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Artículos SCI



2024


Reactividad de Sólidos

Magnesium calcites for CO2 capture and thermochemical energy storage using the calcium-looping process

Perejón, A; Arcenegui-Troya, J; Sánchez-Jiménez, PE; Diánez, MJ; Pérez-Maqueda, LA
Environmental Research, 246 (2024) 118119

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In this study, a precipitation-based synthesis method has been employed to prepare magnesium calcites with the general formula Ca1-xMgxCO3, with the objective of use them in the calcium looping (CaL) process for CO2 capture (CaL-CCS) and thermochemical energy storage (CaL-CSP). The structure and microstructure of the samples have been characterized. It has been found by X-ray diffraction that the samples with a Ca:Mg molar ratio of 0.5:0.5 and 0.55:0.45 are phase pure, while the samples with molar ratios of 0.7:0.3 and 0.8:0.2 are composed by two phases with different stoichiometry. In addition, the sample prepared with calcium alone shows the aragonite phase. The microstructure of the magnesium-containing samples is composed of nanocrystals, which are aggregated in spherical particles whereas the aragonite sample presents a typical rod-like morphology. The multicycle tests carried out under CaL-CCS conditions show that an increase on the MgO content in the calcined samples results in a reduced value of effective conversion when compared to aragonite. On the other hand, under CaL-CSP conditions, the samples with the higher MgO content exhibit nearly stable effective conversion values around 0.5 after 20 cycles, which improve the results obtained for aragonite and those reported for natural dolomite tested under the same conditions.


Abril, 2024 | DOI: 10.1016/j.envres.2024.118119

Materiales y Procesos Catalíticos de Interés Ambiental y Energético

MoS2 2D materials induce spinal cord neuroinflammation and neurotoxicity affecting locomotor performance in zebrafish

Di Mauro, G; González, VJ; Bambini, F; Camarda, S; Prado, E; Holgado, JP, Vázquez, E; Ballerini, L; Cellot, G
Nanoscale Horizons, 9(5)(2024) 785-798

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MoS2 nanosheets belong to an emerging family of nanomaterials named bidimensional transition metal dichalcogenides (2D TMDCs). The use of such promising materials, featuring outstanding chemical and physical properties, is expected to increase in several fields of science and technology, with an enhanced risk of environmental dispersion and associated wildlife and human exposures. In this framework, the assessment of MoS2 nanosheets toxicity is instrumental to safe industrial developments. Currently, the impact of the nanomaterial on the nervous tissue is unexplored. In this work, we use as in vivo experimental model the early-stage zebrafish, to investigate whether mechano-chemically exfoliated MoS2 nanosheets reach and affect, when added in the behavioral ambient, the nervous system. By high throughput screening of zebrafish larvae locomotor behavioral changes upon exposure to MoS2 nanosheets and whole organism live imaging of spinal neuronal and glial cell calcium activity, we report that sub-acute and prolonged ambient exposures to MoS2 nanosheets elicit locomotor abnormalities, dependent on dose and observation time. While 25 μg mL−1 concentration treatments exerted transient effects, 50 μg mL−1 ones induced long-lasting changes, correlated to neuroinflammation-driven alterations in the spinal cord, such as astrogliosis, glial intracellular calcium dysregulation, neuronal hyperactivity and motor axons retraction. By combining integrated technological approaches to zebrafish, we described that MoS2 2D nanomaterials can reach, upon water (i.e. ambient) exposure, the nervous system of larvae, resulting in a direct neurological damage.


Abril, 2024 | DOI: 10.1039/d4nh00041b

Materiales Avanzados

Preparation of Geopolymeric Materials from Industrial Kaolins, with Variable Kaolinite Content and Alkali Silicates Precursors

Martínez-Martínez, S; Bouguermouh, K; Bouzidi, N; Mahtout, L; Sánchez-Soto, PJ; Pérez-Villarejo, L
Materials, 17 (2024) 1839

