Treballs Finals de Grau (TFG) - Química

URI permanent per a aquesta col·leccióhttps://hdl.handle.net/2445/48525

Treballs Finals del Grau de Química de la Facultat de Química de la Universitat de Barcelona.

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Synthesis and characterization of Pd functionalized UiO-66 and UiO-67 MOFs for C-C Coupling reactions
(2025-06) Zapirain Closas, Naiara; Sanz Nebot, María Victoria; Szilágyi, Petra Agota
Metal-organic frameworks (MOFs) have emerged as versatile porous materials thanks to their tuneable structures and compositional diversity. These features have positioned MOFs as promising candidates for a range of applications, particularly as platforms for heterogeneous catalysts. Among these, their potential to stabilize isolated metal atoms has attracted growing attention, opening new avenues in the development of single-atom catalysts[1]. Previous work carried out within the group of Szilágyi has demonstrated the immobilization of nanoclusters and single atoms of Pd incorporated into UiO-66 type metal-organic frameworks and has tested the catalytic activity of these Pd-laden MOFs in reactions such as the thermal hydrogenation of CO2. It was of interest to look for a reaction that demonstrates the catalytic activity of Pd single atoms embedded in functionalized UiO-66, and to investigate how Pd is incorporated in UiO-67 with new linkers. In this work, new functionalized linkers have been synthesized and incorporated into UiO-66 and UiO-67 MOFs, followed by metalation of the frameworks with Pd. Characterization has been done to confirm the structure of the material, and to understand the speciation of the incorporated Pd. The catalytic performance of the Pd immobilized frameworks for Stille coupling reaction has been assessed and the preliminary results are outlined. Functionalized terephthalic acid-based linkers and BPDC have first been synthesized and integrated into the UiO-66 and UiO-67 topology following an established synthesis protocol[2]. Metalation of these modified MOFs was achieved through the incorporation and subsequent in-situ reduction of a Pd precursor, allowing the integration of neutral Pd atoms within the MOF pores. Comprehensive structural analysis was performed using techniques such as X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer-Emett-Teller (BET) surface area measurements, scanning electron microscopy (SEM), and microwave plasma atomic emission spectroscopy (MP-AES), enabling insights into the distribution and chemical state of Pd. Advanced characterization confirmed that palladium was successfully incorporated into the MOFs in both UiO-66 and UiO-67 type MOFs. BET measurements show that UiO-67 type MOFs have much larger surface area due to the larger size of the linkers used. The catalytic performance of the synthesized UiO-66 type MOFs in the Stille coupling reaction has been examined and confirmed in this work, with the obtention of biphenyl using the synthesized MOFs as catalysts.
Study and optimisation of an α-selective catalytic allylic benzylborylation using Morita-Baylis-Hillman adducts and organoboron pronucleophiles
(2025-06) Villegas Vaquero, Ainhoa; Companyó Montaner, Xavier
Asymmetric allylic alkylation (AAA) is a chemical reaction in which an allylic substrate undergoes substitution by a nucleophile in the presence of a chiral catalyst, leading to the stereoselective formation of a new carbon–carbon or carbon–heteroatom bond at the allylic position. AAA reactions have become one of the most powerful and versatile catalytic strategies for the stereoselective formation of such bonds. For several years, these reactions were predominantly catalysed by transition metals. However, from 2000, many fundamental catalytic processes began to be developed under organocatalytic conditions, including the catalytic AAA using Morita-Baylis–Hillman (MBH) adducts as electrophilic substrates. Since then, significant progress has been made in the development of AAA methodologies. However, most reported AAA reactions involving MBH adducts have focused on achieving γ-selective asymmetric alkylation. In contrast, α-alkylations have been less extensively explored. The main goal of this TFG is the study and optimisation of an α-selective asymmetric allylic benzylborylation using MBH fluorides or MBH carbonates and organoboron pronucleophiles activated via desilylation or deborylation. Building on the knowledge previously acquired by the research group to achieve γ-selective asymmetric allylic benzylborylation, the objective of this TFG is to switch this γ-selectivity to α-selectivity. The most innovative aspect of the process is the use of the leaving group (LG) as a catalytic reaction initiator. The homoallylic benzylborylated product obtained is a valuable intermediate due to the versatile reactivity of organoboron compounds, which can serve as building blocks for the synthesis of other complex organic compounds
