Resultados de investigación

Plasma electrolytic oxidation (PEO) has been targeted as an eco-friendly alternative technology to conventional chromic acid anodizing (CAA) for corrosion protection of aluminium alloys in the aircraft industry. However, conventional PEO technology implies high energy consumption. Flash-PEO coatings (≤10 μm) produced in short treatment times (≤ 5 min) constitute a feasible way to overcome this limitation. Nevertheless, the long-term corrosion resistance is compromised, thus requiring novel sealing post-treatments. The present work studies the effect of stand-alone hybrid sol-gel (HSG) and Ce-doped hybrid sol-gel (HSG-Ce) coatings as a sealing post-treatment to evaluate the long-term corrosion resistance of Flash-PEO coatings on aluminium alloy (AA) 2024-T3. The characterization of the PEO, HSG, and HSG-Ce coatings was performed by scanning electron microscopy, X-ray diffraction, water contact angle, dry adhesion tests (ISO 2409), optical profilometry and Fourier transform infrared spectroscopy. The corrosion behaviour was assessed by electrochemical impedance spectroscopy up to 21 days (3.5 wt% NaCl). Active corrosion protection was assessed by immersion tests of artificially scratched coatings. Present findings reveal that low-energy-cost Flash-PEO coatings were successfully formed on AA2024-T3 alloy. Both HSG and HSG-Ce coatings were homogeneously formed on Flash PEO coating. Regarding the corrosion resistance, HSG-Ce showed significant scratch protection during 21 days of immersion in 3.5 wt% NaCl. The results suggest that, while the release of Si and Ce from the coating provided corrosion protection, nitrate release promoted localized corrosion phenomena in the scribe. This was associated with the preferential pitting corrosion phenomena at the Cu-rich intermetallic compounds instead of forming a thick and stablenitrate-rich passive layer.

The objective of this work is to understand the plasma electrolytic oxidation (PEO) treatment and electrochemical behaviour of a Ti6Al4V alloy manufactured by a laser powder bed fusion additive manufacturing (AM) technique known as direct metal laser sintering (DMLS). Ca and P-containing coatings were produced with short time (<120 s) PEO treatments (also termed as Flash-PEO) obtaining 3–10 μm-thick coatings on both the AM alloy and a conventional counterpart. Subsequently, the electrochemical behaviour of the bare and treated alloys was assessed in a modified α-MEM solution via potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The fine α-lamellar microstructure of the AM alloy with small β-phase particles at the interlamellar spaces was seen to advance the onset of sparking promoting faster growth of PEO coating in comparison to the conventional alloy. Flash-PEO coatings enhanced the corrosion protection of both conventional and AM alloys, the thinnest (<3 μm) coatings providing up to three times greater protection. AM Ti6Al4V was found to be susceptible to localized crevice corrosion which could be assigned to the high grain boundary density. Flash-PEO treatments, even as short as 35 s, were sufficient to successfully prevent it.

The corrosion resistance of AZ31B magnesium alloy was evaluated after a two-step surface treatment consisting of a permanganate–fluorozirconate conversion layer followed by Flash-PEO in a silicate–fluoride (SiF) electrolyte. Electrochemical tests after 24 hours immersion in 0.5 wt.% NaCl demonstrated that the structured coating reduced the corrosion rate when compared to the reference Flash-PEO SiF coating ((3.4 ±1.0)x10-6 mm·yr-1 versus (1.3±0.8)x10-5 mm·yr-1). After 72 hours, this trend persisted, with impedance values at low frequency one order of magnitude higher than its counterpart without precursor layer ((1.4±1.0)x107 Ω·cm2 versus (2.6±1.0)x106 Ω·cm2). Notably, Flash-PEO coatings in both cases preserved electrochemical integrity even in the presence of pre-existing surface defects. The permanganate–fluorozirconate precursor layer promoted, after Flash-PEO processing, a distinctive “coral reef-like” morphology with reduced interconnected porosity, thereby enhancing barrier properties by limiting substrate exposure to the corrosive environment. Complementary characterization confirmed the incorporation of zirconium and manganese species, along with compounds typically derived from the Flash-PEO SiF electrolyte.

