Articles publicats en revistes (Institut de Nanociència i Nanotecnologia (IN2UB))

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Tuning luminescence in gold(I)-phosphine complexes: structural, photophysical, and theoretical insights
(Royal Society of Chemistry, 2025-01-22) Atencio, P. Anyie; Burguera, Sergi; Zhuchkov, George; Aquino Samper, Araceli de; Ward, Jas S.; Rissanen, Kari; Lima, João Carlos; Angurell Purroy, Inmaculada; Frontera, Antonio; Rodríguez Raurell, Laura
Gold(I) complexes featuring phosphine ligands functionalized with chromophores such as triphenylene, phenanthrene, and carbazole were synthesized and systematically studied to explore the relationship between molecular structure and luminescence properties. Comprehensive photophysical characterization revealed that the coordination environment and chromophore positioning significantly influence intersystem crossing, phosphorescence, and aggregation behavior. In solution, aggregation-induced phenomena were probed using computational tools, including density functional theory (DFT) and noncovalent interaction (NCI) analysis, revealing diverse π-stacking and Au⋯π interactions. Distinct photophysical trends were identified among the three series of compounds, with triphenylene derivatives exhibiting aggregation-induced emission broadening and phenanthrene derivatives showing strong heavy atom effects. The combination of experimental and theoretical insights provides a foundation for designing luminescent materials with tunable properties for optoelectronic applications.
Optimizing energy storage: Carbon implantation in NiO matrix unveils C–NiO's hybrid capacitive and battery-like behavior with enhanced electrochemical performance
(Elsevier B.V., 2024-03-19) Shafique, Muhammad Ahsan; Farid, Ghulam; Shaheen, Fozia; Zaheer, Zeeshan; Murtaza, Ghulam; Sharif, Sadia; Ahmad, Riaz
Doping is a common strategy employed to enhance material properties. Numerous researchers have introduced carbon into the nickel oxide (NiO) matrix through various methods to improve the electrochemical performance for energy storage applications. This study investigates the impact of carbon implantation into the NiO matrix using a particle accelerator. Cyclic voltammetry profiles of carbon-implanted NiO (C–NiO) reveal distinct oxidation–reduction peaks, and one side of the CV curves exhibits a rectangular shape, confirming the hybrid capacitive and battery-like behavior of C–NiO. The reduced separation between oxidation–reduction peaks and the increased specific capacitance at higher scan rates validate the capacitive nature of C–NiO. Enhanced electrochemical performance was further explored through GCD, EIS, and BET techniques. C–NiO demonstrates impressive capacitance retention of 93.8 % after 5000 cycles. The Nyquist plot indicates that the improved performance of C–NiO is attributed to its heightened electrode activity, resulting from lower charge-transfer resistance. BET analysis confirms that C-doping leads to a larger surface area. In the NiO matrix, two bands of adsorbed CO2 are observed, whereas these bands are absent in C–NiO, indicating clearer pathways for ion–electron exchange. Compared to undoped NiO (55 F/g at 50 mV/s), C–NiO exhibits a more than tenfold increase in specific capacitance (1079 F/g at 50 mV/s).
Rapid and simple dual extraction for the analysis of lipids and autoantigenic peptides within phosphatidylserine-liposomes
(Elsevier B.V., 2024-08-13) El Ouahabi, Oumaima; Mancera Arteu, Montserrat; Latorre, Irene; Salvadó, Míriam; Rodríguez-Vidal, Sílvia; Sanz Nebot, María Victoria
Autoimmune diseases are a major health concern in developed countries. Currently, only palliative treatments based on anti-inflammatories and immunosuppressors are available. A novel antigen-specific therapy that uses a physiological process of tolerance generation is being developed. This is plausible by using phosphatidylserine rich liposomes (PS-liposomes), which bio-mimic apoptotic cells, encapsulated with the autoantigen responsible of generating the autoimmunity. In this way, tolerance against the own cells or tissues that were considered hostile can be achieved. In addition, only by changing the encapsulated peptide, different autoimmune diseases can be treated. Efficacy of this approach was demonstrated in type I diabetes, rheumatoid arthritis, multiple sclerosis, and myasthenia gravis. In the regulatory pre-clinical phase, analytical methodologies to evaluate the quality of the product need to be developed. In this regard, identification and quantification of the encapsulated peptide and lipids are considered critical quality attributes. In this study, a rapid and simple liquid–liquid extraction procedure, based on Bligh-Dyer method, is described for dual extraction of peptides and lipids within PS-liposomes formulation. This single step allows the separation of lipids and the encapsulated peptide in two different phases. For the subsequent analysis, two different HPLC methods were developed. The organic phase, which contains the lipids was analysed by HPLC-ELSD, while the aqueous phase, containing the encapsulated peptide, was analysed by HPLC-UV. Both methods were also validated in terms of accuracy, precision, linearity, LOD and LOQ. The extraction procedure has demonstrated highly efficient separation of lipids and peptides, avoiding interferences between them in the quantification.