Phosphorus ligands with the 1,8-dimethylnaphthalene scaffold
(2025-06) Vila Gaja, Alda; Grabulosa, Arnald
In this TFG, the study of the synthesis of different unreported phosphorus ligands based on the 1,8-dimethylnapthalene core has been carried out focusing on synthetic efficiency. The first part focuses on the synthesis of 1,8-dimethylnaphthalene (5) from naphthalic anhydride (1) involving a variety of synthetic methods and experiments that resulted into an efficient synthesis of 5. This compound has been characterized to ensure its purity to be used for the preparation of a P-phenylphosphorinane (8).Taking advantage of the precursors prepared for the synthesis of 5, two unreported ligands have also been synthesized, which can open the door to other interesting ligands for homogeneous catalysis: a bisphosphinite ligand (6) and an eight-membered cyclic phosphonite ligand (7). Both ligands have been characterized, including the selenide of 7, which allowed the evaluation of its donor properties. In addition, preliminary complexation studies of 7 with palladium(II) and ruthenium(II) precursors have been performed.Finally, the challenging synthesis of a novel 6-membered ring phosphorus heterocycle from precursor 5, the P-phenylphosphorinane 8, has also been performed by cyclisation of dilithiated 5 with dichlorophenylphosphine. Numerous difficulties, modifications, drawbacks and uncertainties had to be faced but it seems that the desired compound has been finally obtained and will be purified in future studies.
Alginate nanoparticles as a novel drug delivery system for Alzheimer's disease treatment
(2025-06) Tanyà Rovira, Sergi; Ignés i Mullol, Jordi; Grijalvo Torrijo, Santiago
Nanotechnology has emerged as a promising approach for developing innovative treatments for neurodegenerative diseases such as AD. The limited effectiveness of current therapies is largely attributed to the poor ability of drugs to cross the BBB. Recent advancements in biocompatible NPs have led to the creation of drug delivery systems (DDS) that offer minimal toxicity, superior BBB penetration, and improved transport of drugs with low water solubility. In this work, the application of ALG NPs for the treatment of AD is considered, with a focus on antioxidant therapy. Using the emulsion method, NPs with optimized properties for brain drug delivery were successfully synthesized. Key formulation parameters were adjusted to achieve a highly biocompatible and stable system, with particle sizes averaging around 12 nm (close to the ideal size for effective BBB penetration). A key aspect of the research involved optimizing surface charge, as positively charged NPs exhibit higher uptake across the BBB. However, attempts to achieve this through surfactant or cationic polymer coatings presented challenges, including undesirable increases in particle size and polydispersity. Ferulic acid (FA), a phytochemical with potent antioxidant activity, was selected as a model drug. Its successful encapsulation and loading into the NPs were confirmed using HPLC, demonstrating the system’s effectiveness in drug incorporation. To enhance therapeutic specificity, the NPs were functionalized with mitochondrial-targeting ligands. Of the ligands tested, (3-carboxypropyl)-triphenylphosphonium bromide (TPP) showed the most promising results. In contrast, the synthetic dendrons “G1” and “G2” faced significant solubility limitations and resulted in low functionalization yields. The most efficient strategy for ligand attachment proved to be the pre-functionalization of ALG before NPs synthesis. Although further optimization and comprehensive biological evaluation are necessary, the findings of this study establish a solid foundation for future research in the development of targeted nanotherapeutics for neurodegenerative diseases like AD.
