Artículos (Ingeniería y Ciencia de los Materiales y del Transporte)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/11377

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Development of hybrid nanoparticles based on Zr(iv) and perylene-3,4,9,10-tetracarboxylic acid with visible-light photoredox activity
(Royal Society of Chemistry, 2026-02-02) Cacciari, R. Daniel; Gonik, Eduardo; Beltrán, Ana M.; Mizrahi, Martin D.; Ezquerra Riega, Sergio D.; Rodríguez, Hernán B.; González, Mónica D.; Ingeniería y Ciencia de los Materiales y del Transporte; TEP123: Metalurgia e Ingeniería de los Materiales
Herein, we investigate perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) as a linker in Zr-clusters. The photostable, 3D metal–organic nanomaterial obtained by a solvothermal synthesis procedure in the presence of formic acid as modulator, named ZIPER, shows strong absorption in the visible (400–560nm) and an intense photoluminescence (PL) in the 600–700 nm range. PL quenching experiments strongly indicate that the ZIPER excited state (ZIPER*) behaves primarily as a strong oxidant and a mild reductant with redox couples E(ZIPER*/ZIPERc −) = 1.8–1.2 V and E(ZIPERc+/ZIPER*) = −0.44–−0.48 V (vs. NHE). Amine quenching of ZIPER* PL led to a strong reductant (ZIPER −) with E(ZIPER/ZIPERc −) <−0.6 V vs. NHE. This reactivity was exploited to drive the reductive dehalogenation of model polychlorinated compounds, such as carbon tetrachloride and trichloroacetic acid, through visible-light photoredox catalysis in aqueous suspension. In contrast, under air-saturated conditions, the system predominantly produces substantial amounts of H₂O₂. A detailed analysis of the results suggests that photoexcitation of the organic linkers is followed by electron transfer to the Zr cluster. Charge-separated states are mainly stabilized in the presence of suitable electron donors or acceptors; otherwise, the system relaxes radiatively, emitting strong orange fluorescence.
Feasibility of a new GRT setup for the analysis of quaternary metal alloys with radioactive gamma sources
(Elsevier, 2025-11) Moreno-Soto, Javier; Ager Vázquez, Francisco José; Paúl Escolano, Antonio; Gómez Tubío, Blanca; Ortega-Feliú, Inés; Ferreti, Marco; Respaldiza Galisteo, Miguel Ángel; Física Aplicada I; Ingeniería y Ciencia de los Materiales y del Transporte; Física Aplicada III; Física Atómica, Molecular y Nuclear; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; European Union (UE); RNM138: Física Nuclear Aplicada; TEP973: Tecnología de Polvos y Corrosión
Analysing archaeological artefacts made from metallic alloys is often challenging due to the impracticality of sample collection. Traditional non-invasive surface techniques, such as X-ray fluorescence (XRF), electron probe microanalysis (EPMA), scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), and particle-induced X-ray emission (PIXE), among others, may yield misleading results if the objects are affected by corrosion or enrichment effects. Consequently, these techniques need to be complemented with others to gain a precise understanding of alloy composition. Gamma-ray transmission (GRT) is a non-destructive technique that can reveal the bulk composition of a sample. A new GRT setup has been developed to measure the concentrations of binary, ternary, and quaternary alloys using three sources simultaneously, reducing the measurement time. Alloys made in the laboratory were analysed with XRF, showing notable composition discrepancies in some cases, while the GRT results agreed with the expected composition. This innovative GRT setup, with its potential to significantly contribute to future archaeological investigations of alloy compositions, proves to be a valuable tool for analysing metallic artefacts.