Enhanced Selective Contact Behavior in a-Si:H/oxide Transparent Photovoltaic Devices via Dipole Layer Integration
(Wiley-VCH, 2024-06-14) López García, Alex; Álvarez Suárez, Gustavo; Ros Rahola, Emilio; Ortega Villasclaras, Pablo Rafael; Voz Sánchez, Cristóbal; Puigdollers i González, Joaquim; Pérez Rodríguez, Alejandro
Transparent photovoltaic (TPV) devices have the potential to revolutionize photovoltaic (PV) technology by enabling on-site generation while minimizing visual impact. However, a major challenge in the development of TPV, as well as for many PV technologies, is the open-circuit voltage (Voc) deficit, which limits their efficiency. In this work, the development of wide-bandgap inorganic-based TPV devices is reported with a focus on low-cost, earth-abundant, stable, and nontoxic materials. The device structure consists of an ultrathin hydrogenated amorphous silicon (a-Si:H) absorber and metal-oxide layers as selective contacts. Herein, novel approach is presented to significantly improve device performance, especially in Voc, by introducing molecular dipoles in the device electron transport layer. By incorporating polyethyleneimine or poly(amidoamine) G1 and G2 dipoles, Voc (from 410 mV up to 638 mV) is significantly increased without sacrificing the average photopic transmittance of the device, leading to a record efficiency for this particular approach in TPV. Measurements confirm excellent long-term stability. This approach can potentially allow tuning the work function of the selective contacts enabling the use of low-cost, earth-abundant materials that are not optimized for a particular absorber. Furthermore, this solution circumvents the issue of low Voc by a simple interface treatment.
Exploring the Limits and Balancing Efficiency, Transparency, and Esthetics in Ultrathin a-Si:H Transparent Photovoltaic Devices
(Wiley-VCH, 2025-01-08) Álvarez Suárez, Gustavo; López García, Alex; Estarlich, Pau; Asensi López, José Miguel; Masmitjà, Gerard; Ortega, Pablo; Voz Sánchez, Cristóbal; Puigdollers i González, Joaquim; Pérez Rodríguez, Alejandro
Transparent photovoltaic (TPV) devices represent a promising advance in photovoltaic technologies, particularly in building-integrated photovoltaics (BIPV). Unlike conventional photovoltaics, which primarily prioritize efficiency, TPV must balance between efficiency, transparency, and aesthetics. These additional dimensions introduce unique challenges on device architecture. This article reports the development of wide-bandgap, inorganic-based TPV devices integrating ultrathin hydrogenated amorphous silicon (a-Si:H) as a transparent absorber, with carrier selective contacts and transparent electrodes. The article analyzes how absorber thickness influences the electrical, optical, and aesthetic performance of devices, evaluating key parameters in TPV such as light utilization efficiency (LUE), average photopic transmittance (APT), color rendering index (CRI), and electrical properties such as power conversion efficiency (PCE). The device structure is SLG/FTO/AZO/a-SiCx(n)/ a-Si:H/V2Ox/AZO. This approach results in PCE ranging from 1.7% with an APT of 60% to a PCE of 4.1% with an APT of 28%, yielding LUE values between 0.9% and 1.3%. Device characterization encompasses optical spectrophotometry, J–V measurements under standard test conditions, spectral response analysis, and variable illumination measurements (VIM). Additionally, color characterization is conducted using CIE 1931 color space maps to determine the chromaticity coordinates, CRI, and the variation of color as a function of absorber thickness.
Bioorganic activated carbon from cashew nut shells for H2 adsorption and H2/CO2, H2/CH4, CO2/CH4, H2/CO2/CH4 selectivity in industrial applications
(Elsevier Ltd., 2024-10-11) Serafin, Jarosław; Farid, Ghulam; Dziejarski, B.; Fonseca-Bermúdez, Ó.J.; Giraldo, L.; Sierra-Ramírez, R.; Gil Bonillo, Marta; Moreno-Piraján, J.C.