Synthesis and kinetics of photoisomerization processes of water soluble Pd(II) and Pt(II) compounds
(2025-06) Ramírez Valladares, Gerardo; Ferrer García, Montserrat
This study focuses on the synthesis and characterization of water-soluble square-planar Pd(II) and Pt(II) complexes containing azobenzene ligands, specifically 4-phenylazopyridine (Phpy) and 4-aminoazopyridine (Ampy), with the aim of studying the cis-trans isomerization mechanism of the azo ligand coordinated to the metal center. Once the indicated azo derivatives were synthesized and characterized, the corresponding Pd(II) derivatives [Pd(TMEDA)(Ampy)2](NO3)2 and [Pd(TMEDA)(Phpy)2](NO3)2 were obtained through substitution reactions. In the case of [Pd(TMEDA)(Ampy)2](NO3)2, an equilibrium is observed when dissolved in water, whereas for [Pd(TMEDA)(Phpy)2](NO3)2, exhibits this phenomenon in water and methanol. To prevent the observed de-coordination, Pt(II), a more inert metal center than Pd(II), was employed. However, when the square-planar complex [Pt(TMEDA)(NO3)2] was reacted with the Ampy ligand under the same conditions used for Pd(II), the desired Pt(II) diazo complex could not be obtained. Despite the de-coordination equilibrium, the kinetics of the cis-trans isomerization of the diazo complex [Pd(TMEDA)(Phpy)2](NO3)2 and the corresponding Phpy ligand were studied by UV/Vis spectroscopy and the apparent rate constants as well as the activation parameters ΔH‡ and ΔS‡ were determined. Unfortunately, for the [Pd(TMEDA)(Ampy)2](NO3)2 the cis-trans isomerization process resulted so fast that it could not be monitored with the equipment available in the laboratory
Synthesis of coordination complexes using nitrogenated macrocycles. Magnetic study
(2025-06) Pérez Izquierdo, Paula; Mayans Ayats, Júlia
“In the last decade, S=1/2 systems of Cu (II) complexes and Cu (II) ions in the solid state have been found to exhibit slow magnetic relaxations. With the aim of progressing toward the entanglement of spin states and quantum computing using spin qubits, a greater number of studies on molecule-based spin qubits that exhibit magnetic interactions will be conducted and will be of increasing importance from now on.” (2) Nickel (II), similarly to copper (II), is a transition metal cation that can show interesting magnetic behaviour when is coordinated with suitable ligands. With an electronic configuration of d8, Ni (II) tends to form stable octahedral geometries, where the presence of unpaired electrons contributes to the magnetic susceptibility of the complex. In polynuclear systems, Ni (II) allows the study of magnetic interactions such as antiferromagnetism, especially when metal centres are connected through bridging ligands like oxalate. Also, its smaller contribution to the Jahn-Teller effect compared to Cu (II) usually results in less distorted structures, which makes the structural and magnetic analysis easier to interpret. (3) This project is focused on the synthesis of new coordination compounds using copper (II) and nickel (II) salts with nitrogenated macrocycles as ligands, combined with oxalate or benzoquinone bridges. The main objective is to create and study these complexes for their potential magnetic properties, with possible future applications in molecular magnets or quantum technologies. During the project, six different compounds were successfully synthesised and characterized. The ligands used (232-N4 and 323-N4) helped to build coordination structures with varying geometries. Techniques like IR spectroscopy and X-ray diffraction were used to analyse their structures. In parallel, their magnetic behaviour was studied using SQUID magnetometry, which allowed precise measurements of magnetization and magnetic susceptibility. Additionally, Electron Paramagnetic Resonance (EPR) was carried out. The complexes showed interesting structural details and magnetic patterns depending on their composition. Concepts such as magnetization, susceptibility, and anisotropy of the g-factor are essential to interpret the results correctly. Through these analyses, it is possible to relate geometric features of the complexes with their magnetic responses, which is a key aspect in the field of molecular magnetism. Although some reactions didn’t give products (which are in the appendix 1), the project contributed valuable knowledge. It supports basic research in coordination chemistry and molecular magnetism, which can be useful in high-density data storage, quantum computing, or advanced sensors in the future
Elucidation of the Biosynthesis of Rickiols
(2025-06) Novo Blazquez, Alexia; Cox, Russell; Gerlach, Nick
Rickiols are a novel class of fungal macrolides with promising antibiotic properties, particularly against Gram-positive bacteria. Despite their structural elucidation in 2017, the genes responsible for their biosynthesis in the filamentous fungus Hypoxylon rickii remained unidentified. This thesis aims to elucidate the biosynthetic gene cluster (BGC) of Rickiols and functionally validate it via heterologous expression in Aspergillus oryzae, through molecular cloning and transformation. The genes encoding core enzymes, such as highly reducing polyketide synthase (hrPKS), thioesterase (TE); and genes encoding tailoring enzymes like cytochrome P450, short-chain dehydrogenase/reductase (SDR), and flavin-dependent monooxygenase (FMO), were introduced into A. oryzae using synthetic biology tools. The expression of these genes led to the successful production of several Rickiols. The presence and chemical structures of the new compounds was confirmed by HPLC-MS and NMR. These findings lay the groundwork for the future development of scalable microbial production systems that could be used to generate new antibiotics or chemical variants with enhanced therapeutic potential, avoiding the need for chemical synthesis
