Articles publicats en revistes (Ciència dels Materials i Química Física)

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Biotemplating of Metal–Organic Framework Nanocrystals for Applications in Small-Scale Robotics
(Wiley-VCH, 2021-12-07) Terzopoulou, Anastasia; Palacios-Corella, Mario; Franco, Carlos; Sevim, Semih; Dysli, Thomas; Mushtaq, Fajer; Romero-Angel, María; Martí-Gastaldo, Carlos; Gong, De; Cai, Jun; Chen, Xiang-Zhong; Pumera, Martin; deMello, Andrew J.; Nelson, Bradley J.; Pané, Salvador; Puigmartí-Luis, Josep
Biotemplating is a powerful approach for manufacturing small-scale devices. Here, the assembly of metal-organic framework (MOF) nanocrystals onto biotemplated magnetic helical structures on the cyanobacterium Spirulina platensis is reported. It is demonstrated that the authors' approach is universal and can be used to equip biotemplated structures with different functional MOF systems. The successful assembly of MOF nanocrystals on magnetically coated helical biotemplates is achieved by decorating the magnetic surface with gelatin, a naturally occurring macromolecule with synthon moieties that allows anchoring of the MOF nanocrystals via electrostatic interactions. Furthermore, as gelatin is a thermally responsive material, it can serve to free the magnetic biotemplates from the MOF nanocrystal cargoes. As such, the systems can be used as highly integrated magnetically driven microrobots with multiple functionalities. To this end, the potential of these composite helical architectures is demonstrated as MOF-based small-scale robots with applications in biomedicine and environmental remediation.
A critical review over the electrochemical disinfection of bacteria in synthetic and real wastewaters using a boron-doped diamond anode
(Elsevier, 2021-08-01) Martínez-Huitle, Carlos Alberto; Brillas, Enric
Inadequate access to clean water and sanitation are the most relevant problems afflicting developing and industrialized nations. Global water scarcity is expected to grow worse in the coming decades and this has motivated the scientific community to identify new, safe, and robust water disinfection technologies at lower cost and with less energy, diminishing the use of chemicals and impact on the environment. Usually, conventional methods of water treatment can solve this problem satisfactorily, such as chlorination, but, sometimes, they can be chemically, energetically, and operationally intensive. Therefore, the science and technology has encouraged the development of other alternative disinfection technologies. In this frame, electrochemical disinfection or electrodisinfection is currently experiencing a renaissance due to the tremendous contributions of novel electrocatalytic materials as well as the use of electric current as an inexpensive and suitable reagent to drive the inactivation of waterborne pathogens, avoiding conventional chemical oxidizers or reducing agents. Electrodisinfection has a significant technical impact, because it can be easily scaled up or design small–portable devices, benefiting from advantages such as versatility, environmental compatibility, automation, inherent safety, and potential cost effectiveness among others. Diamond films emerge as a novel and sustainable solution to electrogenerate powerful oxidants for effectively controlling waterborne pathogens in drinking water. The overarching goal of this critical review is to evidence the importance of diamond electrochemical methods as alternative for the eradication of waterborne infectious agents from public and drinking waters. The mechanisms of bacteria inactivation, and the fundamentals and applications of electrochemical oxidation with diamond to disinfect synthetic and real waters and wastewaters are exhaustively discussed. The use of hybrid and sequential processes involving electrochemical oxidation with other techniques, as well as endodontic and food control applications, are also analyzed. A section remarking the future challenges of electrodisinfection with diamond is finally presented.
Synthesis of 2D porous crystalline materials in simulated microgravity
(Wiley-VCH, 2021-06-04) Contreras-Pereda, Noemí; Rodríguez-San-Miguel, David; Franco, Carlos; Sevim, Semih; Vale, João Pedro; Solano, Eduardo; Fong, Wye-Khay; Giudice, Alessandra Del; Galantini, Luciano; Pfattner, Raphael; Pané, Salvador; Sotto Mayor, Tiago; Ruiz-Molina, Daniel; Puigmartí-Luis, Josep
To date, crystallization studies conducted in space laboratories, which are prohibitively costly and unsuitable to most research laboratories, have shown the valuable effects of microgravity during crystal growth and morphogenesis. Herein, an easy and highly efficient method is shown to achieve space-like experimentation conditions on Earth employing custom-made microfluidic devices to fabricate 2D porous crystalline molecular frameworks. It is confirmed that experimentation under these simulated microgravity conditions has unprecedented effects on the orientation, compactness and crack-free generation of 2D porous crystalline molecular frameworks as well as in their integration and crystal morphogenesis. It is believed that this work will provide a new 'playground' to chemists, physicists, and materials scientists that desire to process unprecedented 2D functional materials and devices.