Transglutaminase as an Enzymatic Crosslinker of Protein-Based Thermoformed Bioplastics
(Springer, 2025-11) Granados Carrera, Carmen M.; Humanes-Partida, María; Capezza, Antonio J.; Romero García, Alberto; Pérez-Puyana, Víctor Manuel; Ingeniería Química; Ingeniería y Ciencia de los Materiales y del Transporte; Ministerio de Hacienda y Función Pública
The packaging industry needs to develop new materials to replace conventional plastics. This is where bioplastics, primarily derived from biopolymers such as proteins, come into play in addressing this problem. However, given their overall mechanical properties, cross-linking methods are needed to improve their performance compared to synthetic counterparts. Thus, this article proposes the development of bioplastics using pea protein as a biopolymer and glycerol as a plasticizer in different ratios (60/40 and 70/30), and incorporating transglutaminase as a natural cross-linking agent (0.25% and 0.50% concentrations), using compression molding as a processing technique for the development of prototypes. Therefore, the mechanical, thermal, optical, physicochemical, and functional properties were analyzed, demonstrating, first of all, the obtention of a material with a glass transition temperature of approximately 65–70 °C lower than that of conventional plastics such as PET. In this way, the materials showed an improvement in flexural properties (obtaining an elastic modulus of 1–2 MPa), at the expense of a deterioration in tensile tests (with a Young’s Modulus of 20–30 and 45–50 MPa for the 60/40 and 70/30 formulations, respectively). Similarly, opacity was increased by incorporating the enzyme into the formulation, highlighting its role in the 70/30 formulation with 0.50% of the enzyme. Moreover, this enzyme also reduced the water absorption capacity by approximately 13%. This demonstrates the potential application of this type of material in dry product packaging, which maintains its properties after a period of 125 min with a moisture content of 3–5%, highlighting its viability for the development of more environmentally responsible packaging solutions.
Eight-Year Cohort Study Examining Bicycling-Related Maxillofacial Fractures and Factors Contributing to Injury
(Multidisciplinary Digital Publishing Institute (MDPI), 2025-11) González Pérez, Luis Miguel; Wideberg, Johan; Álvarez Delgado, Carlos; Ingeniería y Ciencia de los Materiales y del Transporte; Cirugía
Objectives: The aim of this study was to determine the epidemiological characteristics of bicycling-related maxillofacial fractures in a defined population and to identify factors contributing to these injuries. Methods: An 8-year cohort study was carried out, including all patients presenting with bicycling-related maxillofacial fractures at a tertiary care center from 2017 through 2024. Data recorded for each patient included age, gender, date and cause of injury, contributing factors, type of facial fractures, other injuries, hospital stay, and helmet use. Statistical analysis was performed. Continuous variables were assessed for normality (Shapiro–Wilk test) and compared using the Mann–Whitney test. Categorical variables were analyzed with chi-square tests. A p-value ≤ 0.05 was considered statistically significant. Results: Out of 899 cycling accident patients seeking medical treatment, 122 (13%) sustained facial fractures, accounting for 4% of all facial fracture cases in our department during the study period. In our cohort, the male–female ratio was 2.6:1, and the mean age was 29.5 years (SD 12.8, range 13–77). Collision with another object/vehicle was the most common cause (64%), followed by isolated falls (36%). A total of 135 facial fractures were recorded (some patients had multiple fractures). Mandibular fractures were most frequent (49% of patients), followed by zygomatic (32%), orbital (13%), nasal (7%), maxillary (2%) and frontal (2%) fractures. Among mandibular injuries, condylar fractures were the most common subtype (63%). Dental injuries were found in 27% of patients. The most common dental trauma was tooth fracture (43% of those with dental injuries), followed by tooth luxation (32%) and tooth avulsion (25%). In 80% of cases involving dental injuries, the upper anterior teeth were involved. Concomitant injuries were present in 20% of patients, most often orthopedic limb injuries. Only 27% of patients reported always wearing a helmet, whereas 43% reported never having worn one. Conclusions: Bicycling-related facial injuries are a noteworthy subset of facial trauma. Missed or delayed diagnosis can lead to lasting deformities and functional issues. Preventive strategies—especially promoting helmet use and improving helmet design—along with broader safety measures are important to reduce the incidence and severity of these injuries.
Evaluation of corrosion resistance of steel alloys in ternary molten salt: implications for TES and industrial heat applications
(Elsevier, 2026) Pavón Moreno, María del Carmen; López-Paneque, Antonio Manuel; Paúl Escolano, Antonio ; Gallardo Fuentes, José María; Prieto Ríos, Cristina; Ingeniería Energética; Ingeniería y Ciencia de los Materiales y del Transporte; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; European Union (UE)
Several steel alloys were evaluated for their corrosion resistance in ternary molten salt (NaNO3–KNO3–NaNO2, 53-40-7 wt%) at 400 °C under an air atmosphere, with a focus on thermal energy storage (TES) and industrial heat applications. Alloys A335-P11, SS321, A213-T11, A516-Gr70, and A387-Gr11 were tested using static immersion in accordance with ASTM G31 over exposure periods of 1000, 2000, and 4000 h. Corrosion rates derived from mass loss measurements revealed significant differences among the alloys. SS321 demonstrated the best resistance, with stable chromium-rich oxide scales and rates consistently below 4 μm/year. In contrast, A335-P11 exhibited the highest corrosion rate, with an initial rate of 65 μm/year that decreased to 18 μm/year over time, associated with thick, cracked oxide scales and localized internal attack. The remaining alloys showed intermediate corrosion behavior. SEM/EDS analyses confirmed the critical role of chromium enrichment in improving corrosion resistance. In parallel, mechanical integrity assessments showed no evidence of stress corrosion cracking or severe crevice corrosion, underscoring the predominance of generalized oxidation as the governing degradation mode. These results provide critical insights for predictive corrosion modeling and support the selection of durable materials for reliable, long-term operation in molten salt-based industrial thermal systems, thereby contributing to the transition toward more sustainable high-temperature heat applications.