Identification of phytoestrogens in protein products from an alfalfa biorefinery
(2025-06) Ganesio Vega, Joan David; Benavente Moreno, Fernando J. (Julián)
Biorefineries are complex processing facilities dedicated to the sustainable transformation of biomass into value-added products. This project studies the influence of biorefinery processing conditions on the phytoestrogen composition of protein products derived from Medicago sativa L., commonly known as alfalfa. This leguminous plant has been traditionally used as a forage and is now gaining attention for its potential in producing proteins for human consumption. Phytoestrogens are bioactive secondary metabolites present in leguminous plants. Their structural similarity to the mammalian estrogen 17β-estradiol allows them to bind to estrogen receptors in animals. Given their capacity to produce both beneficial and adverse biological effects, identifying these compounds in alfalfa-derived products is critical to ensure consumer safety. Ten alfalfa samples obtained from an industrial-scale biorefinery developed by Contento Trade Srl (Italy) were analyzed. These included nine mixed-protein and one fresh alfalfa samples, processed under varying conditions, including different harvest lots, drying delays, and drying techniques. Compound identification in the studied samples was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS), supported by a custom-built database of phytoestrogens and related metabolites. Cross-referencing the obtained analytical data with the database enabled the tentative identification of 24 phytoestrogens across the samples. Comparative analysis showed that biorefinery processing conditions significantly affected the phytoestrogen profile of the mixed-protein products. Environmental stress factors affecting the fresh alfalfa material, such as morning frost exposure prior to harvest, altered these profiles. Regarding the biorefining drying conditions of the extracted mixed-proteins juice, delayed dryings of 16 or 36 hours were associated with higher phytoestrogen levels, indicating that immediate drying is preferable. In contrast, the drying technique (i.e. spray-drying or freeze-drying) had no significant effect on the final phytoestrogen composition. This finding supports the use of spray-drying as a more sustainable option for the biorefinery operation, given its lower energy and time requirements
Towards the synthesis of chiral benzofused cycloalkanes through iridium catalyzed asymmetric hydrogenation
(2025-06) Belmonte Navarro, Noa; Verdaguer i Espaulella, Xavier; Sidro Inglés, Martí
Enantioenriched chiral organic compounds, such as benzofused cycloalkanes, are key structures present in a large number of biologically active compounds, like natural products or pharmaceuticals. To answer this demand, asymmetric synthesis has gained a lot of interest in the last few years. So far, asymmetric hydrogenation has become one of the most relevant methodologies in the field, given its many benefits. However, it is still underdeveloped as a strategy for the synthesis of benzofused cycloheptanes. Motivated by this, our group has worked on developing a new methodology towards the synthesis of these chiral compounds, through an iridium catalyzed asymmetric hydrogenation. In this work, a benzofused methylene cycloheptane has been synthesized, and its asymmetric hydrogenation studied using different Ir-catalysts. Moreover, kinetic studies were conducted in order to analyze the effect of different catalysts in the isomerization process of the substrates. The results obtained led to the preparation of a new catalyst, Ir-NoaPHOX, that proved optimal by affording no isomerization process. Finally, Ir-NoaPHOX was tested on the asymmetric hydrogenation of benzofused methylene cycloheptanes, providing an enantiomeric excess of 89%. Additionally, derivate benzofused methylene cycloheptanes substrates were prepared, to broaden the scope of the methodology
Development and validation of NIRS calibrations for the analysis of additives in animal nutrition products
(2025-06) Andrés Bedmar, Júlia; Gargallo Gómez, Raimundo; Aguilar Reina, Josefa