Recycling of Plastics in the Automotive Sector and Methods of Removing Paint for Its Revalorization: A Critical Review
(MDPI, 2024-10-28) Zambrano Membrives, Carla; Tamarit, Pablo; Fernández Renna, Ana Inés; Barreneche, Camila
The presence of plastics in the automotive industry is increasingly significant due to their lightweight nature, which contributes to reducing fuel consumption and CO2 emissions while improving versatility and mechanical properties. Polypropylene (PP) and other polyolefins are among the most commonly used materials, especially for components such as bumpers. The use of composite materials, i.e., a combination of different polymers, improves the properties through synergistic effects, thereby also improving the performance of the final product. In the automotive industry, PP reinforced with 20% talc or CaCO3 is commonly used. The mechanical recycling of polypropylene bumpers is the most common type of recycling. However, challenges arise during this process, such as the presence of impurities like paint, chemical contaminants from previous use, and polymeric impurities from different polymers mixed into the polymer matrix, among others. Paint affects both the aesthetic quality and the mechanical and intrinsic properties of the recycled material. This review aims to analyze the main methods reported in the literature, focusing on those with low environmental impact. Furthermore, these methods are classified according to their capacity, effectiveness, substrate damage, environmental hazards, and economic feasibility. It also aims to offer a comprehensive overview of the mechanical recycling of plastic waste in the automotive industry.
Discrete Element Method Optimization Simulation of Planetary Ball Mills Operating Conditions
(AIDIC-The Italian Association of Chemical Engineering, 2024-12-30) Cabello, Rúben; Han, Jingli; Plesu Popescu, Alexandra Elena; Bonet i Ruiz, Jordi; Clave, Genís; Barreneche, Camila; Dosta Parras, Sergi
Planetary mills have garnered significant attention in various fields of material science, nanotechnology, and engineering due to their ability to finely grind and mix materials at the nanoscale. The study of such mills is often performed by using empirical approaches for the optimization of experimental conditions. Modeling is possible based on simple physics involving the interaction of DEM (Discrete Element Method) simulations, offering the possibility of studying planetary mills with a much deeper understanding of the process. This study focuses on the numerical characterization of planetary ball mills in terms of different parameters such as angular velocity, number of balls, and ball size. The influence of such parameters on the energy spectra of the mill is then found via DEM simulation, which is very useful information for modeling the breakage or adhesion processes inside a mill or scaling up such experimental mills to industrial processes. Results show that from all the useful power, 65.4 % and 54.0 % go into ball-wall shearing collisions for both 1 cm and 0.3 cm balls. At around 0.5 cm balls, there seems to be a minimum as only 46.7 % goes into ball-wall shear collisions. Despite this, those types of collisions take more power than any other for all the cases studied, being a ball size that is closer to the optimal value. This research, then, acts as a bridge between lab-scale conditions, which are easier and more cost-effective to optimize, and large-scale production, where optimization tends to be costly and difficult. The presentstudy provides an understanding of the tools required to produce novel nanomaterials
Operando XPS and NEXAFS to link the OER mechanism with the fast electro-oxidation of organic pollutants on a porous NiMnO3–rGO anode
(Royal Society of Chemistry, 2025-10-30) Mirehbar, K.; Kumar, Samika; Sirés Sadornil, Ignacio; Sánchez, J.S.; Held, Georg; Palma, J.; Lado, J.J.