This research explores the production of activated carbon (AC) from cashew nut shells using a potassium hydroxide (KOH) activation method, with a focus on its application in high-pressure gas adsorption. Among the synthesized samples, AC850 demonstrated the highest efficiency, displaying a specific surface area of 1972 m2/g and total and micropore volumes of 0.847 cm3/g and 0.724 cm3/g, respectively. The bioorganic activated carbon exhibited significant sorption capabilities for H2, with uptake values of 13.34 mmol/g (2.69 wt%) at 10 bar and 25 °C, and a H2/CH4 selectivity range between 43.4 and 2.6. Calculations were also conducted for selectivity in a mixture of three gases (H2, CO2, and CH4) in industrial settings. Advanced characterization methods such as N2/CO2 adsorption isotherms, FT-IR, Raman spectroscopy, SEM, and TGA were employed to analyze the structural and chemical properties of the produced AC, including its functional groups and molecular structure. The research underscores the potential of utilizing agricultural waste, particularly cashew nut shells, to develop efficient materials for H2 storage and purification. The high-pressure adsorption capability and eco-friendly nature of the manufactured activated carbon make it suitable for both environmental and industrial applications.
Cashew nut shell biomass: A source for high-performance CO2/CH4 adsorption in activated carbon
(Elsevier, 2024-05-01) Serafin, Jarosław; Gil Bonillo, Marta; Farid, Ghulam; Fonseca-Bermúdez, Ó.J.; Giraldo, L.; Sierra-Ramírez, R.; Dziejarski, B.; Moreno-Piraján, J.C.
This study embarks on the synthesis of activated carbon (AC) from cashew nut shells using a potassium carbonate (K2CO3) activation process, with a specific focus on its practical application in high-pressure gas adsorption. Among the synthesized samples, MCAK85 emerged as the most efficient, demonstrating a specific surface area of 1693 m2/g and total and micropore volumes of 0.839 cm3/g and 0.641 cm3/g, respectively. Importantly, this bioorganic activated carbon exhibited high sorption capacities for CO2 and CH4, with uptake values of 11.0 mmol/g and 5.5 mmol/g at 10 bar at 25°C, and a CO2/CH4 selectivity range between 9.1 and 1.8. A comprehensive range of characterization techniques were employed to analyze the structural and chemical properties of the synthesized AC, providing valuable insights into the functional groups and molecular structure. The morphology of the AC was examined using SEM, while the point of zero charge was determined to understand the surface charge characteristics. Additionally, TGA was utilized to assess the thermal stability and composition of the AC. This study underscores the potential of utilizing agricultural waste, specifically cashew nut shells, in the creation of effective materials for gas storage and purification applications. The high-pressure adsorption capacity of the produced AC, coupled with its sustainable and eco-friendly nature, underscores its suitability for environmental and industrial applications, particularly in areas focusing on greenhouse gas capture and air purification, thereby inspiring further research and development in this field.
Selective reduction of CO2 to CO over alumina-supported catalysts of group 5 transition metal carbides
(Elsevier B.V., 2024-11-25) Pajares, Arturo; Ramírez de la Piscina, Pilar; Homs Martí, Narcís
We show the applicability of a preparation method, previously reported for obtaining tailored bulk VCx catalysts, for alumina-supported G5TMCs. The characteristics of the G5TMCs/Al2O3 catalysts and their behaviour in the selective reduction of CO2 to CO through the RWGS reaction is reported. VCx/Al2O3 catalysts were active, stable and highly selective; meanwhile NbC/Al2O3 and TaC/Al2O3 were not active. VCx/Al2O3 catalysts exhibited selectivity to CO over 99.5 % at temperature above 773 K. The characteristics of alumina-supported vanadium carbide particles depended on the vanadium precursor and on the atmosphere used during the catalyst preparation. XPS characterization of VCx/Al2O3 catalysts revealed the presence of carbide species on surface before and after RWGS reaction. The catalytic behaviour of VCx/Al2O3 is analysed in the light of their characteristics and compared with bulk VCx counterparts. The most performant catalyst, VC(Pr)/Al2O3, was stable over 4 days at 723 K, with ∼100 % selectivity to CO and CO2 conversion of ∼11 %.