This final degree project focuses on the application of Near-Infrared Reflectance Spectroscopy (NIRS) as an alternative analytical technique to traditional methods for the analysis of additives intended for animal nutrition. It is a fast and non-destructive analytical technique that is becoming increasingly relevant in this industrial sector. The main objective of this project is to design multivariate calibration models using NIRS, applying the mathematical methods mPLS and PCA, for the determination and quantification of various parameters, such as moisture and antioxidant content. To achieve this objective, a robust database was built by analyzing the maximum number of available samples and assigning to each sample the reference values obtained using traditional analytical techniques, such as coulometric titration for moisture determination using Karl Fischer and gas chromatography (GC) for the quantification of different types of antioxidants. Once all data were entered into the system, predictive models were developed using specific software, with the aim of correlating the NIRS spectra obtained from the analysis of the samples with their corresponding reference values. Subsequently, the models were validated through the analysis of new samples, assessing their accuracy, precision, and robustness. Deviations were also identified and corrected to improve the prediction model. The results obtained showed a high correlation (R² > 0.95) and low prediction errors, lower than those associated with traditional analytical methods, both in the determination of moisture and in the quantification of the two types of antioxidants, demonstrate the viability of NIRS as an alternative analytical method
The effect of nanoparticles on the physicochemical and thermal properties of different organic eutectic mixtures
(2025-06) Tovar Pichardo, Lucas; Svobodova Sedlackova, Adela; Salgado Pizarro, Rebeca
This final project investigated the effect of SiO2 nanoparticles on the thermal and physicochemical properties of various organic eutectic mixtures, with the aim of improving their properties for application in phase-change materials (PCMs) for energy applications. PCMs are compounds with a high capacity to store and release thermal energy during phase-change processes, making them key materials for achieving greater sustainability and energy efficiency in various sectors such as construction, electronics, and thermal storage systems. A total of five binary eutectic mixtures consisting of fatty acids and esters were synthesized: capric acid/ethyl stearate (CA/ES), capric acid/ethyl myristate (CA/EM), capric acid/methyl palmitate (CA/PM), ethyl myristate/palmitic acid (EM/PA), and capric acid/palmitic acid (CA/PA). However, only three of them (CA/PA, CA/EM, and CA/ES) were fully characterized due to reagent availability issues. Eutectic concentrations were determined by differential scanning calorimetry (DSC) using the STARe Evaluation program, selecting those ratios that showed a single melting peak in the thermogram. From these, modified versions containing 1% by weight of SiO2 nanoparticles were prepared and dispersed using ultrasound. The samples were characterized using differential scanning calorimetry (DSC) to determine their enthalpy of fusion and heat capacity (cp) and using the Hot Disk method to evaluate their thermal conductivity. The results indicate that the addition of nanoparticles increases cp and thermal conductivity, while the enthalpy of fusion decreases. The latter property presents negative values, as it is an endothermic process in which the material absorbs heat to change phase. The main experimental limitation arose when attempting to measure the thermal conductivity of the CA/PA and CA/ES eutectics. Since their melting temperatures were close to the test temperature, the energy released by the sensor caused the compounds to melt, invalidating the results. In conclusion, the results obtained show that the incorporation of SiO2 nanoparticles modifies the thermal properties of the PCMs studied, suggesting a potentially positive impact on their efficiency and use in practical applications. Among these, the most notable uses are in construction materials, electronic components, and thermal energy storage systems, where improved thermal conductivity and thermal stability can provide significant benefits.
Visible-Light-Induced Functionalization of Oxindole Enol Ethers via EDA Complex Photoactivation
(2025-06) Santiago Abelleira, Danae; Vega Peñaloza, Alberto
Light-mediated reactions offer a powerful platform for exploring chemical reactivity through controlled photoexcitation. This project focuses on advancing photoinduced reactions via electron donor-acceptor (EDA) complex activation, where interactions between an electron-rich donor and an electron-deficient acceptor generate reactive radicals under visible-light irradiation. Crucially, this approach operates without external catalysts—such as traditional metal-based photocatalysts—or sacrificial additives, enhancing synthetic efficiency. Central to our study is the functionalization of oxindoles, a privileged scaffold in medicinal chemistry due to the potent bioactivity of its derivatives. To achieve this, we designed and synthesized an oxindole-derived enol ether (donor 1) and paired it with Katritzky salts (acceptors 3 and 4) as complementary EDA complex partners. UV-visible spectroscopy confirmed EDA complex formation through the characteristic charge-transfer band (CT), while also identifying the optimal irradiation wavelength to maximize product formation and minimize byproduct generation. These findings establish a foundation for developing a mild, efficient, and catalyst-free methodology for oxindole functionalization. Future work will expand the scope of this reactivity and refine reaction conditions to enhance synthetic utility.