Electro-oxidation is one of the most promising and eco-friendly technologies for water decontamination. However, its industrial application is still limited by the high cost, poor faradaic efficiency, low durability, and potential toxicity of common high-power oxidation anodes. These challenges have been addressed by developing a novel composite comprising a mixed metal oxide (NiMnO3) and reduced graphene oxide (rGO). The NiMnO3–rGO anode allowed the fast and complete removal of phenol. Among different highly porous substrates, graphite felt (GF) led to the highest energy efficiency, since the GF/ NiMnO3–rGO anode yielded 100% phenol removal within only 30 min at a current density as low as 10 mA cm−2, which was accompanied by 85% COD removal at 120 min. This anode demonstrated excellent stability, maintaining 100% phenol removal efficiency across five consecutive cycles while also showing low energy consumption (60–65 Wh (kg COD)−1). Operando X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) analysis provided mechanistic insights. It is demonstrated that rGO shifts the *OH production pathway towards the lattice oxygen mechanism (LOM), in contrast to the adsorbate evolution mechanism (AEM) observed for NiMnO3 alone. This mechanistic shift supports the enhanced stability and sustained electrocatalytic activity, contributing to the high performance of the GF/ NiMnO3–rGO composite anode in the context of a more sustainable technology for treating organic contaminants.
Molecular dynamics simulation of temperature and concentration distribution at liquid-gas interface during liquid air storage process
(Elsevier, 2025-06-01) You, Zhanping; Cheng, Menghan; Ma, C.; Xiao, Yufei; Zhao, Xuemin; Barreneche, Camila; She, X.
To address global challenge of climate changes, renewable energy has been fully developed in recent years. However, renewable energy is usually intermittent which makes it challenging for application. Liquid air energy storage can effectively store intermittent energy with promising prospects. Liquid air is a mixture composed of N2, O2 and Ar with different evaporation temperatures. It is assumed to form temperature and concentration stratification during storage and thus causes safety challenge. To address this issue, molecular dynamics (MD) simulation method is used to study the temperature and concentration distribution characteristics in liquid air. The results show that the system temperature remains constant at 94 K with no temperature stratification during storage. However, the concentration of liquid air changes along vertical direction (z axis): the oxygen concentration remains stable around 21 % as z is 0–60 Å, rises to 22.1 % as z is from 60 to 70 Å and drops to 0 % as z is above 80 Å. The thin and short stratification phenomenon occurs at the gas-liquid interface region. In addition, a higher heat flux leads to a higher evaporation rate and a larger oxygen concentration. As the heat flux increases from 0.0 to 2.4 W/m2, evaporation rate rises from 0.13 to 0.2 % and the oxygen concentration at the liquid-gas interface reaches 22.3 %. Thus, concentration stratification exists during liquid air storage and should be treated carefully. This paper provides an insight into the temperature and concentration distribution of liquid air during storage and is significant for safety improvement and development of liquid air energy storage
Review on properties, physics, and fabrication of two-dimensional material-based metal-matrix composites (2DMMCs) for heat transfer systems
(Elsevier, 2025-04-23) Lee, Hyojung; Lordejani, Amir Ardeshiri; van Goor, Leonore; Jurov, Andrea; Koutsioukis, Apostolos; Ruan, Siyuan; Santhosh, Neelakandan M.; Zarei, Fatemeh; Barreneche, Camila; Cvelbar, Uroš; Dosta Parras, Sergi; Geurts, Bernard J.; Guagliano, Mario; Jafari, Davoud; Nicolosi, Valeria; Yin, Shuo; Zavašnik, Janez; Bagherifard, Sara; Lupoi, Rocco; Wits, Wessel W.
In the exploration of new materials development, 2D materials have received much attention due to their outstanding properties in terms of e.g. strength, and electrical and thermal conductivities. Graphene and boron nitride, amongst other 2D materials, are renowned for their exceptional thermal conductivity. In this review, we examine the properties, physics, and fabrication techniques of 2D material-based metal-matrix composites (2DMMCs) with a specific focus on heat transfer systems. The on-going demand for better electronic cooling systems in combination with advancements in mass production techniques of 2D materials facilitates the application of 2DMMCs in heat transfer systems. However, currently, the thermal behaviour of 2DMMCs remains largely uncategorized, strengthening the timely context of this review. Next to recent research progress, material properties, production techniques and strategies for improving thermal conductivity of 2DMMCs are addressed in this work. Methods to reliably assess the thermal conductivity of 2D enhanced materials are discussed alongside the fabrication techniques for 2D-material feedstocks for 2DMMCs production. Also, current limitations in the heat transfer capabilities of 2DMMCs, alongside prospects for enhancing thermal properties through emerging technologies, such as additive manufacturing, are addressed.
