grant of Universidad Carlos III de Madrid, Spain.Publicad

Study of the La₁/₂+₁/₂ₓLi₁/₂-₁/₂ₓTi₁-ₓAlₓO₃ (0 ≤ x ≤ 1) solid solution. A new example of percolative system in fast ion conductors

The synthesis by solid state reaction of new fast ion conductors with perovskite structure was carried out. The crystal structure and electric properties of the La1/2+1/2xLi1/2-1/2xTi1-xAlxO3 (0 ≤ x ≤ 1) solid solution were investigated by powder X-ray diffraction and impedance spectroscopy. All compositions of the La1/2Li1/2TiO3-LaAlO3 system, exhibited a single cubic perovskite structure (ac approximate to 3.87-3.79 angstrom; SG Pm-3m). The progressive decrease in the unit cell parameters agrees with the lower ionic radii of Al3+ in relation to Ti4+, which are allocated in the same octahedra. An upward deviation from the lineal ideal solid solution behavior described by Vegard's law was observed and it was tentatively associated with a volume excess created by solid dilution of non-isovalent cations. Structural features were deduced from Rietveld analysis of XRD patterns. Ti(Al)O6 octahedra are regular and La/vacancies are randomly distributed in A-site of the perovskite. The conductivity decreased almost four orders of magnitude with the Li content. This important decrease on the conductivity was attributed to the charge carrier (Li+) decrease and the blockade of the perovskite conduction pathways by La ions, according to a three dimensional percolative process. In consequence we present here a new example of percolative system of ionic conductors and the results confirm the important role played by effective vacant A-sites, neff = [Li] + nA, on Li conductivity of this fast ion conductors family with perovskite structure.Authors thank financial support received from MINECO (MAT2013-46452-C4-3-R and MAT2016-78362-C4-3-R projects), regional CAM government (MATERYENER 3CM, P2013/MIT-2753 program) and the European Commission (Program-IRSES FP7-PEOPLE Project ID: 247579 (NANOLICOM)

Engineering the electrical and optical properties of graphene oxide via simultaneous alkali metal doping and thermal annealing

In order to extend the application of graphene oxide (GO) in the area of electronic industries, enhancing the electrical properties of GO as a cost-effective alternative for graphene seems mandatory. Engineering the electrical properties of GO can be achieved in two different approaches: the oxygen functional group reduction and doping GO with chemical dopants. Here, both approaches were utilized to tune the electrical properties of GO toward its application as cathode; first, GO was doped with alkali metal dopants, and later, the doped samples were thermally reduced. Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy were utilized to study the chemical composition of the doped samples. The even distribution of the dopants on the GO surface presented via the EDX elemental map, with no sign of particle development. After doping GO with alkali metals followed by thermal reduction, the sheet resistance of the doped samples was decreased from 311.0 kU/sq to as low as 32.1 kU/sq. Moreover, the optical properties of GO were effectively engineered via the different doping agents. The ultra-violet photoelectron spectroscopy showed that the shift of the work function of GO was as high as 1.74 eV, after doping followed by thermal reduction. (C) 2020 The Author(s). Published by Elsevier B.V.11Nsciescopu

Interplay between humidity, temperature and electrical response of a conductivity sensor based on a La2LiNbO6 double perovskite

The La2LiNbO6 perovskite has been prepared in the polycrystalline form by a solid state reaction. Structural characterization by means of monochromatic X-ray and neutron powder diffraction (XRD and ND) and Rietveld refinement showed that the crystal structure belongs to the group of 1 : 1 B-site rock-salt ordered double perovskites with the most common tilting system amongst them being a-a-b+ (S. G. P21/n, a = 5.61612(3), b = 5.76645(2), c = 7.94107(4) degrees A, b = 90.276(2)degrees). Scanning Transmission Electron Microscopy (STEM) evidences that there is no cross-substitution between Li and Nb and that a remaining portion of lanthanum is randomly located in the projected positions of lithium. Impedance spectroscopy has been used to analyse the electrical-response properties of the materials. Conductivity is strongly dependent on the relative humidity (RH), changing by about 3 orders of magnitude between 25 and 90% RH. However, no conductivity increase with change in RH% is observed when the lateral surfaces of the sensor are covered with paraffin. This confirms that adsorption of water by the sample plays a crucial role in modulating the conduction mechanism. La2LiNbO6 also exhibits a very good durability, reproducibility, response time, hysteresis and dynamic linearity to be considered as a promising sensing material for a practical humidity sensor.This work has been supported by Projects funded by the regional government (Comunidad de Madrid through MATERYENER3CM S2013/MIT-2753) and the Spanish Government, (MICINN through MAT2016-78362-C4-3R and MAT2016-78362-C4-4R). V.D.N. thanks the University Carlos III of Madrid for the "8220;Cátedras de Excelencia UC3M-Santander"; (Chair of Excellence UC3M-Santander)