Allylic C–H functionalization reactions for the cyclization of hemisilaketals
(2025-06) Gimeno Gas, Meritxell; Ariza Piquer, Xavier
Polyhydroxylated compounds are among the most valued in organic chemistry due to their biological activity and, consequently, their pharmaceutical potential. 1,3-Diols are structural motifs commonly found in therapeutically significant drugs, such as statins. Therefore, the development and optimization of efficient synthetic methods to obtain them represent an important challenge. This is a constantly evolving field of research among other reasons, due to the difficulty in achieving stereoselectivity. This project focuses on the synthesis of these valuable moieties based on allylic C–H activation, a less studied strategy for C–O bond formation. The formation of hemisilaketals leads to silaketals through a rhodium-catalyzed cyclization. Finally, a deprotection step is required to obtain stereoselective syn-1,3-diols, as depicted in the general scheme below. The synthesis and characterization of syn-1,3-diols has been accomplished from various substrates. This project also reports modifications to the synthetic pathway that enhance efficiency and yield higher-purity products. The methodology has been established as an effective and reproducible route for the stereoselective synthesis of the desired compounds. Furthermore, the range of possibilities for accessing these valuable compounds has been expanded, offering an alternative approach.
Optimization of Preparation Methods and Thermal Characterization of Nanofluids Based on Solar Salts for Thermal Energy Storage
(2025-06) Georgieva Kashkavaldzhieva, Ioana; Svobodova Sedlackova, Adela; Neira Viñas, Marc
It is well known that thermal power plants used to generate electricity from heat have an extremely negative impact on the environment. To produce energy, coal, gas, or oil is used, which, after being burned, emit toxic gases. As a result, the accumulation of these greenhouse gases intensifies global warming, contributing to the climate change. For this reason, more and more CSP (Concentrated Solar Power) plants are being developed today to generate energy and serve as a cleaner alternative to replace traditional thermal plants. CSP plants concentrate sunlight to generate heat, which is stored in insulated tanks containing molten salts. The stored heat is later released when electricity needs to be generated. To improve the thermal properties of molten salts, doping with nanoparticles has proven to be the most optimal technique. Several studies have shown that nanofluids containing 1% by weight of nanoparticles significantly increase thermal efficiency and offer major advantages as thermal energy storage (TES) media. However, one of the main disadvantages of nanofluids is the lack of a clear theoretical explanation of their behavior, as existing models do not always fully explain experimental results. For this reason, the aim of this study was to analyze how different parameters, such as the amount of water used to dissolve the salt, sonication time, and water evaporation temperature of the nanofluid affect the thermal properties of a nanofluid composed of NaNO₃ salt and SiO₂ nanoparticles (1% by weight). Two synthesis methods were used: wet and dry. For the wet method, 7 batches were prepared, each containing 9 samples. For the dry method, 4 batches were synthesized, each with 2 samples. Analysis of the results showed that the nanoparticles have a low impact on enthalpy and thermal conductivity but do have a significant influence on increasing the specific heat capacity (cp). The dry method, which involves synthesis through ball milling, stood out as an effective way to create nanofluids with a high specific heat capacity. The main objective of this work was to develop new techniques for the synthesis of nanofluids and to find a way to improve the experimental procedure by optimizing various parameters.
Controlling supramolecular organization and chiral assembly of functional molecules using heparin
(2025-06) Torrades Violán, Martí; Kumar, Mohit
The controlled assembly of π-conjugated molecules in water represents a key strategy in the development of functional supramolecular materials. This work presents the synthesis of a series of positively charged achiral molecules and explores their ability to self-assemble with negatively charged biomolecules, particularly heparin, in aqueous medium. The aim was to investigate how the binding of a biomolecule like heparin, along with other non-covalent interactions, drive the formation of functional supramolecular nanomaterials and how the chiral nature of heparin induces supramolecular chirality in the assembly of achiral molecular systems. The resulting supramolecular assemblies were characterized using ultraviolet-visible (UV-Vis) absorption, fluorescence, circular dichroism (CD) spectroscopies as well as transmission electron microscopy (TEM). We demonstrated that the binding of heparin resulted in the formation of helical nanostructures with distinct absorption and fluorescence properties and chiroptical activity. These findings demonstrate that the interaction between cationic achiral molecules and chiral polyanions not only enables the formation of well-defined nanostructures but also activates functional optical responses. It can be concluded that this strategy provides a promising platform for a) controlling supramolecular assembly of functional molecules; b) the design of responsive materials for the optical detection of biologically and biomedically relevant molecules