Vertical graphene nanowalls supported hybrid W2C/WOxcomposite material as an efficient non-noble metal electrocatalystfor hydrogen evolution
(Elsevier, 2024-05-17) Rodriguez Miguel, Shahadev; Ma, Y.; Farid, Ghulam; Amade Rovira, Roger; Ospina, Rogelio; Andújar Bella, José Luis; Bertrán Serra, Enric; Chaitoglou, Stefanos
Research for the development of noble metal-free electrodes for hydrogen evolution has blossomed in recent years. Transition metal carbides compounds, such as W2C, have been considered as a promising alternative to replace Pt-family metals as electrocatalysts towards hydrogen evolution reaction (HER). Moreover, hybridization of TMCs with graphene nanostructures has emerged as a reliable strategy for the preparation of compounds with high surface to volume ratio and abundant active sites. The present study focuses in the preparation of tungsten carbide/oxide compounds deposited in a three-dimensional vertical graphene nanowalls (VGNW) substrate via chemical vapor deposition, magnetron sputtering and thermal annealing processes. Structural and chemical characterization reveals the partial carburization and oxidation of the W film sputtered on the VGNWs, due to C and O migration from VGNWs towards W during the high temperature annealing process. Electrochemical characterization shows the enhanced performance of the nanostructured hybrid W2C/WOx on VGNW compound towards HER, when compared with planar W2C/WOx films. The W2C/WOx nanoparticles on VGNWs require an overpotential of -252 mV for the generation of 10 mA cm-2. Chronoamperometry tests in high overpotentials reveal the compounds stability while sustaining high currents, in the order of hundreds of mA. Postchronoamperometry test XPS characterization unveils the formation of a W hydroxide layer which favours hydrogen evolution in acidic electrolytes. We aspire that the presented insights can be valuable for those working on the preparation of hybrid electrodes for electrochemical processes.
Halogen-Bonded Cocrystals for Tunable Phosphorescence Emission of Pt Complexes
(American Chemical Society, 2023-05-23) García del Amo, Mar Inés; Burguera, Sergi; Lázaro Palacios, Ariadna; Pinto Martínez, Andrea; Ward, Jas S.; Rissanen, Kari; Rodríguez Raurell, Laura; Frontera, Antonio
Noncovalent interactions, such as halogen bonding (HaB) and π-stacking, play a pivotal role in directing supramolecular assemblies and tuning photophysical properties. Herein, we report the synthesis, X-ray structural characterization, and photophysical properties of cocrystals and host:guest adducts formed by iodopentafluorobenzene (G) with three distinct Pt(II) complexes (1−3). The cocrystals exhibit a combination of short I···Pt halogen bonds and π-hole···Pt interactions in the solid state, highlighting the dual role of the Pt(II) center as a halogen bond acceptor and a π-stacking participant. Interestingly, an enhancement in emission intensity is observed for complexes 1·G and 2·G upon mixing of 1 or 2 with G in a chloroform solution, attributed to synergistic σ-hole···[dz2-PtII] interactions that reduce the flexibility of the square-planar complex and the double heavy atom effect. These results emphasize the potential of host:guest interactions as a strategy for enhancing luminescence efficiency and open new avenues for designing functional materials for sensing and optoelectronic applications.
Engineered SnO 2/BiOI fibers via electrospinning for robust visible-light/peroxymonosulfate -driven multipollutant mineralization
(Elsevier B.V., 2026-03-01) Huidobro, Laura; Allés, Miquel; Abid, Mahmoud; Bechelany, Mikhael; Sousa Romero, Carmen; Gómez, Elvira; Serrà i Ramos, Albert
Engineered photocatalysts capable of operating under visible light and realistic water matrices are needed to address emerging pharmaceutical contaminants. Here, we fabricate SnO2/BiOI fibrous heterostructures by electrospinning SnO2 nanofibers decorated with solvothermally synthesized BiOI followed by calcination. The electrospun fibers provide a mechanically robust, high-surface-area scaffold, while BiOI incorporation enhances visible-light absorption and creates SnO2/BiOI heterointerfaces. Textural, optical, and spectroscopic analyses reveal progressive surface decoration, increased surface area, and defect-rich Bi environments as BiOI loading increases. Using tetracycline (TC) as a model contaminant at neutral pH, SnO2/BiOI composites markedly outperform pristine SnO2 under visible light and/or peroxymonosulfate (PMS), with an optimal BiOI content (SBO2) under single-stimulus conditions and near-complete TC mineralization for the highest loading (SBO3) in the PMS + visible-light system. Radical scavenging indicates that SO4•− and •OH are the dominant reactive species, with O2•−, h+ and e− playing secondary roles. A multipollutant mixture (TC, sulfamethoxazole, levofloxacin, lansoprazole) is mineralized by >80% in both Milli-Q and tap water, and SBO3 retains high activity over nine cycles with Bi and I leaching below 0.05% after 48 h. Density functional theory calculations, combined with XPS, support an S-scheme SnO2/BiOI heterojunction, enabling spatial separation of strongly reducing electrons in BiOI and oxidizing holes in SnO2. Although high PMS loadings can partially mask intrinsic catalyst differences, these results outline a practical design platform for heterogeneous (slurry), visible-responsive, PMS-assisted photocatalysts for pharmaceutical-laden effluents.