Impurity-induced formation of Ti₁₋ₓZrₓB₂ solid solution ceramics during combined SHS-SPS sintering
(Elsevier, 2026) López Arenal, Jesús; Moshtaghion, Bibi Malmal; Gómez García, Diego; García Fernández, María ; Rodríguez, Miguel A.; Moreno, Rodrigo; Ingeniería y Ciencia de los Materiales y del Transporte; Física de la Materia Condensada; Ministerio de Ciencia e Innovación (MICIN). España
Combination of self-propagating high-temperature synthesis (SHS) from Ti + B powder mixture followed by spark plasma sintering (SPS) is introduced for the fabrication of titanium diboride. Oxide impurities, including zirconium oxide and titanium oxide, are identified in the synthesized powders: the first one coming from the milling process after SHS to minimize agglomeration and the second one is a common oxide fine layer on particle surface. Both oxide phases are reduced during SPS treatment. Results confirm that increasing the SPS temperature enhances the reduction of ZrO₂, facilitating the incorporation of Zr cations into the lattice through substitution at Ti sites, thus allowing the formation of this solid solution diboride: Ti1-xZrxB2. The key finding is that the presence of a small amount of Zr cation, with higher atomic radius in TiB2 crystal structure results in crystal distortion and it creates significant solid solution hardening effect as well as an improved wear response.
Bioinspired nacre-like hierarchical chitosan/hydroxyapatite coatings by electrophoretic deposition
(Elsevier, 2026-02) Baştan, Fatih E.; Akhtar, M. Asim; Krapf, Anna; Roether, Judith A.; Beltrán, Ana M.; Göken, Mathias; Boccaccini, Aldo R.; Ingeniería y Ciencia de los Materiales y del Transporte; TEP123: Metalurgia e Ingeniería de los Materiales
Nacre's unique microstructural arrangement, hierarchical alternating stackings of organic molecules and inorganic platelets, yields superb mechanical efficiency beyond the predictions of the rule of mixture. In this study, we produced ordered chitosan (CS)/hydroxyapatite (HA) coatings by electrophoretic deposition (EPD), mimicking the nacre's hierarchical brick-and-mortar microstructure. To build such a hierarchic structure, we used platelet-shaped HA particles oriented in the (100) plane, which obviated the common need for 2d templates for creating nacre-mimetics. The coatings showed an ordered and layered structure of the HA plates (64–86 wt.%) mediated by CS molecules, resulting in a superior elastic modulus (12 GPa) and relatively high wear resistance. The coatings were also a perfect platform for rapid apatite formation and pre-osteoblast cell proliferation. After 7 days, the cell population on the coatings was nearly doubled relative to that on plain stainless steel. The collective benefit of outstanding mechanical performance and superior in vitro performance of the CS/HA coating was conferred by the nacre mimetic design. This study can pave the way for expanding the use of the nacre motif in electrophoretically deposited biomedical coatings.
On the optimisation of the composition of high-entropy alloys
(Springer, 2025) Montes Martos, Juan Manuel; Ternero Fernández, Fátima; Ingeniería y Ciencia de los Materiales y del Transporte; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; TEP971: Ingeniería de Materiales Avanzados
The aim of this work is to find a simple and fast way to fix the composition of a multi-component alloy that maximises the probability that it will have a solid-solution single-phase microstructure. The search begins with a detailed analysis of the well-known parameter Ω, which has already been the subject of studies aimed at maximising it. In line with these theoretical efforts, this paper proposes: (i) a new optimisation strategy, in accordance with the classical definition of a multi-principal-components alloy, (ii) improvements in the calculation of the Ω parameter (through the enthalpy of mixing) and (iii) the definition of a new indicator, which we will call the Λ parameter, which also can be optimised. This new parameter not only takes into account the enthalpy of mixing, but also adds an additional term, the elastic lattice distortion enthalpy, caused by the distortion of the crystal lattice. Both the new maximisation strategy and the new parameter aim to ensure that the high precision of the composition at the maximum does not make it impossible to implement. As a novelty, this paper uses the Excel spreadsheet and its Solver tool for the task of maximisation with constraints, using the evolutionary algorithm. The paper applies the optimisation methods discussed to two multi-component systems that have been widely analysed in the specialised scientific literature, in order to compare all the techniques described. Finally, the article points to the possibility that optimisation of the indicator parameters Ω and Λ could provide the two most stable compositions into which an initially single-phase alloy subjected to high temperature would segregate.