Characterization of FFF printed parts made of 3Y-TZP and Al2O3 filaments
(2025-06) Pozuelo Riera, Eloi; Padilla Sánchez, José Antonio; Xuriguera Martín, María Elena
This study focuses on determining the optimal thermal treatment conditions for YSZ and Al₂O₃ samples manufactured using 3D printing technology through Fused Filament Fabrication (FFF), with the aim of achieving superior mechanical and microstructural properties while addressing known issues such as Low Temperature Degradation (LTD) in the case of YSZ. Thermogravimetric analysis (TGA) guided the design of the thermal profiles to ensure controlled removal of organic binders without compromising the structural integrity of the samples. Mass loss and volumetric shrinkage were characterized, confirming that the debinding process removes most of the organic components, while sintering promotes densification. Densification and porosity results were in good agreement with the specifications provided by the supplier (Zetamix) for YSZ, especially after one hour of sintering at 1500 °C, whereas alumina samples showed partially divergent trends, likely due to limited processing conditions. Flexural strength tests revealed that alumina samples closely matched the mechanical performance predicted by Zetamix, while YSZ samples showed lower values due to the presence of microcracks, as confirmed by SEM analysis. Rheological characterization showed a desirable shear-thinning behavior and appropriate yield stress values for both ceramic filaments, confirming their suitability for extrusion-based additive manufacturing. Microstructural studies using FE-SEM and EDS detected alumina inclusions in the YSZ samples, possibly related to mechanical defects, while alumina samples showed homogeneous microstructures with larger grain sizes correlating to higher strength. Overall, this study highlights the critical role of thermal process control in balancing densification, microstructure, and mechanical properties. The results support the potential of these ceramic materials for demanding functional applications, with special emphasis on biomedical implants such as hip prostheses. Further research is recommended involving advanced microstructural analysis, broader mechanical testing, and optimization of 3D printing parameters to mitigate defects and improve final part performance
Analysis of the present and prediction of the future of Li batteries applied to electric transport vehicles
(2025-06) L’Harrak L’Harrak, Fatima Zahrae; Cabot Julià, Pere-Lluís
Conventional combustion cars are a problem due to their high CO₂ emissions. It has been calculated that a quarter of carbon dioxide emitted by human activities comes from transport vehicles. The objective is to decarbonize vehicles by electrifying them with the use of lithium batteries as an energy source that allows their mobility to evolve towards a more sustainable future. The bibliographic analysis shows the different types of lithium batteries that can be useful in vehicles and the forecast of the evolution according to the different scenarios, costs, available materials and performance. Lithium-ion batteries are the most used currently and vary according to the composition of the cathode. The most prominent currently are NMC (nickel-manganese-cobalt) and LFP (lithium iron phosphate) There are also other types of lithium batteries that are used less often, such as Li-polymer, which are one of the options used in some light electric vehicles. Emerging technologies and innovations are key to developing Li-ion batteries with materials that can improve consumption thanks to the positive evolution of the economy and availability. Seeing the evolution of prices of components such as nickel and cobalt, vehicles with LFP batteries are increasingly being chosen. There are several alternatives to try to achieve different objectives. A more economical way would be to replace Li+ with Na+ (Na-ion batteries). Another possibility for improvement would be Li-S batteries due to their performance. This type of battery has a greater energy capacity, favoring high efficiency. To focus on the possibility of evolution towards the change from combustion vehicles to implementing lithium batteries in electric vehicles, it is necessary to take into account electrochemistry, sustainability, the possibility of obtaining essential materials for their production and above all the cost they would have on the market.