Paint removal from recycled thermoplastic bumpers and its industrial revalorization in the automotive industry: application of shot blasting technology
(Elsevier, 2025-10-01) Zambrano Membrives, Carla; Fernández Renna, Ana Inés; Tamarit, Pablo; Dosta Parras, Sergi; Barreneche, Camila
The recycling and revalorization of polymeric waste is crucial to manage the large amount generated by the automotive industry. The most common recycling practice for thermoplastics materials is mechanical recycling, based on operations such as collect, separation of contaminations, washing/shredding, dying if required, tumbling with magnet, extrusion, palletisation and injection moulding (in case of exterior parts such as bumpers) [1]. During this process there are challenges that have not yet been solved. In the case of bumpers, superficial paint is observed on used or post-industrial bumpers that have had some defect in the painting process and are rejected. Paint residues negatively impact recycled plastics, creating weak points and compromising properties like thermal stability and mechanical strength [2]. Therefore, removing paint from polymeric waste, particularly bumpers, is crucial for obtaining high-quality recycled materials and a closed loop in automotive industry [3]. The study aims to use metal particle impact technology to efficiently remove acrylic paint from polypropylene substrate whit 20 % talc load in recycled bumpers. The main objectives of the work are (i) to observe the effect of the different test conditions on the effectiveness of removal paint, (ii) to make an approach to the industrial feasibility in a real recycling environment and (iii) to study different treatments for the elimination of the metallic particles left behind by the blasting process. The results show that the angular shot and a combination of 90°/grazing angle of incidence are better than the spherical shot and other angles. To remove these metal particles ultrasonic bath presents the best results among others, but a total elimination of these remains is not obtained.
Comparison of microstructure and mechanical properties of Fe3Al/TiC coatings produced by cold gas spray and high velocity oxygen fuel
(Elsevier B.V., 2025-11-02) Clave, Genís; Betancor, Lorena; Barreneche, Camila; Martín-Vilardell, Anna; Dosta Parras, Sergi
Fe3Al powders reinforced with TiC were synthesized and deposited as coatings using Cold Gas Spraying (CGS) and High-Velocity Oxy-Fuel (HVOF) techniques. Fe3Al intermetallic compounds are known for their excellent resistance to sulfidizing and carburizing environments. However, their mechanical properties can be enhanced through reinforcement with TiC particles. The Fe3Al/TiC feedstock powder was produced via agglomeration and sintering, resulting in a homogeneous distribution of TiC particles around the Fe3Al matrix. Coatings were deposited onto AISI 316L stainless steel substrates and characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), as well as adhesion and erosion tests. The results indicate that CGS coatings exhibit lower oxidation levels, whereas HVOF coatings demonstrate superior adhesion and hardness due to their denser microstructure and greater particle deformation. Hardness increased with the incorporation of TiC. Erosion testing revealed that CGS coatings performed better, attributed to their reduced brittleness compared to HVOF coatings. These findings highlight the potential of Fe3Al/TiC coatings for high-temperature and wear-resistant applications. Moreover, the study demonstrates that comparable performance can be achieved using CGS as with HVOF for depositing Fe3Al/TiC intermetallic coatings.