Experimental data of of the project FishFedEx (Effects of microplastics in goldfish)

Conjunto de datos utilizados durante la investigación que lleva a la tesis doctoral De los códices diplomáticos denominados Becerros. Estudio y propuesta de corpus digital

Vídeo impresión 3D prisma T-ORG-6. Adjunto de la Tesis Doctoral titulada: "Formulación de ionogeles e hidrogeles de celulosa procedente del fraccionamiento de la madera y su aplicación en la impresión 3D" de Cynthia Hopson.

Esta cartografía o visualización relacional de datos forma parte de la investigación "Nuevas estéticas energéticas desde el arte", publicada en versión de capítulo de libro colectivo, con título "Estéticas", y un archivo/web con título homónimo. La cartografía muestra 41 proyectos artísticos que abordan las consecuencias ecosistémicas de la petrodependencia constitutiva de la modernidad y de nuestra ecodependencia energética contemporánea. Prácticas que no solo critican la herencia fósil, sino que además proponen nuevas estéticas en torno a las problemáticas energéticas. Esta investigación es producto del proyecto «Humanidades energéticas. Energía e imaginarios socioculturales entre la Revolución industrial y la crisis ecosocial» (PID2020-113272RA-100, HUMENERGE), financiado por MICIU/AEI /10.13039/501100011033. La investigación ha sido llevada a cabo por Bárbara Fluxá (coord.ª), Santiago Morilla, Jorge Yeregui y Coco Moya, integrantes del Taller permanente de investigación artística del proyecto. Para más información sobre la investigación y la cartografía consulte el archivo/web: https://esteticafosil.csic.es/nuevas-esteticas-energeticas/

Base de datos SUMMA Signum. Estructura y datos de investigación utilizados durante el proyecto de investigación: El castellano norteño en la Edad Media. Estudio Lingüístico de la documentación palentina. Ministerio de Economía, Industria y Competitividad. FFI 2016-80230P

Encapsulating hydrophobic nanoparticles (NPs) with a hydrophilic silica shell has proven critical for expanding their applicability to aqueous media, favoring their incorporation into composite materials, and tunning their surface properties (specific surface, thickness and spacing) during the design of nano/micro systems. However, a generalized, scalable method that achieves simultaneous control over both shell thickness and applicability across chemically diverse core materials remains a significant synthetic challenge. Here, we present a versatile and scalable methodology for robustly coating various hydrophobic core materials with a silica shell of precisely tunable thickness. Our approach integrates an efficient ligand-exchange procedure, utilizing nitrosonium tetrafluoroborate (NOBF4) to substitute surface oleate ligands with weakly coordinating anions, thereby enabling phase transfer to N,N-Dimethylformamide (DMF). This hydrophilic intermediate is then directly coated using a modified Stöber process. By systematically tuning the NH3/TEOS ratio and the total precursor concentration, we demonstrate precise control over the shell thickness, successfully synthesizing uniform silica coatings ranging from thin (~6 nm) to ultra-thick shells (over 500 nm, yielding total diameters >1 µm) on individual nanoparticles. We validate the versatility of this integrated protocol by applying it to both rare-earth Upconversion Nanoparticles (UCNPs) of varying shapes, crystal phases and sizes, and magnetic Fe3O4 nanoparticles. This robust and reproducible method offers a generalized platform for the high-throughput production of core-shell NP@SiO2 structures with tailored dimensions, which is essential for engineering advanced materials for diverse applications in sensing, catalysis, and composite systems.

This dataset contains the tabular data supporting the analyses presented in the accompanying article on LiDAR-informed modelling of megalithic landscape densities. It includes results derived from two case studies, integrating megalithic site inventories (WIMD) with CORINE Land Cover data to characterise land-use contexts, spatial distributions, and density-related metrics. Separate tables are provided for each case study and data source. The dataset is intended to ensure transparency and reproducibility of the analytical results reported in the article "Reassessing megalithic densities in Southwestern Iberia through LiDAR-based landscape analysis" and may be reused for comparative or methodological purposes in other archaeological landscape studies.