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Acid Mine Drainage (AMD) is a significant environmental problem in the mining industry due to its high concentration of hazardous metals and metalloids, sulfate compounds, and low pH levels. Despite the attention that iron oxide magnetic nanoparticles (MNP) have received for AMD remediation, there is still a lack of understanding of the physicochemical mechanisms behind their non-specific adsorption, particularly in distinct variations of AMD, such as Cu-rich AMD. In this study, we synthesized, characterized, and applied MNP to the two-step treatment of Cu-rich AMD. The chemical and physical properties of the MNP and magnetically separated sludges after AMD treatment are characterized. Additionally, the chemical species adsorbed onto the MNP, the oxidation state of the resultant sludge after Cu-rich AMD treatment, and the short-range ordering of metal contaminant species on the surface of the MNP are identified. Finally, first-principles calculations using Density Functional Theory were conducted to understand how different Cu ion species adsorb to the MNP surface depending on the pH of the Cu-rich AMD. The bonding between MNP and Cu species occurs primarily through metal cation-oxygen bonds on the surface of MNP, and this bonding is influenced by the pH of the solution. A combination of experimental and theoretical approaches was the key to arrive at this conclusion. This information can aid in the comprehension of how metal contaminants adhere to the surfaces of MNP and in the precise engineering of these nanoparticles.

Nanoparticle-mediated thermal treatments have demonstrated high efficacy and versatility as a local anticancer strategy beyond traditional global hyperthermia. Nanoparticles act as heating generators that can trigger therapeutic responses at both the cell and tissue level. In some cases, treatment happens in the absence of a global temperature rise, damaging the tumor cells even more selectively than other nanotherapeutic strategies. The precise determination of the local temperature in the vicinity of such nanoheaters then stands at the heart of thermal approaches to better adjust the therapeutic thermal onset and reduce potential toxicity-related aspects. Herein, we describe an experimental procedure by X-ray absorption spectroscopy, which directly and accurately infers the local temperature of gold-based nanoparticles, single and hybrid nanocrystals, upon laser photoexcitation, revealing significant nanothermal gradients. Such nanothermometric methodology based on the temperature-dependency of atomic parameters of nanoparticles can be extended to any nanosystem upon remote hyperthermal conditions.

Silicon carbide (SiC) attracts a lot of attention for several useful applications such as semiconductor devices and structural materials under severe conditions because of its outstanding electronic properties as well as high physical and chemical stabilities. However, it is difficult to fabricate meso- and macropores in SiC because of its inertness. In this study, macroporous SiC with a pore size of several micrometers was fabricated by anodizing SiC with point defects which were formed by high-energy Si(II) ion irradiation. This is because irradiated SiC has an electrochemical activity caused by the combination of irradiation-induced defects and dopants. This result suggests that the control of lattice defects is a promising strategy for the surface processing of SiC. We propose that this study gives a new prospect of the electrochemical activation of SiC and opens various fields of its application.

The aim of this work is to clarify how in-plane magnetic anisotropy and magnetoelasticity depend on the thickness of Ga-rich FeGa layers. Samples with an Fe72Ga28composition were grown by sputtering in the ballistic regime in oblique incidence. Although for these growth conditions uniaxial magnetic anisotropy could be expected, in-plane anisotropy is only present when the sample thickness is above 100 nm. By means of differential X-ray absorption spectroscopy, we have determined the influence of both Ga pairs and tetragonal cell distortion on the evolution of the magnetic anisotropy with the increase of FeGa thickness. On the other hand, we have used the cantilever beam technique with capacitive detection to also determine the evolution of the magnetoelastic parameters with the thickness increase. In this case, experimental results can be understood considering the grain distribution. Therefore, the different physical origins for anisotropy and magnetoelasticity open up the possibility to independently tune these two characteristics in Ga-rich FeGa films.

We have investigated the influence of the growth power on the structural properties of Fe100–xGax(xca. 29) films sputtered in the ballistic regime in the oblique incidence. By means of different structural characterizations, mainly X-ray diffraction and X-ray absorption spectroscopy, we have reached a deeper understanding about the influence of the local and medium range order on the magnetic behavior of Ga-rich FeGa thin films. On the one hand, the increase of the growth power reduces the crystallite size (medium order) that promotes the decrease of the coercive field of the layers. On the other hand, the growth power also determines the local order as it controls the formation of the A2, B2, and D03structural phases. The increase of the uniaxial in-plane magnetic anisotropy with growth power has been correlated with the enhancement of both Ga pairs and a tetragonal distortion. The results presented in this work give more evidence about the magnetic anisotropy sources in Ga-rich FeGa alloys, and therefore, it helps to understand how to achieve a better control of the magnetic properties in this family of alloys.