Cosmic-ray acceleration and escape from supernova remnant W44 as probed by Fermi-LAT and MAGIC
(EDP Sciences, 2025-01-23) Abe, S.; Abhir, J.; Abhishek, A.; Acciari, V. A.; Aguasca Cabot, Arnau; Agudo, I.; Aniello, T.; Ansoldi, S.; Antonelli, L. A.; Arbet-Engels, Axel; Arcaro, C.; Asano, K.; Babić, A.; Baquero, A.; Barres de Almeida, U.; Barrio, J. A.; Batković, I.; Bautista, A.; Baxter, J.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Bernete, J.; Berti, A.; Besenrieder, J.; Bigongiari, C.; Biland, A.; Blanch, O.; Bonnoli, G.; Bošnjak, Ž.; Bronzini, E.; Burelli, I.; Busetto, G.; Campoy-Ordaz, A.; Carosi, A.; Carosi, R.; Carretero-Castrillo, Mar; Castro-Tirado, A.J.; Cerasole, D.; Ceribella, G.; Chai, Yandong; Chilingarian, A.; Cifuentes, A.; Colombo, E.; Contreras, J.L.; Cortina, J.; Covino, S.; D'Amico, G.; D'Elia, V.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Lotto, B.; de Menezes, R.; Del Popolo, A.; Delfino, M.; Delgado, Jordi; Delgado Mendez, C.; Di Pierro, F.; Dominis Prester, D.; Donini, A.; Dorner, D.; Doro, M.; Elsaesser, D.; Emery, G.; Escudero, J.; Fariña, L.; Fattorini, A.; Foffano, L.; Font, L.; Fröse, S.; Fukazawa, Y.; García López, R.J.; Garczarczyk, M.; Gasparyan, S.; Gaug, M.; Giesbrecht Paiva, J.G.; Giglietto, N.; Gliwny, P.; Godinović, N.; Gozzini, Sara Rebecca; Gradetzke, T.; Grau, R.; Green, J.G.; Günther, P.; Hadasch, D.; Hahn, A.; Hassan, T.; Heckmann, L.; Herrera, J.; Hrupec, D.; Hütten, M.; Imazawa, R.; Ishio, K.; Jiménez Martínez, I.; Jormanainen, J.; Kayanoki, T.; Kerszberg, D.; Kluge, G.W.; Kobayashi, Y.; Kouch, P.M.; Kubo, H.; Kushida, J.; Láinez, M.; Lamastra, A.; Leone, F.; Lindfors, E.; Linhoff, L.; Lombardi, S.; Longo, F.; López-Coto, R.; López-Moya, M.; López-Oramas, A.; Loporchio, S.; Lorini, A.; Lyard, E.; Machado de Oliveira Fraga, B.; Majumdar, P.; Makariev, M.; Maneva, G.; Mang, N.; Manganaro, M.; Mangano, S.; Mannheim, K.; Mariotti, M.; Martínez, Manel; Martínez-Chicharro, M.; Mas-Aguilar, A.; Mazin, D.; Menchiari, S.; Mender, S.; Miceli, D.; Miener, T.; Miranda, J.M.; Mirzoyan, R.; Molero González, M.; Molina, Edgar; Mondal, H.A.; Moralejo, A.; Morcuende, D.; Nakamori, T.; Nanci, C.; Nava, L.; Neustroev, V.; Nickel, L.; Nievas Rosillo, M.; Nigro, C.; Nikolić, L.; Nishijima, K.; Njoh Ekoume, T.; Noda, K.; Nozaki, S.; Ohtani, Y.; Okumura, A.; Otero-Santos, J.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, Riccardo; Paredes i Poy, Josep Maria; Peresano, M.; Persic, M.; Pihet, Marine; Pirola, G.; Podobnik, F.; Prada Moroni, P.G.; Prandini, E.; Principe, G.; Priyadarshi, C.; Rhode, W.; Ribó Gomis, Marc; Rico, J.; Righi, C.; Sahakyan, N.; Saito, T.; Satalecka, K.; Saturni, F.G.; Schleicher, B.; Schmidt, K.; Schmuckermaier, F.; Schubert, J.L.; Schweizer, T.; Sciaccaluga, A.; Silvestri, G.; Sitarek, J.; Sliusar, V.; Sobczynska, D.; Spolon, A.; Stamerra, A.; Strišković, J.; Strom, D.; Strzys, M.; Suda, Y.; Suutarinen, S.; Tajima, H.; Takahashi, M.; Takeishi, R.; Temnikov, P.; Terauchi, K.; Terzić, T.; Teshima, M.; Truzzi, S.; Tutone, A.; Ubach, S.; van Scherpenberg, J.; Vazquez Acosta, M.; Ventura, Salvador; Viale, I.; Vigorito, C.F.; Vitale, V.; Vovk, I.; Walter, Rudolf; Will, M.; Wunderlich, Carolin; Yamamoto, T.; Di Tria, R.; Di Venere, L.; Giordano, F.; Bissaldi, E.; Green, D.; Morlino, G.