Curvature induces and enhances transport of spinning colloids through narrow channels
(Royal Society of Chemistry, 2024-09-09) Cereceda López, Eric; Corato, Marco de; Pagonabarraga Mora, Ignacio; Meng, Fanlong; Tierno, Pietro; Ortiz-Ambriz, Antonio
The effect of curvature and how it induces and enhances the transport of colloidal particles driven through narrow channels represent an unexplored research avenue. Here we combine experiments and simulations to investigate the dynamics of magnetically driven colloidal particles confined through a narrow, circular channel. We use an external precessing magnetic field to induce a net torque and spin the particles at a defined angular velocity. Due to the spinning, the particle propulsion emerges from the different hydrodynamic coupling with the inner and outer walls and strongly depends on the curvature. The experimental findings are combined with finite element numerical simulations that predict a positive rotation translation coupling in the mobility matrix. Further, we explore the collective transport of many particles across the curved geometry, making an experimental realization of a driven single file system. With our finding, we elucidate the effect of curvature on the transport of microscopic particles which could be important to understand the complex, yet rich, dynamics of particle systems driven through curved microfluidic channels.
Depth-sensitive instrument for Mueller matrix imaging measurements
(Elsevier B.V., 2025-11-24) Pardo, Iago; Kuntman, Ertan; Ossikovski, Razvigor; Pascual Miralles, Esther; Arteaga Barriel, Oriol
We present an optical imaging approach that combines Spatial Frequency Domain Imaging (SFDI) and MuellerMatrix Imaging (MMI) to enable depth-resolved characterization of polarization properties in turbid media. Bysimultaneously exploiting the spatial selectivity of SFDI and the sensitivity of Mueller polarimetry to microstructuralanisotropy, our method provides complementary contrast mechanisms that reflect both the layered structureand polarization-dependent behaviour of complex samples. Spatially modulated illumination at multiple frequenciesis used to control the sampling depth, while full Mueller matrix measurements are performed at eachfrequency to capture the evolution of polarization as a function of depth. Experimental results in phantoms andbiological tissue demonstrate the potential of this dual-mode technique to distinguish subsurface polarizationfeatures that would otherwise remain obscured in conventional imaging. This integrated approach opens new possibilitiesfor applications requiring non-invasive, depth-sensitive analysis of anisotropic or scattering structures,such as biomedical diagnostics or material characterization.
Revolutionizing energy storage: Silicon nanowires (SiNWs) crafted throughmetal-assisted chemical etching
(King Saud University, 2024-01-17) Farid, Ghulam; Amade Rovira, Roger; Ma, Y.; Chaitoglou, Stefanos; Ospina, Rogelio; Bertrán Serra, Enric
In the world of advanced energy conversion and storage, silicon nanostructures have garnered immense interestof scientists and innovators alike with their unique structural, electrical, optical and electrochemical properties,setting the stage for a brighter, more sustainable future. Amidst the array of top-down methods, one methodstands out as an approach-change: Metal-assisted chemical etching (MacEtch). It is highlighted for its cost-effectiveness, simplicity, versatility and scalability, making it a crucial point in the world of micro/nano Sistructure fabrication. Recent breakthroughs have propelled MacEtch into the limelight, making it the go-totechnique for crafting micro/nano structures with exceptional electrochemical attributes. These structures aretailor-made for energy storage applications, from lithium-ion batteries (LIBs) to supercapacitors. Join us in thiscaptivating feature article as we unveil the mechanism underlying the MacEtch’s silicon transformation. Explorethe latest and old strides achieved in the field of Silicon nanowires (SiNWs) generated through MacEtch,particularly in the context of their electrochemical properties for energy storage applications.