The Impact of Steel Fiber Length and Dosage on Microstructure and Mechanical Performance in UHPFRC: A Hybrid Approach
(Asociación Española de Ingeniería Estructural (ACHE), 2025) Ruiz Martínez, Jaime D.; Ríos Jiménez, José David; Pérez-Soriano, Eva María; Cifuentes-Bulté, Héctor; Leiva Fernández, Carlos; Ingeniería Química y Ambiental; Mecánica de Medios Continuos y Teoría de Estructuras; Ingeniería y Ciencia de los Materiales y del Transporte; Ministerio de Ciencia e Innovación (MICIN). España
This study evaluates the effects of steel fiber length (6 and 13 mm) and dosage on the microstructural and mechanical properties of an ultra-high-performance fiber-reinforced concrete (UHPFRC). The incorporation of 6 mm fiber significantly improved the material's workability characteristics. Microscopic evidence indicates better alignment and distribution of 13 mm fibers within the concrete matrix compared to 6 mm fibers, resulting in reduced porosity and enhanced matrix-fiber interaction. Mechanical testing confirmed that the inclu-sion of 13 mm steel fibers at various dosages consistently outperformed 6 mm fibers in enhancing compressive and flexural strengths. The optimal dosage, among those tested, for compressive strength was found to be 196 kg/m³ with 13 mm fibers, while the best performance in flexural strength was observed at 226 kg/m³. To address the challenges inherent in UHPFRC—specifically the intricate metallic fiber distri-bution and limited workability prompted a comprehensive investigation into fiber mixture optimization strategies. Hybrid fiber approach was explored by substituting 10%, 20%, and 30% of the 13 mm fiber dosage (196 kg/m³) with 6 mm steel fibers. Among these, the mix containing 80% of 13 mm steel fibers and 20% of 6 mm steel fibers demonstrated the highest flexural strength, even than those with higher steel fiber content (226 kg/m3). This hybridization suggests an optimized combination of fiber lengths for enhanced flexural performance without compromising compressive strength, providing insights into effective fiber-reinforcement strategies for UHPFRC applications.
Infiltrated 3D-printed zirconia scaffolds with biodegradable and bioactive polymer blend to improve their osseointegration
(Elsevier, 2025-12) Delgado-Pujol, Ernesto J.; Razavi, Ali; Begines Ruiz, Belén; Llanes, Luis; Morales, Miguel; Alcudia Cruz, Ana; Torres Hernández, Yadir; Fargas, Gemma; Ingeniería y Ciencia de los Materiales y del Transporte; Química Orgánica y Farmacéutica; Ministerio de Ciencia e Innovación (MICIN). España; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; TEP123: Metalurgia e Ingeniería de los Materiales; FQM408: Química Farmacéutica Aplicada
Bone defects and skeletal disorders continue to demand advanced biomaterials that combine mechanical strength with enhanced bioactivity and customizability. While yttria-stabilized zirconia (YSZ) offers excellent mechanical properties and biocompatibility, its bioinert nature and processing challenges limit its effectiveness for patient-specific bone implants. This study addresses this gap by developing novel polymer-infiltrated ceramic network (PICN) scaffolds based on 3D-printed porous YSZ fabricated via Direct Ink Writing (DIW). The scaffolds were infiltrated with biodegradable polycaprolactone (PCL)/polyvinyl alcohol (PVA) blends loaded with nanohydroxyapatite (nHA) to impart bioactivity and tunable degradation. Scaffold designs with 40 % and 60 % infill were evaluated for infiltration efficiency, mechanical performance, degradation behavior, and apatite formation capacity. Results demonstrated high infiltration rates (up to 96 %, particularly in 40 % infill scaffolds), mechanical integrity comparable to cancellous bone (compressive strength within the range of 2–12 MPa), and enhanced in vitro apatite formation, especially for scaffolds with an 80:20 PCL/PVA blend containing 15 % nHA. The degradation analysis indicated that higher PVA content accelerated resorption, with the 50:50 blend showing faster surface changes, while the 80:20 blend maintained gradual porosity increase aligned with tissue replacement. Overall, this work presents a feasible strategy for fabricating patient-specific ceramic scaffolds with enhanced osseointegration potential, thereby bridging the gap between mechanical stability and biological functionality for future bone and dental implant applications.