Occurrence and effects of antibiotics on the environment
(2025-06) Hernández Dominich, Laia; Cruz Alcalde, Alberto; Llorca Casamayor, Marta; Farré Urgell, Marinella
Antibiotics are one of the most significant discoveries of the 20th century, but over the last few years, a new problem has emerged due to their excessive use and persistence in the environment. The presence of these drugs in ecosystems has led to the spread of antimicrobial resistance, prompting the World Health Organization to warn that by 2050, if nothing changes, 10 million deaths caused by bacterial infections could be reached. For this reason, this study analyzes the occurrence of antibiotics in aquatic environments to determine their risk in ecosystems and for antimicrobial resistance. Different samples from river, sea and around wastewater treatment plants (WWTPs) in Barcelona, Valencia (Spain), Paris (France) and Helsinki (Finland), areas of considerable interest due to their anthropogenic impact and different climate conditions, were examined to determine the occurrence of antibiotics by HPLC-HRMS, using either target analysis focused on 18 antibiotics and suspect screening for the identification of other drugs. The results obtained were used to perform a statistical analysis of environmental factors and to evaluate ecotoxicological risk using the Hazard Quotient. The most frequently detected antibiotics with the highest risk were sulfamethoxazole, metronidazole, azithromycin and tetracycline. On the other hand, the highest concentrations were found in samples near WWTPs, while sea samples have the lowest concentrations due to the dilution effect. Finally, this study shows that these drugs could represent a significant risk to aquatic ecosystems, as in several cases they exceed environmental risk thresholds, demonstrating the need for improved removal treatments for these substances and stricter environmental regulation
Preparation of methanol reforming catalysts by Atomic Layer Deposition (ALD)
(2025-06) Graell Hernández, Carles; Guilera Sala, Jordi; Martin Morales, Elena
Methanol Steam Reforming (MSR) is of particular interest for fuel cell applications and integrated hydrogen production systems, both as a transportation fuel and for industrial applications, given methanol’s favorable characteristics as a hydrogen carrier. CuO/ZnO/Al₂O₃ (CZA) catalysts for MSR have been widely employed due to their high activity, selectivity, and stability under reaction conditions. This study investigates the synthesis and performance of CZA catalysts for MSR, with a focus on minimizing ZnO content and evaluating Atomic Layer Deposition (ALD) as an alternative to conventional preparation methods. Catalysts with fixed CuO loading and varying ZnO content were prepared by wet impregnation and ALD, and were characterized using XRD, N₂ physisorption, and H₂-TPR. Catalytic activity was assessed in MSR reactions between 250–350 °C. Results revealed that a low ZnO loading (1 wt%) provided favorable textural properties, while the highest methanol conversion was achieved with 10 wt% ZnO. ALD-prepared catalysts demonstrated improved stability and activity at moderate temperatures, along with lower CO selectivity, highlighting the potential of ALD for enhancing catalyst performance.
Modification of 2D Graphene Membranes for Biogas Enrichment Using Machine-Learning Force Fields
(2025-06) Garrrote Ferré, Biel; Viñes Solana, Francesc; Gamallo Belmonte, Pablo
The present project explores the use of grazynes, two-dimensional (2D) carbon allotropes nanoengineered with nanopores, as an innovative solution for separating CO₂ and CH₄ in biogas. This is achieved by performing substitutions of the hydrogen atoms originally located at the pore sites with different halogens (F, Cl, and Br). The system is assessed through theoretical simulations using Density Functional Theory (DFT), employing the Perdew–Burke–Ernzerhof (PBE) exchange-correlation functional, and including dispersive interactions via the Grimme D3 method (PBE-D3). The analysis focused on the diffusion of CO₂ and CH₄ through the pores of various halogenated grazynes. Adsorption energies and penetration energy barriers for both molecules were calculated, revealing that CO2 exhibits low adsorption and diffusion barriers, while CH₄ shows also low adsorption energies, but with significantly higher barriers. This implies that fluorinated grazynes are promising candidates for biogas upgrading. However, chlorine and bromine substitutions increase the atomic radius at the pore, reducing permeability and making these materials unsuitable for gas separation. Subsequently, diffusion rate constants were computed using Transition State Theory (TST), confirming that only fluorinated grazynes present large enough rate constants (k), indicating effective gas permeation, while chlorinated and brominated grazynes yield values close to zero, highlighting their poor performance as separation membranes. Thus, CO₂ could be largely selectively separated when using defective [1],[2]{2}-tetrafluorograzyne, specially when goes through various penetration cycles. The [1],[2]{2}-fluorograzyne and [1],[2]{2}-o-difluorograzyne were subjected to further study via Molecular Dynamics (MD) simulations using Machine-Learning Force Fields (ML-FF). Although the force field exhibited low training errors, the MD trajectories displayed chemically unrealistic behaviour, e.g. bent CO₂, implying that the model had not been exposed to a sufficiently diverse training set. Thermodynamic plots showed a sudden increase in temperature and energy during the simulation, which confirms that the system adopted unrealistic atomic configurations. Therefore, the force field must be trained with more data to ensure accurate and reliable MD-MLFF results.

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