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In the present work, the development of geopolymeric materials with Na or K based on industrial kaolin samples, with variable kaolinite content and alkaline silicates, is studied. XRF, XRD, FTIR and SEM-EDS have been used as characterization techniques. Three ceramic kaolin samples, two from Algeria and one from Charente (France), have been considered. In particular, chemical and mineralogical characterization revealed elements distinct of Si and Al, and the content of pure kaolinite and secondary minerals. Metakaolinite was obtained by grinding and sieving raw kaolin at 80 mu m and then by thermal activation at 750 degrees C for 1 h. This metakaolinite has been used as a base raw material to obtain geopolymers, using for this purpose different formulations of alkaline silicates with NaOH or KOH and variable Si/K molar ratios. The formation of geopolymeric materials by hydroxylation and polycondensation characterized with different Si/Al molar ratios, depending on the original metakaolinite content, has been demonstrated. Sodium carbonates have been detected by XRD and FTIR, and confirmed by SEM-EDS, in two of these geopolymer materials being products of NaOH carbonation.


Abril, 2024 | DOI: 10.3390/ma17081839

Materiales de Diseño para la Energía y Medioambiente

Direct Laser Writing: From Materials Synthesis and Conversion to Electronic Device Processing

Pinheiro, T; Morais, M; Silvestre, S; Carlos, E; Coelho, J; Almeida, HV; Barquinha, P; Fortunato, E; Martins, R
Advanced Materials, 36 (2024) 26

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Direct Laser Writing (DLW) has been increasingly selected as a microfabrication route for efficient, cost-effective, high-resolution material synthesis and conversion. Concurrently, lasers participate in the patterning and assembly of functional geometries in several fields of application, of which electronics stand out. In this review, recent advances and strategies based on DLW for electronics microfabrication are surveyed and outlined, based on laser material growth strategies. First, the main DLW parameters influencing material synthesis and transformation mechanisms are summarized, aimed at selective, tailored writing of conductive and semiconducting materials. Additive and transformative DLW processing mechanisms are discussed, to open space to explore several categories of materials directly synthesized or transformed for electronics microfabrication. These include metallic conductors, metal oxides, transition metal chalcogenides and carbides, laser-induced graphene, and their mixtures. By accessing a wide range of material types, DLW-based electronic applications are explored, including processing components, energy harvesting and storage, sensing, and bioelectronics. The expanded capability of lasers to participate in multiple fabrication steps at different implementation levels, from material engineering to device processing, indicates their future applicability to next-generation electronics, where more accessible, green microfabrication approaches integrate lasers as comprehensive tools.
This review covers recent progress and breakthroughs in direct laser writing for multimaterial synthesis and conversion, toward processing and fabrication of electronics. Predominant laser-material processing mechanisms for the writing of conductive and semiconductive materials are discussed, alongside important considerations on laser operation and implementation for both rigid and flexible electronics, including microelectronics, energy harvesting and storage, sensors, and bioelectronics. image


Abril, 2024 | DOI: 10.1002/adma.202402014

Materiales Ópticos Multifuncionales

Exciton-carrier coupling in a metal halide perovskite nanocrystal assembly probed by two-dimensional coherent spectroscopy

Rojas-Gatjens, E; Tiede, DO; Koch, KA; Romero-Perez, C; Galisteo-López, JF; Calvo, ME; Míguez, H; Kandada, ARS
Journal of Physics-Materials, 7 (2024) 025002

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The surface chemistry and inter-connectivity within perovskite nanocrystals play a critical role in determining the electronic interactions. They manifest in the Coulomb screening of electron-hole correlations and the carrier relaxation dynamics, among other many-body processes. Here, we characterize the coupling between the exciton and free carrier states close to the band-edge in a ligand-free formamidinium lead bromide nanocrystal assembly via two-dimensional coherent spectroscopy. The optical signatures observed in this work show: (i) a nonlinear spectral lineshape reminiscent of Fano-like interference that evidences the coupling between discrete electronic states and a continuum, (ii) symmetric excited state absorption cross-peaks that suggest the existence of a coupled exciton-carrier excited state, and (iii) ultrafast carrier thermalization and exciton formation. Our results highlight the presence of coherent coupling between exciton and free carriers, particularly in the sub-100 femtosecond timescales.


Abril, 2024 | DOI: 10.1088/2515-7639/ad229a

 

 

 

 

 

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