Context. The supernova remnant (SNR) W44 and its surroundings are a prime target for studying the acceleration of cosmic rays (CRs). Several previous studies established an extended gamma-ray emission that is set apart from the radio shell of W44. This emission is thought to originate from escaped high-energy CRs that interact with a surrounding dense molecular cloud complex. Aims. We present a detailed analysis of Fermi-LAT data with an emphasis on the spatial and spectral properties of W44 and its surroundings. We also report the results of the observations performed with the MAGIC telescopes of the northwestern region of W44. Finally, we present an interpretation model to explain the gamma-ray emission of the SNR and its surroundings. Methods. We first performed a detailed spatial analysis of 12 years of Fermi-LAT data at energies above 1 GeV, in order to exploit the better angular resolution, while we set a threshold of 100 MeV for the spectral analysis. We performed a likelihood analysis of 174 hours of MAGIC data above 130 GeV using the spatial information obtained with Fermi-LAT. Results. The combined spectra of Fermi-LAT and MAGIC, extending from 100 MeV to several TeV, were used to derive constraints on the escape of CRs. Using a time-dependent model to describe the particle acceleration and escape from the SNR, we show that the maximum energy of the accelerated particles has to be ≃40 GeV. However, our gamma-ray data suggest that a small number of lower-energy particles also needs to escape. We propose a novel model, the broken-shock scenario, to account for this effect and explain the gamma-ray emission.
Optimization of Fe3Al intermetallic cold gas spray coatings: Microstructural characterization
(Elsevier B.V., 2025-03-11) Dosta Parras, Sergi; Clave, Genís; Betancor, Lorena; Barreneche, Camila; Martín-Vilardell, Anna
Cold Gas Spray (CGS) is increasingly applied in industry and becoming even more important in advanced applications. This study focuses on the use of CGS process optimization of metal transitional aluminides, specifically Fe3Al. These low-cost materials have high resistance to sulfidation and carburizing atmospheres, as well as excellent oxidation resistance at high temperatures. Therefore, this study aims to deposit Fe3Al powders via CGS onto steel substrates, evaluating the use of Helium (He) and Nitrogen (N2) as carrier gases, examining the influence of particle size distribution of two powders. The coatings have been optimized by studying the splat formation and their microstructures to better understand the deposition process. The best coatings have been characterized by microstructural analysis with scanning electron microscopy and energy dispersive X-ray spectroscopy, also measuring their microhardness. The work concludes that Fe3Al coatings have been successfully deposited by CGS. Therefore, dense coatings were achieved by using both He and N2 as carrier gases for the fine powder. Even so, the use of He as the carrier gas produces thicker and harder coatings, as particles reached higher velocities, allowing also to produce a good coating with the coarse powder.
Identifying the Atomic Layer Stacking of Mo2C MXene by Probe Molecule Adsorption
(American Chemical Society, 2021-12-09) Jurado, Anna; Morales García, Ángel; Viñes Solana, Francesc; Illas i Riera, Francesc
A density functional theory study is presented here aimed at investigating whether the atomic stacking on the new family of two-dimensional MXene materials has an influence on their adsorption properties and whether these properties can provide information about this structural feature. To this end, the Mo2C MXene, exhibiting two nearly degenerate crystal structures with either ABC or ABA atomic stacking, is chosen as a case study. The study of the adsorption of CO, CO2, and H2O on both polymorphs of Mo2C reveals substantial differences that could be used in experiments to provide information about the atomic stacking of a given sample. Particularly, we show that the asymmetric and symmetric stretching modes of the adsorbed CO2 and the CO stretching mode are clear features that allow one to identify the stacking of atomic layers of the Mo2C MXene. The present finding is likely to apply to other MXenes as well.
Finding Key Factors for Efficient Water and Methanol Activation at Metals, Oxides, MXenes, and Metal/Oxide Interfaces
(American Chemical Society, 2022-01-21) Su, Hai-Yan; Sun, Keju; Gu, Xiang-Kui; Wang, Sha Sha; Zhu, Jing; Li, Wei-Xue; Sun, Chenghua; Calle Vallejo, Federico
Activating water and methanol is crucial in numerous catalytic, electrocatalytic, and photocatalytic reactions. Despite extensive research, the optimal active sites for water/methanol activation are yet to be unequivocally elucidated. Here, we combine transition-state searches and electronic charge analyses on various structurally different materials to identify two features of favorable O–H bond cleavage in H2O, CH3OH, and hydroxyl: (1) low barriers appear when the charge of H moieties remains approximately constant during the dissociation process, as observed on metal oxides, MXenes, and metal/oxide interfaces. Such favorable kinetics is closely related to adsorbate/substrate hydrogen bonding and is enhanced by nearly linear O–H–O angles and short O–H distances. (2) Fast dissociation is observed when the rotation of O–H bonds is facile, which is favored by weak adsorbate binding and effective orbital overlap. Interestingly, we find that the two features are energetically proportional. Finally, we find conspicuous differences between H2O/CH3OH and OH activation, which hints toward the use of carefully engineered interfaces.
