Menú secundario

Scientific Papers in SCI



2023


Nanotecnología en Superficies y Plasma - Materiales Nanoestructurados y Microestructura

Plasmas and acoustic waves to pattern the nanostructure and chemistry of thin films

Rico, V; Regodon, GF; Garcia-Valenzuela, A; Alcaide, AM; Oliva-Ramirez, M; Rojas, TC; Alvarez, R; Palomares, FJ; Palmero, A; Gonzalez-Elipe, AR
Acta Materialia, 255 (2023) 119058

In this work, piezoelectric AWs and plasmas have been brought together during the growth of a thin film as a novel methodology of plasma-assisted thin film structuration. The ensuing effects have been investigated on a model system where SiO2 and SiOx (x<2) thin films have been deposited by magnetron sputtering at oblique angles (MS-OAD) on an electro-acoustically excited LiNbO3 piezoelectric substrate under resonant conditions. The microstructure of the resulting films was 2D patterned and depicted submillimeter size intermingled zones with different optical characteristics, compositions (SiO2 and SiOx) and porosity, from highly porous to dense and compact regions. The 2D nanostructural pattern mimics the AW distribution and has been accounted for by means of a specific simulation model. It is concluded that the morphological and chemical film pattern replicates the distribution of polarization potential on the surface of the AW activated substrate immersed in the plasma. Moreover, we show that the main mechanism responsible for the appearance of domains with different morphology and chemical composition is the focused impingement of Ar+plasma ions on certain regions of the substrate. The general character of this patterning process, the underlying physics and its possibilities to tailor the composition and microstructure of dielectric thin film materials are discussed.


August, 2023 | DOI: 10.1016/j.actamat.2023.119058

Química de Superficies y Catálisis

New 3D Printing Strategy for Structured Carbon Devices Fabrication

Delgado-Martin, G; Rodriguez, N; Dominguez, MI; Agamez-Pertuz, YY; Tejada, MM; Ruiz-Lopez, E; Ivanova, S; Centeno, MA
Catalysts, 13 (2023) 1039

This work shows a new method for the preparation of 100% carbon-structured devices. The method is based on resorcinol-formaldehyde polymerization, using starch as a binder with the addition of a certain amount of external carbon source before polymerization. Molds obtained by 3D printing are used to shape the structured devices in the desired shape, and the ultimate pyrolysis step consolidates and produces the carbonaceous devices. The proposed method allows obtaining supports with different textural and surface properties varying the carbonaceous source, the solvent, or the pyrolysis conditions, among other factors. The as-obtained devices have demonstrated their usefulness as palladium supports for the gas-phase formic acid dehydrogenation reaction. The monolith shows a high conversion of formic acid (81% according to H-2 production) and a high selectivity towards hydrogen production at mild temperatures (80% at 423 K).


July, 2023 | DOI: 10.3390/catal13071039

Reactividad de Sólidos

Thermochemical energy storage using calcium magnesium acetates under low CO2 pressure conditions

Amghar, N; Jimenez, PES; Maqueda, LAP; Perejon, A
Journal of Energy Storage, 63 (2023) 106958

The calcium looping multicycle performance of CaO-based materials, derived from calcium magnesium acetates with different Mg content were tested under experimental conditions compatible with thermochemical energy storage. In order to reduce the sintering-induced decay in performance, calcination at an absolute CO2 pressure of 0.1 bar and 0.01 bar is implemented. CaO carbonation is performed at standard 1 bar CO2 conditions. The samples can be fully calcined in short residence times. Samples with MgO present high cycling stability, even when the MgO content is as low as 5 mol%. The effective conversion values lie within the range 0.88-0.84 over ten calcination/carbonation cycles, which provides an accumulated energy storage density of 90.9 GJ/m3. This outstanding reactivity is related with the microstructure of the sample after calcination composed of CaO nanoparticles that are highly reactive for carbonation.


July, 2023 | DOI: 10.1016/j.est.2023.106958

Nanotecnología en Superficies y Plasma

Setting a comprehensive strategy to face the runback icing phenomena

Mora, J et al.
Surface & Coatings Technology, 465 (2023) 129585

The development of anti-icing robust surfaces is a hot topic nowadays and particularly crucial in the aeronautics or wind energy sectors as ice accretion can compromise safety and power generation efficiency. However, the current performance of most anti-icing strategies has been proven insufficient for such demanding applications, particularly in large unprotected zones, which located downstream from thermally protected areas, may undergo secondary icing. Herein, a new testing methodology is proposed to evaluate accretion mechanisms and secondary icing phenomena through, respectively, direct impact and running-wet processes and systematically applied to anti-icing materials including commercial solutions and the latest trends in the state-of-the-art. Five categories of materials (hard, elastomeric, polymeric matrix, SLIPS and superhydrophobic) with up to fifteen formulations have been tested. This Round-Robin approach provides a deeper understanding of anti-icing mechanisms revealing the strengths and weaknesses of each material. The conclusion is that there is no single passive solution for anti-ice protection. Thus, to effectively protect a given real component, different tailored materials fitted for each particular zone of the system are required. For this selection, shape analysis of such a component and the impact characteristics of water droplets under real conditions are needed as schematically illustrated for aeronautic turbines.