Material design of novel TiNbTaHfMo high-entropy alloys for biomedical implants: Exploring an industry-adaptable route via FAST/SPS
(Elsevier, 2025-10) Chávez-Vascónez, Ricardo; Arévalo Mora, Cristina María; Sauceda, Sergio; Leiva, Jeremi; Oñate, Angelo; Pérez-Soriano, Eva María; Lozano Suárez, Juan Gabriel; Torres Hernández, Yadir; Lascano, Sheila; Ingeniería y Ciencia de los Materiales y del Transporte; Universidad de Sevilla; TEP123: Metalurgia e Ingeniería de los Materiales
Novel non-equiatomic Ti–Nb–Ta-Hf-Mo alloys were designed using β-Ti and high-entropy alloy formulation strategies to develop low-modulus materials for load-bearing biomedical implants. Ti₄₀₋ₓNb₂₅Ta₂₅Hf₁₀Moₓ (x = 0, 5, 10 at.%) alloys were designed by combining the d-electron method for β-Ti alloys with conventional HEA design parameters, aiming to develop low-modulus materials for load-bearing biomedical implants. Compositions were optimized through CALPHAD thermodynamic modeling and validated using a random forest machine learning approach, with predictions matching phase transformations detected during sintering. Alloys were fabricated via elemental powder blending and spark plasma sintering (FAST/SPS) under varied temperatures and dwell times, achieving densification from ∼90 % at 1250 °C/5 min to 98 % at 1350 °C or 10 min. Higher Mo content promoted and stabilized body-centered cubic (BCC) structures even at lower temperatures or shorter times. Mechanical testing confirmed Young's moduli of 16–74 GPa, tunable through densification control to balance strength and mitigate stress shielding. Despite a heterogeneous microstructure, the mechanical performance was comparable to alloys produced by longer, costlier routes. This work demonstrates FAST/SPS from elemental powders as a rapid, scalable, and industrially attractive method for producing biomedical HEAs.
Collagen/rGO/tannin hydrogels with a programmable biointerface for tunable electrical conductivity and antioxidant capacity in tissue regeneration
(Elsevier, 2025-09-30) González, Luisbel; Ruiz, Isleidy; Raposo, María; Aguayo, Claudio; Toledo, Jorge R.; Pérez-Puyana, Víctor Manuel; Romero García, Alberto; Fernández, Katherina; Ingeniería Química; Ingeniería y Ciencia de los Materiales y del Transporte; Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT). Chile; Ministerio de Ciencia e Innovación (MICIN). España
Restoring the endogenous bioelectric field while simultaneously protecting healing tissue from mechanical and oxidative stress remains a major challenge for next-generation wound dressings. Here we present an interface-programmed collagen hydrogel that integrates dopamine-reduced graphene oxide (rGO-PDA), polyethylene glycol (PEG) and condensed tannins (TA) into a single supramolecular network. rGO-PDA provides electronic pathways; TA forges multivalent π–π and hydrogen-bond bridges that immobilize rGO within the fibrillar matrix, confer radical-scavenging capacity and compatibilized the organic/inorganic phases; PEG acts as a hydrophilic spacer that tunes porosity and plasticity. Compared with the PEG-plasticized collagen control, the optimized COL/PEG20/TA10 formulation increased the storage modulus fourfold to 47 kPa, doubled the critical strain, raised the thermal decomposition onset by 80 °C and achieved stable conductivities of 10.3 mS/cm, comparable to native skin. The same interfacial design lowered the water-contact angle to 33 °, raised swelling to 150 % and enabled a biphasic release of TA that maintained 30 % DPPH inhibition for 4 h. Extracts enhanced human dermal fibroblast viability to 151 ± 5 % and accelerated in vitro scratch closure to > 95 % in 48 h. In a porcine full-thickness model the hydrogel achieved complete, scar-free re-epithelialization and highly organized dermal architecture within 21 days, while rabbit and guinea-pig tests confirmed it to be non-irritant. These results demonstrate that molecularly engineered collagen/rGO/TA interfaces can synchronously deliver mechanical reinforcement, bioelectronic stimulation and antioxidant defense, providing a scalable, all-natural platform for advanced wound management.