Engineered π⋯π interactions favour supramolecular dimers $\mathrm{X@[FeL_{3}]_{2}(X = Cl, Br, I)}$: solid state and solution structure
(Royal Society of Chemistry, 2024-05-28) Risa, Arnau; Barrios Moreno, Leoní Alejandra; Diego, Rosa; Roubeau, Olivier; Aleshin, Dmitry Y.; Nelyubina, Yulia; Novikov, Valentin; Teat, Simon J.; Ribas Ariño, Jordi; Aromí Bedmar, Guillem
Ditopic bis-pyrazolylpyridine ligands usually react with divalent metal ions ($\mathrm{M^{2+}}$) to produce dinuclear triple- stranded helicates $\mathrm{[M_{2}L_{3}]^{4+}}$ or, via $\mathrm{\pi\cdots\pi}$ interactions, dimers of monoatomic complexes $\mathrm{([ML_{3}]_{2})^{4+}}$. The introduction of an additional benzene ring at each end of ligand L increases the number of aromatic contacts within the supramolecular aggregate by 40%, driving the self-recognition process in an irreversible manner. Consequently, the mixing of new bis-pyrazolylquinoline L2 with $\mathrm{FeX_{2}}$ salts leads to crystallization of the tripartite high-spin assemblies $\mathrm{(X@[Fe(L2)_{3}]_{2})^{3+}(X = Cl, Br or I)}$. The aggregates exhibit exceptional stability, as confirmed by a combination of paramagnetic $\mathrm{^{1}H}$ NMR techniques, demonstrating their persistence in solution. Our investigations further reveal that the guests$\mathrm{Br^{-}}$ and $\mathrm{I^{-}}$ are retained inside the associate in solution but $\mathrm{Cl^{-}}$ is immediately released, resulting in the formation of the empty supramolecular dimer $\mathrm{([Fe(L2)_{3}]_{2})^{4+}}$
Family of Quasi-Isotropic $Mn^{II}$ and ${Mn_2}^{II}$ Complexes Exhibiting Slow Relaxation of the Magnetization
(American Chemical Society, 2024-10-16) Pilichos, Evangelos; Font Bardia, Ma. Mercedes; Aullón López, Gabriel; Mayans Ayats, Júlia; Escuer Fité, Albert
Slow relaxation of magnetization has been studied for a family of mononuclear MnII complexes and one ferromagnetic dinuclear system, all of them presenting very weak anisotropy. Complexes with formula $[\{NiL1Mn-(H_{2}O)_{2}(MeOH)\}\{NiL1\}_{2}](ClO_{4})_{2}$ (1), [Mn{NiL1}2](ClO4)2 (2), $[Mn\{NiL2\}_{2}](ClO_{4})_{2}(RR-L2^{2-}, 3RR, SS-L2^{2-}, 3SS)$, $[Mn\{NiL3\}_{2}](ClO_{4})_{2}(RR-L3^{2-}, 4RR, SS-L3^{2-}, 4SS)$ and $(\mu_{1,1}-N_{3})_{2}[Ni_{2}Mn_{2}(L1)_{2}(N_{3})_{2}]$ (5) are derived from compart- mental Schiff bases, in which the NiII environment is square planar and thus diamagnetic. All of the systems have been structurally and magnetically characterized. Zero field splitting (D) values for the MnII cations have been obtained from EPR spectroscopy and NEVPT2 calculations. The slow relaxation of the magnetization for 1−5 has been studied by means of ac magnetometry and rationalized on the basis of their low, but not zero, anisotropy, providing the first example of a polynuclear MnII complex, with S = 5 ground state, exhibiting slow relaxation.