July, 2023 | DOI: 10.1016/j.surfcoat.2023.129585

Materiales Ópticos Multifuncionales

Ultrapure Green High Photoluminescence Quantum Yield from FAPbBr3 Nanocrystals Embedded in Transparent Porous Films

Romero-Pérez, C; Delgado, NF; Herrera-Collado, M; Calvo, ME; Míguez, H (Mig
Chemistry of Materials, 35 (2023) 5541-5549

Achieving highly transparent and emissive films based on perovskite quantum dots (PQDs) is a challenging task since their photoluminescence quantum yield (PLQY) typically drops abruptly when they are used as building blocks to make a solid. In this work, we obtain highly transparent films containing FAPbBr(3) quantum dots that display a narrow green emission (lambda = 530 nm, full width at half-maximum (FWHM) = 23 nm) with a PLQY as high as 86%. The method employed makes use of porous matrices that act as arrays of nanoreactors to synthesize the targeted quantum dots within their void space, providing both a means to keep them dispersed and a protective environment. Further infiltration with poly(methyl methacrylate) (PMMA) increases the mechanical and chemical stability of the ensemble and serves to passivate surface defects, boosting the emission of the embedded PQD and significantly reducing the width of the emission peak, which fulfills the requirements established by the Commission Internationale de l'E ' clairage (CIE) to be considered an ultrapure green emitter. The versatility of this approach is demonstrated by fabricating a color-converting layer that can be easily transferred onto a light-emitting device surface to modify the spectral properties of the outgoing radiation.


July, 2023 | DOI: 10.1021/acs.chemmater.3c00934

Química de Superficies y Catálisis

Effect of noble metal addition over active Ru/TiO2 catalyst for CO selective methanation from H2 rich- streams

Bobadilla, LF; Muñoz-Murillo, A; Gandara-Loe, J; Perez, A; Laguna, OH; Martinez, TLM; Penkova, A; Centeno, MA; Odriozola, JA
International Journal of Hydrogen Energy, 48 (2023) 25065-25074

Selective CO methanation from H2-rich stream has been regarded as a promising route for deep removal of low CO concentration and catalytic hydrogen purification processes. This work is focused on the development of more efficient catalysts applied in practical conditions. For this purpose, we prepared a series of catalysts based on Ru supported over titania and promoted with small amounts of Rh and Pt. Characterization details revealed that Rh and Pt modify the electronic properties of Ru. The results of catalytic activity showed that Pt has a negative effect since it promotes the reverse water gas shift reaction decreasing the selectivity of methanation but Rh increases remarkably the activity and selectivity of CO methanation. The obtained results suggest that RuRh-based catalyst could become important for the treatment of industrial-volume streams.


July, 2023 | DOI: 10.1016/j.ijhydene.2022.07.072

Reactividad de Sólidos

R-curve evaluation of 3YTZP/graphene composites by indirect compliance method

Lopez-Pernia, C; Munoz-Ferreiro, C; Prada-Rodrigo, J; Moreno, P; Reveron, H; Chevalier, J; Morales-Rodriguez, A; Poyato, R; Gallardo-Lopez, A
Journal of the European Ceramic Society, 43 (2022) 3486-3497

This work addresses the crack growth resistance of 3 mol% Yttria-doped Tetragonal Zirconia Polycrystalline (3YTZP) spark-plasma sintered (SPS) composites containing two types of graphene-based nanomaterials (GBN): exfoliated graphene nanoplatelets (e-GNP) and reduced graphene oxide (rGO). The crack growth resistance of the composites is assessed by means of their R-Curve behavior determined by three-point bending tests on single edge "V" notched beams (SEVNB), in two different orientations of the samples: with the crack path perpendicular or parallel to the pressure axis during the SPS sintering. The sharp edge notches were machined by ultrashort laser pulsed ablation (UPLA). The compliance and optical-based methods for evaluating the crack length are compared on the basis of the experimental R-Curve results in composites with 2.5 vol% rGO tested in the perpendicular orientation. Moreover, the activation of reinforcement mechanisms is evaluated by both the fracture surface inspection by Scanning Electron Microscopy and a compliance analysis. It is shown that the indirect compliance method is relevant and reliable for calculating the R-Curve of 3YTZP/GBN composites. The effect of the type and content of GBN on the crack growth resistance of the composites is also discussed.