Insights of a Novel HEA Database Created from a Materials Perspective, Focusing on Wear and Corrosion Applications
(MDPI, 2025-07-23) Betancor, Lorena; Clave, Genís; Barreneche, Camila; Dosta Parras, Sergi
In recent years, interest in HEAs has increased exponentially due to their extraordinary properties, especially for wear- and corrosion-resistant applications. However, the main problem involves correctly selecting the HEA composition required for a specific application, as most of the data are scattered throughout the literature, and only a limited number of models accurately predict the properties. Therefore, a database of 415 HEA alloys (bulk) and coatings obtained using thermal spray (TS) techniques has been created, compiled from scientific studies over the past 20 years. This tool collects information on physical, mechanical, and chemical properties, with a particular emphasis on corrosion and wear resistance. This facilitates material comparison and selection according to the needs of a specific application. In particular, the database highlights how composition and deposition technique also affect performance, identifying CoCrFeNi (CGS and in bulk) as a promising candidate for simultaneous wear and corrosion resistance.
In-depth study of the dry-anodizing process on Ti6Al4V alloys: Effect of the acid content and electrical parameters
(Elsevier B.V., 2025-01-10) Valencia Cadena, Andrea; García Blanco, M. Belen; Reschenhofer, Bernhard; Barreneche, Camila; Skerbis, P.; Leitl, P.A.; Santamaría Cabodevilla, Pablo; Roa Rovira, Joan Josep
Titanium (Ti) surface has the capability of changing color due to the oxides formed when it meets oxygen under acidic solutions and current application. Additionally, this passive oxide film formed on the Ti surface is responsible for its high corrosion resistance that is needed in several industries. Consequently, titanium has a wide range of applications in the aerospace, automotive, and biomedical industries. This study introduces a never-used dry-anodizing process utilizing DryLyte® Technology. In this sense, the effects of electrical parameters (voltage, and current density) and the acid content of the dry electrolyte on the performance of the new dry-anodizing process are evaluated using different advanced characterization techniques. Direct and indirect coating thickness measurement of the anodic layer by using the Focused Ion Beam and reflectometric techniques, respectively, revealed that the anodic layer thickness does not depend on the acid content, yielding a homogeneous value of around 60 nm. Additionally, the study demonstrated that the application of low-frequency pulses with a duty cycle of 20 %, reduce the heating during the process and allows to increase further the anodizing voltage compared with direct current anodizing, thereby expanding the available color range. Finally, the experimental results were adjusted to a polynomial fitting to predict the TiO2 anodizing layer thickness induced along the process. From all the aforementioned information, it has been stablished that the anodizing quality of the dry electrolyte decreases under service-like working conditions, which is mainly attributed to two different effects related to the electrical current that passes through the polymeric particles and that takes place at the same time: (1) dehydration of the particle and (2) degradation of the core-shell structure, caused by Joule's effect during the dry-anodizing process.
Hybridization of Salt Hydrates with Solid–Solid Phase Change Materials: A Novel Pathway to Sorption Thermochemical Materials Manufacturing
(Wiley-VCH, 2023-05-13) Palacios, A.; Navarro, M.E.; Barreneche, Camila; Ding, Y.
Major advancements are needed in the thermochemical energy storage (TCES) field to bring the technology to commercial levels. The current research strategies are focused on improving heat and mass transfer using different supporting materials to achieve mechanical integrity during storage. However, these strategies are still under development, and they have not overcome the lab scale yet. This work explores novel matrices to expand the material database for TCES composites. Pure structural matrices (cellulose) and novel matrices with storage potential (polymeric solid–solid phase change materials) are selected and combined with three well-known thermochemical materials (TCMs) (MgSO4·6H2O, SrBr2·6H2O and MgCl2·6H2O), providing evidence of hybridized composites with storage capacity up to 2.4 GJ m−3 with a 25–20 wt% of polymeric matrix. The polymer content is found to act as a nucleating agent in the magnesium sulfate crystallization process forming a synthetic monohydrate crystalline phase (Kieserite) and inhibiting the formation of the amorphous phase. The effect of the matrix is proved to induce certain structural deformation or changes not observed in the pure TCM sorption process. This phenomenon has the potential to benefit the stabilization of the TCM, e.g., inhibition of the formation of amorphous phase in magnesium sulfate composites.