Size tuneability of highly efficient li-rich cathode materials using an emulsion-based synthesis route
(Elsevier, 2026-02) Rubio, Saúl; Beltrán, Ana M.; Arévalo Mora, Cristina María; Martínez, Gerardo T.; García-García, Francisco J.; Pérez-Soriano, Eva María; Montealegre-Meléndez, Isabel; Lozano Suárez, Juan Gabriel; Ingeniería y Ciencia de los Materiales y del Transporte; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); TEP123: Metalurgia e Ingeniería de los Materiales
Lithium- and manganese-rich transition metal oxides exhibit excellent specific capacities, making them strong candidates for the development of the next generation of Co-free lithium-ion batteries. In this study, the synthesis of size-tunable Li₁ꓸ₂Ni₀ꓸ₂Mn₀ꓸ₆O₂ using a synthetic route based on the formation of an emulsion, which is ultra-fast, cost-effective, and easily scalable to an industrial level is presented. We demonstrate that variations in the concentrations of hydrophobic, hydrophilic, and surfactant components, which lead to micelle formation within the emulsion, have a significant impact on the average particle size and size distribution of the synthesized material, and subsequently, on their electrochemical performance. Specifically, increasing the concentration of oleic acid as a surfactant results in an optimal average particle size, with discharge specific capacities exceeding 317 mAh g⁻¹ in the first cycle and 230 mAh g⁻¹ after 100 cycles, demonstrating an excellent battery performance comprising state-of-the-art lithium- and manganese-rich transition metal oxide materials.
Nanoscale imaging and atomic vibrations of eumelanin superstructures modulated by functionalized micronized graphene oxide
(Royal Society of Chemistry, 2025-09-17) Matassa, Roberto; Mattiello, Sara; Soares, Gustavo Guerreiro Candido; Lozano Suárez, Juan Gabriel; Beltrán, Ana M.; Zazza, Costantino; Sanna, Nico; Phua, Jun Wei; Rosolen, Jose Mauricio; Cicco, Andrea di; Rezvani, Javad; Gunnella, Roberto; Ingeniería y Ciencia de los Materiales y del Transporte; TEP123: Metalurgia e Ingeniería de los Materiales
Natural organic/inorganic materials with rational cooperative formations have long been of enormous interest owing to their hybrid self-assembling properties. Natural biomolecules are expected to produce attractive superstructures capable of sensing their environment, following their inherent biological functions and high biocompatibility. However, understanding their assembly strategies with inorganic materials is often challenging. Herein, we investigated the bioactive assembly of natural eumelanin superstructures. modulated by chemical functionalization of micronized graphene oxide, to study their strong structural affinity by analysing their vibrational–structural correlations. The application of complementary experiments of high-resolution electron nanoimaging coupled with vibrational Raman spectroscopy revealed intriguing and unique features of this complex hybrid material. In particular, high-resolution nanodiffraction/imaging analysis provided evidence of new nanocrystalline domains of pure natural eumelanin with different and irregular orientations forming irregular nanosheets. Interestingly, a hierarchical reassembly process of eumelanin units are actually evident not only on the oxide graphene surface but also located in high amounts on the edge of vertical graphene oxide, concretely supported by the analytical changes of the predominant resonance bands (D, D**, and G). This confirmed the ability of eumelanin to reassemble in spherical and elongated nanostructures when induced by an external stimuli of graphene oxide in an aqueous solution at room temperature. Thus, this work highlights the assembling mechanisms for designing a strategy to control bioactive molecules through environment modification.
Comparative Assessment of Injection and Compression Molding on Soy Protein Bioplastic Matrices for Controlled Iron Release in Horticulture
(Multidisciplinary Digital Publishing Institute (MDPI), 2025-06-17) Castro Criado, Daniel; Jiménez Rosado, Mercedes; Pérez-Puyana, Víctor Manuel; Romero García, Alberto; Ingeniería Química; Ingeniería y Ciencia de los Materiales y del Transporte; Ministerio de Ciencia e Innovación (MICIN). España; Junta de Andalucía
Conventional horticultural fertilization frequently leads to nutrient loss and environmental contamination, driving interest in biodegradable controlled-release systems. This work developed soy protein isolate (SPI) matrices containing 5 wt.% FeSO4·7H2O using injection. The matrices were evaluated for crosslinking, mechanical properties, water uptake (WUC), soluble matter loss (SML), iron-release kinetics in water and soil, and biodegradability under composting conditions. Injection-molded samples achieved very high crosslinking with moderate rigidity and water absorption and delivered iron rapidly in water, while compression-molded samples exhibited slightly lower crosslinking but greater stiffness, higher WUC, minimal SML, and sustained iron release. Notably, both processing methods yielded comparable iron-release profiles in soil and complete biodegradation within 71 days. Overall, compression molding produces SPI-based matrices with superior mechanical strength and water retention, positioning them as an ideal solution for long-lasting, sustainable nutrient delivery in horticulture.