Surface modification of hierarchical hydroxyapatite fabricated via hydrothermal method
(Elsevier B.V., 2024-06-01) Mohandes, Fatemeh; Gómez, Elvira; Serrà i Ramos, Albert
Surface modification, encompassing both chemical and physical features, plays a crucial role in fulfilling the requirements of biomaterial applications and also improves their performance. Due to that, this study focuses on the optimization of morphology and functionalization of hydroxyapatite (HAP). For this purpose, hydrothermal growth of HAP on (fluorine tin oxide) FTO is carried out in the presence of calcium and phosphate precursors with Ca/P molar ratio of 1.67:1 in the solution. Trisodium nitrilotriacetic acid (NTA) is used as a chelating additive for the first time during hydrothermal process at temperature between 120 and 180 °C for 16–24 h. Further studies on the effect of NTA concentration on HAP formation indicate that hierarchical structures are formed in the presence of NTA with NTA/Ca molar ratio of 1:1 at temperature between 150 and 180 °C for 24 h, improving crystallinity as temperature increasing. To facilitate the functionalization of HAP, the layer deposited at 180 °C with NTA/Ca molar ratio of 1:1 is peeled using two different reagents, Fluoromount™ and polyvinyl alcohol (PVA). The HAP peeled with PVA shows no relevant morphological changes in SEM images, indicating a successful peeling process using PVA. After that, the HAP powders are functionalized with alendronate (AL) molecules and studied using ATR-FTIR, XPS and BET techniques. Chemical shift of PO43− vibrations and appearance of the new peaks assigned to the –NH2 group demonstrate successful AL-functionalization. The AL-HAP hierarchical structures fabricated with the aid of NTA can be introduced as multifunctional biomaterials for future bio-applications.
Trusting the forces of our cell lines
(Elsevier, 2024-09-01) Moro López, Marina; Farré Ventura, Ramon; Otero Diaz, Jorge; Sunyer Borrell, Raimon
Cells isolated from their native tissues and cultured in vitro face different selection pressures than those cultured in vivo. These pressures induce a profound transformation that reshapes the cell, alters its genome, and transforms the way it senses and generates forces. In this perspective, we focus on the evidence that cells cultured on conventional polystyrene substrates display a fundamentally different mechanobiology than their in vivo counterparts. We explore the role of adhesion reinforcement in this transformation and to what extent it is reversible. We argue that this mechanoadaptation is often understood as a mechanical memory. We propose some strategies to mitigate the effects of on-plastic culture on mechanobiology, such as organoid-inspired protocols or mechanical priming. While isolating cells from their native tissues and culturing them on artificial substrates has revolutionized biomedical research, it has also transformed cellular forces. Only by understanding and controlling them, we can improve their truthfulness and validity.
Confinement-driven emergence of hyperuniform fluids
(American Physical Society, 2025-12-15) Leoni, Fabio; Franzese, Giancarlo; Oguz, Erdal C.; Martelli, Fausto
Controlling emergent structural order in spatially constrained systems is a fundamental challenge. Using large-scale simulations of a model fluid at equilibrium conditions, we show that geometric confinement alone can stabilize fluid and hyperuniform labyrinthine phases. Moreover, confinement can induce self-assembly into distinct regimes—ranging from nonhyperuniform to antihyperuniform configurations—providing a robust mechanism for tuning spatial order. Our results identify confinement as a minimal design principle for engineering systems with target structural properties, including (anti)hyperuniformity, without relying on genetic or chemical specificity, and with broad applications in multiple disciplines and technologies.
Efficient parallel algorithms for free-energy calculation of millions of water molecules in the fluid phases
(Frontiers Media, 2025-09-16) Coronas, Luis Enrique; Vilanova, Oriol; Franzese, Giancarlo
Simulating water droplets made up of millions of molecules and on timescales as needed in biological and technological applications is challenging due to the difficulty of balancing accuracy with computational capabilities. Most detailed descriptions, such as ab initio, polarizable, or rigid models, are typically constrained to a few hundred (for ab initio) or thousands of molecules (for rigid models). Recent machine learning approaches allow for the simulation of up to 4 million molecules with ab initio accuracy but only for tens of nanoseconds, even if parallelized across hundreds of GPUs. In contrast, coarse-grained models permit simulations on a larger scale but at the expense of accuracy or transferability. Here, we consider the CVF molecular model of fluid water, which bridges the gap between accuracy and efficiency for free-energy and thermodynamic quantities due to i) a detailed calculation of the hydrogen bond contributions at the molecular level, including cooperative effects, and ii) coarse-graining of the translational and rotational degrees of freedom of the molecules. The CVF model can reproduce the experimental equation of state and fluctuations of fluid water across a temperature range of 60$\,^{\circ}$ around ambient temperature and from 0 to 50 MPa. In this work, we describe efficient parallel Monte Carlo algorithms executed on GPUs using CUDA, tailored explicitly for the CVF model. We benchmark accessible sizes of 17 million molecules with the Metropolis and 2 million with the Swendsen-Wang Monte Carlo algorithm.

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