Performance analysis of a novel multi-module columnar packed bed reactor with salt hydrates for thermochemical heat storage
(Elsevier, 2024-05-01) Hao, C.; Feng, G.; Ma, C.; Barreneche, Camila; She, X.
The thermochemical heat storage based on salt hydrate has great advantages of high energy storage density and applicability to seasonal heat storage. In conventional packed-bed reactors, salt hydrates are often simply accumulated, and the air diffuses inside the pores. As a result, the salt hydrates are prone to agglomeration during the reaction, which will reduce the performance. To address these issues, this paper designs a multi-module columnar packed-bed reactor. The performance of top peripheral air intake and bottom central air intake schemes is numerically compared, and the effects of working parameters, structural parameters and physical parameters are analyzed. The results show that the bottom central air intake scheme has obvious advantages of uniform reaction rate, short reaction time and small resistance loss compared with the top peripheral air intake scheme. It is found that the reaction time is shortened by 46.6 % and the heat storage efficiency increases from 80.4 % to 83.8 % when the inlet air temperature increases from 75 to 95 °C. Besides, the reaction time decreases by 20.7 % as the inlet air velocity increased from 1 to 3 m/s and the optimal spacing of the hydrated salt modules is 0.3 cm. These results are promoting the development of thermochemical heat storage.
Protective Laser Cladding Coatings for Thermal Energy Storage Tanks in contact with Molten Salt-Based Nanofluids
(Elsevier, 2026-04-06) Betancor, Lorena; Svobodova Sedlackova, Adela; Clave, Genís; Barreneche, Camila; Dosta Parras, Sergi
Intermittency of renewable energy sources is a critical problem. Concentrated Solar Power (CSP) power plants with thermal storage systems offer one of the main solutions. Among the many storage processes, nanofluids are a method of improving thermal performance but inducing corrosion of storage units. This study investigates the potential of Inconel-625 and Stellite-6 coatings deposited by laser cladding in preventing nanofluid-induced corrosion in CSP thermal storage units. AISI 316L stainless steel samples coated with Stellite-6 and Inconel-625 were tested for corrosion in NaNO3 containing SiO2 nanoparticles at 450 °C for 30, 60, and 90 days. Cross-section analysis was used to assess thickness loss, and coatings were analysed. Chemical attack enhanced material contrast for microstructural observation. Compositions of oxides were identified by EDS and XRD analysis, and ICP analysis identified elements in the salts after corrosion. Results showed almost no loss in thickness, even after 90 days, to substantiate the protective efficacy of coatings. Results confirm that Inconel-625 and Stellite-6 coatings are a reliable source of preventing corrosion caused by nanofluids in CSP thermal storage systems.
Experimental evaluation of carbon-coated sand as solar-absorbing and thermal energy storage media for concentrated solar power applications
(Elsevier, 2025-06-15) Rodríguez, J.B.; Majó, M.; Mondragón, Rosa; Barreneche, Camila; Díaz-Heras, M.; Canales-Vázquez, J.; Almendros-Ibáñez, J.A.; López Hernández, Leonor
Innovative systems using solid particles for solar energy capture, heat transfer, and thermal energy storage are emerging in next-generation concentrating solar power plants. This study investigates silica sand enhancement using novel coatings of graphite, carbon black, and glucose, evaluating their thermal stability, optical properties and durability under operational conditions. The coated samples were subjected to fluidisation and radiation treatments to simulate real-world conditions. Thermogravimetric analysis, specific heat capacity measurements, optical absorptance evaluation, and photothermal conversion efficiency testing were performed. The results show that graphite-coated sand exhibits superior optical and thermal performance, achieving a 44.9 % increase in photothermal conversion efficiency compared to uncoated sand. While carbon black coatings displayed higher absorptance, their heterogeneity compromised long-term effectiveness. Glucose coatings degraded above 280 °C, rendering them unsuitable. An industrial-scale fluidised bed model was used to assess the impact of the observed enhanced particle absorptance on the resulting performance of these systems, revealing thermal efficiency improvements of 50 %. These findings confirm that graphite-coated sand is a viable solution for high-temperature concentrating solar power plants applications, offering stable performance, enhanced light-to-heat conversion and improved energy efficiency in large-scale

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