The Influence of Electrostatic Separation Parameters on the Recovery of Metals from Pre-Crushed PCBs
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) López-Paneque, Antonio Manuel; Gallardo García-Orta, Victoria Humildad; Gallardo Fuentes, José María; Sepúlveda Ferrer, Ranier Enrique; Chicardi Augusto, Ernesto; Ingeniería Energética; Ingeniería y Ciencia de los Materiales y del Transporte; European Institute of Innovation and Technology (EIT)
Electrostatic separation is a promising technology for the recovery of valuable metals from electronic waste, particularly from printed circuit boards (PCBs). This study explores the application of electrostatic separation for the selective recovery of metallic and non-metallic fractions from crushed PCBs (PCBs). The process exploits the differences in electrical properties between conductive metals and non-conductive polymers and ceramics, facilitating their separation through applied electric fields. The raw materials were pre-treated via mechanical comminution using shredders and hammer mills to achieve an optimal particle size distribution (<3 mm), which enhances separation efficiency. Ferrous materials were removed prior to electrostatic separation to improve process selectivity. Key operational parameters, including particle size, charge accumulation, environmental conditions, and separation efficiency, were systematically analysed. The results demonstrate that electrostatic separation effectively recovers high-value metals such as copper and gold while minimizing material losses. Additionally, the process contributes to the sustainability of e-waste recycling by enabling the recovery of non-metallic fractions for potential secondary applications. This work underscores the significance of electrostatic separation as a viable technique for e-waste management and highlights optimization strategies for enhancing its performance in large-scale recycling operations.
Cobalt and Iron Double Doped B-Site Perovskite La0.5Ca0.5CoXFe1−XO3: Synthesis Strategy to Make High-Performance Oxygen Evolution Reaction Catalysts
(Wiley, 2025) Prakash P A, Jithin; Jose E, Tomlal; Thomas, Jasmine; Thomas, Tony; Chicardi Augusto, Ernesto; Periyasami, Govindasami; Jeffery, A. Anto; Thomas, Nygil; Ingeniería y Ciencia de los Materiales y del Transporte; King Saud University. Saudi Arabia
We developed a sustainable solution combustion method to synthesize the perovskite compounds of La0.5Ca0.5CoxFe1−xO3 (x = 0, 0.2, 0.4, 0.6, 0.8, 1) to enhance its electrocatalytic activity in oxygen evolution reactions by varying the ratios of iron (Fe) and cobalt (Co) at the B sites. The incorporation of Fe3+ and Co3+ in varying proportions at the B site is confirmed by PXRD, FTIR, FESEM, HRTEM, and XPS analyses. The synthesized polycrystalline spherical porous material, La0.5Ca0.5CoxFe1−xO3, exhibits thermal stability up to 1000 °C. Electrochemical investigations utilizing cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and Tafel plots have identified La0.5Ca0.5Co0.4Fe0.6O3 as the most effective electrocatalyst among a series of synthesized perovskites. This material exhibits a Tafel slope of 70.32 mV/dec and an overpotential of 364 mV at a current density of 10 mA/cm2. The enhanced OER activity stems from several factors, including a larger electrochemically active surface area, lower charge transfer resistance, a porous structure, and varying proportions of B-site ions.