July, 2023 | DOI: 10.1016/j.jeurceramsoc.2023.02.002

Fotocatálisis Heterogénea: Aplicaciones

ZnO/TiO2 and ZnO/Nb2O5 as effective systems for the treatment of enteric bacteria and commercial dyes

Hernandez, JS; Murcia, JJ; Rojas, H; Hidalgo, MC; Navio, JA
Revista Facultad de Ingeniería-Universidad de Antioquia, 108 (2023) 9-17

In this study, ZnO/TiO2 and ZnO/Nb2O5 photocatalysts were evaluated in the river pollution remediation and wastewater treatment from textile factories, thus, the target pollutants selected for this study were enteropathogenic bacteria and commercial dyes. The mixed oxide systems were extensively analyzed in order to explore their physicochemical properties. From this analysis, it was found that the coupling of two oxides did not modify the crystallinity of the pristine semiconductors. As a result, XRD Wurtzite phase, hexagonal phase, and anatase phases were identified for ZnO, Nb2O5, and TiO2 photocatalyst, respectively. Using UV-Vis DRS, a higher absorption for mixed oxides in the visible region of the electromagnetic spectrum was observed, along with a decrease in the band gap value in these materials. The results of the photocatalytic activity evaluation showed that the coupling of ZnO with Nb2O5 and TiO2 increased the effectiveness of the total organic carbon (TOC) and E. Coli elimination. 83% of TOC and elimination of 64% of E. coli were achieved using ZnO/Nb2O5 photocatalyst for the treatment of water samples from the polluted river.


July, 2023 | DOI: 10.17533/udea.redin.20220785

Nanotecnología en Superficies y Plasma

Dielectric multilayers for broadband optical rotation enhancement

Pellegrini, G; Mogni, E; Gil-Rostra, J; Yubero, F; Fossati, S; Dostálek, J; Vázquez, RM; Osellame, R; Celebrano, M; Finazzi, M; Biagioni, P
Nuovo Cimento C-Colloquia and Communications in Physics, 46 (2023) 111

We design a simple dielectric multilayer capable of sustaining broadband superchiral surface waves. We show that the platform can produce large optical chirality enhancements in a wavelength range of hundreds of nanometers. We finally demonstrate that these properties result in the enhancement of the optical rotation signal well above two orders of magnitude, thus extending surface-enhanced chiral spectroscopies beyond the traditionally addressed circular dichroism signals.


July, 2023 | DOI: 10.1393/ncc/i2023-23111-1

Reactividad de Sólidos

An overview of polymeric composite scaffolds with piezoelectric properties for improved bone regeneration

Donate, R; Paz, R; Moriche, R; Sayagués, MJ; Alemán-Domínguez, ME; Monzón, M
Materials & Design, 231 (2023) 112085

 

Despite the dramatic change that Tissue Engineering or stem cell therapies have brought to current therapeutic strategies, there is a lack of functionalities in the available biomaterials for manufacturing scaffolds to treat several highly prevalent osseous diseases (osteochondral defects, osteoporosis, etc.). One promising approach to fill this gap involves the development of innovative piezoelectric scaffolds for improved bone regeneration. Scaffolds with the appropriate piezoelectricity can positively influence the proliferation and differentiation of mesenchymal stem cells to regenerate bone tissue, since surface electrical charges play a key role in the mechanotransduction process. In this work, polymeric-based composite scaffolds with piezoelectric properties intended for bone tissue engineering are reviewed. Special attention is paid to biocompatible, piezoelectric polymers that show suitable properties to be pro-cessed by additive manufacturing techniques. Previous works on composite scaffolds based of these poly-meric matrices and containing piezoceramic additives are summarized. The use of piezoelectric nanostructured composite formulations containing lead-free ceramic oxide nanoparticles with per-ovskite structure is highlighted. Also, different commonly applied mechanical stimuli to activate the piezoelectric effect of the developed materials are presented. Finally, other applications of such scaffolds are mentioned, including their capabilities for real-time monitoring


July, 2023 | DOI: 10.1016/j.matdes.2023.112085 | Digital CSIC: http://hdl.handle.net/10261/355426

 

 

 

 

 

icms