Insights into Preformed Human Serum Albumin Corona on Iron Oxide Nanoparticles: Structure, Effect of Particle Size, Impact on MRI Efficiency, and Metabolization
(ACS Publications, 2019-06) Moya, Carlos; Escudero, Remei; Malaspina, David C.; Mata, María de la; Hernández-Saz, Jesús; Faraudo, Jordi; Roig, Anna; Ingeniería y Ciencia de los Materiales y del Transporte; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; TEP973: Tecnología de Polvos y Corrosión
In the past decade, profuse research efforts explored the uses of iron oxide particles in nanomedicine. To a great extent, the efficiency and fate of those magnetic nanoparticles depend on how their surfaces interface with the proteins in a physiological environment. It is well reported how an ungoverned protein corona can be detrimental to cellular uptake and targeting efficiency and how it can modify the nanoparticles biodistribution. Novel strategies are emerging to achieve enhanced and more reproducible performances of engineered nanoparticles with a custom-built protein corona. Here we report on a generalized protocol to preform a monolayer of human serum albumin (HSA) on superparamagnetic iron oxide nanoparticles (SPIONs) of different sizes. The resulting molecular structures are described by molecular dynamics simulations of the hybrid nanoconjugates. The simulations outcomes regarding the number of proteins in the corona and their monolayer arrangement on the particle surface are in agreement with the results obtained from dynamic light scattering and electronic microscopy analysis. Using tryptophan fluorescence quenching, we revealed the existence of a strong interaction between the SPIONs and the HSA which endorses the robustness of the protein−nanoparticle conjugates in this system. Moreover, we evaluated the effect of the HSA corona on the SPIONs efficiency as magnetic resonance imaging (MRI) contrast agents in water, human serum, and saline media. The protein corona did not affect the efficiency of the SPIONs as T2 contrast agents but reduce their T1 efficiency. In addition, we observed a greater stability for HSA-SPIONs nanoconjugates in saline and in acid media, preventing nanoparticle dissolution in extreme gastric conditions.
Synthesis of all equiatomic five-transition metals High Entropy Carbides of the IVB (Ti, Zr, Hf) and VB (V, Nb, Ta) groups by a low temperature route
(Elsevier, 2020-09) Chicardi Augusto, Ernesto; García Garrido, Cristina; Hernández-Saz, Jesús; Gotor, F. J.; Ingeniería y Ciencia de los Materiales y del Transporte; Universidad de Sevilla; TEP973: Tecnología de Polvos y Corrosión
The six possible equiatomic five-transition metal High Entropy Carbides (HECs) of the IVB (Ti, Zr, Hf) and VB (V, Nb, Ta) groups of the periodic table, i.e., TiZrHfVNbC5, TiZrHfVTaC5, TiZrHfNbTaC5, TiZrVNbTaC5, TiHfVNbTaC5 and ZrHfVNbTaC5, were successfully obtained via a powder metallurgy route at room temperature, specifically, by one-step diffusion mechanosynthesis starting from the elemental constituents (using graphite as the carbon source). Three of those HECs, TiZrHfVTaC5, TiZrVNbTaC5 and ZrHfVNbTaC5, were developed for the first time. Their development was possible without any subsequent thermal treatment, in contrast to the usual way (reactive sintering at 1800–2200 °C), and in a powder form, make them potential advanced raw ceramics for hard, refractory and oxidation resistance coatings or matrix phase composites.
Evaluation of Corrosion Behavior of Zn–Al–Mg-Coated Steel in Corrosive Heterogeneous Soil
(MDPI, 2025-08-20) Lloreda Jurado, Pedro Javier; Chicardi Augusto, Ernesto; Ingeniería y Ciencia de los Materiales y del Transporte; Universidad de Sevilla; TEP973: Tecnología de Polvos y Corrosión
The long-term durability of steel structures in contact with soil remains a critical challenge due to the complex and aggressive nature of many soil environments. This study presents a thorough evaluation of the corrosion resistance and microstructural evolution of Magnelis® ZM430-coated steel exposed to highly aggressive, heterogeneous soils. Gravimetric analysis revealed that the Magnelis® ZM430 coating exhibits low corrosion rates and enhanced initial barrier properties, even under severe soil conditions. Although the literature frequently reports that Zn–Al–Mg coatings outperform conventional hot-dip galvanized coatings, our results highlight that this superiority is not universal and may be limited under highly aggressive, heterogeneous soils. Microstructural characterization by optical microscopy, SEM/EDS, and XRD demonstrated that the as-received coating consists of a homogeneous layer with well-distributed Zn-, MgZn2-, and Al-rich phases. Upon soil exposure, corrosion preferentially initiates in the Mg- and Al-rich interdendritic and eutectic regions, leading to selective phase depletion and localized breakdown of the protective layer. Despite these localized vulnerabilities, the overall performance of Magnelis® ZM430 remains superior, especially during the early stages of exposure. While no direct comparisons were performed in this work, our findings align with previous literature reporting superior performance of Zn–Al–Mg coatings compared to conventional hot-dip galvanized coatings in similar environments. Importantly, the integration of precise corrosion rate data with detailed soil characterization enables accurate prediction of coating service life, allowing for optimized coating thickness selection and proactive maintenance planning. These findings underscore the value of combining advanced Zn–Al–Mg coatings with site-specific environmental assessment to ensure the long-term integrity of buried steel infrastructure.

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