Temperature plays a critical role in regulating body mechanisms and indicating inflammatory processes. Local temperature increments above 42 °C are shown to kill cancer cells in tumorous tissue, leading to the development of nanoparticle‐mediated thermo‐therapeutic strategies for fighting oncological diseases. Remarkably, these therapeutic effects can occur without macroscopic temperature rise, suggesting localized nanoparticle heating, and minimizing side effects on healthy tissues. Nanothermometry has received considerable attention as a means of developing nanothermosensing approaches to monitor the temperature at the core of nanoparticle atoms inside cells. In this study, a label‐free, direct, and universal nanoscale thermometry is proposed to monitor the thermal processes of nanoparticles under photoexcitation in the tumor environment. Gold‐iron oxide nanohybrids are utilized as multifunctional photothermal agents internalized in a 3D tumor model of glioblastoma that mimics the in vivo scenario. The local temperature under near‐infrared photo‐excitation is monitored by X‐ray absorption spectroscopy (XAS) at the Au L3‐edge (11 919 eV) to obtain their temperature in cells, deepening the knowledge of nanothermal tumor treatments. This nanothermometric approach demonstrates its potential in detecting high nanothermal changes in tumor‐mimicking tissues. It offers a notable advantage by enabling thermal sensing of any element, effectively transforming any material into a nanothermometer within biological environments. X‐ray nanothermometry enables monitoring of nanoparticle temperature in cells, introducing a label‐free nanoscale thermometry for tracking thermal processes in tumors. Photoexcited gold‐iron oxide nanohybrids in a 3D glioblastoma model are examined using X‐ray absorption spectroscopy, enhancing understanding of nanothermal treatments. The approach detects significant nanothermal changes, enabling thermal sensing of any element in biological environments and material transformation into nanothermometers.

Embolization X‐ray nanothermometry enables monitoring of nanoparticle temperature in cells, introducing a label‐free nanoscale thermometry for tracking thermal processes in tumors. In article 2301863by Álvaro Muñoz‐Noval, Ana Espinosa, and co‐workers, photoexcited gold‐iron oxide nanohybrids in a 3D glioblastoma model are examined using X‐ray absorption spectroscopy, enhancing understanding of nanothermal treatments. The approach detects significant nanothermal changes, enabling thermal sensing of any element in biological environments and material transformation into nanothermometers.

Nowadays, iron oxide-based nanostructures are key materials in many technological areas. Their physical and chemical properties can be tailored by tuning the morphology. In particular, the possibility of increasing the specific surface area has turned iron oxide nanowires (NWs) into promising functional materials in many applications. Among the different possible iron oxide NWs that can be fabricated, maghemite/hematite iron oxide core/shell structures have particular importance since they combine the magnetism of the inner maghemite core with the interesting properties of hematite in different technological fields ranging from green energy to biomedical applications. However, the study of these iron oxide structures is normally difficult due to the structural and chemical similarities between both iron oxide polymorphs. In this work, we propose a route for the synthesis of maghemite/hematite NWs based on the thermal oxidation of previously electrodeposited iron NWs. A detailed spectroscopic analysis based on Raman, Mössbauer, and X-ray absorption shows that the ratio of both oxides can be controlled during fabrication. Transmission electron microscopy has been used to check the core/shell structure of the NWs. The biocompatibility and capability of internalization of these NWs have also been proven to show the potential of these NWs in biomedical applications.

Recent studies have revealed that electrochemistry at the nanometer scale is profoundly different from its conventional framework. We reported that the combination of a hydrophobic nanoporous electrode and low-charge-density metal ions resulted in a drastic acceleration in the electrodeposition reaction. In the present study, we analyzed Zn embedded in nanoporous silicon by X-ray absorption fine structure spectroscopy. As a precursor to Zn electrodeposition, Zn(II) chelate was used under different pH conditions. The spectroscopy results clearly suggest that the accumulation of Zn(II) chelate occurred at pH conditions where the Zn(II) chelate had zero charge. The accumulation resulted in the promotion of Zn electrodeposition within confined nanopores. Based on this spectroscopic investigation, we propose a model for the accelerated electrodeposition of Zn in confined nanopores.

The symmetry of the room-temperature (RT) structure of title compounds La2–xSrxCoTiO6−δchanges with x, from P21/n(0 ≤ x≤ 0.2) to Pnma(0.3 ≤ x≤ 0.5) and to R3̅c(0.6 ≤ x≤ 1). For x= 1 the three pseudocubic cell parameters become very close suggesting a transition to a cubic structure for higher Sr contents. Similar phase transitions were expected to occur on heating, paralleling the effect of internal pressure induced by substitution of La3+by Sr2+. However, only some of these aforementioned transitions have been thermally induced. The symmetry-adapted modes formalism is used in the structural refinements and fitting of neutron diffraction data recorded from RT to 1273 K. Thus, for x= 1, the out-of-phase tilting of the BO6octahedra vanishes progressively on heating, and a cubic structure with Pm3̅msymmetry is found at 1073 K. For lower Sr contents this transition is predicted to occur far above the temperature limit of common experimental setups. The analysis of the evolution of the perovskite tolerance factor, t-factor, with both Sr content and temperature indicates that temperature has a limited ability to release structural stress and thus to enable transitions to more symmetric phases. This is particularly true when compared to the effect of internal pressure induced by substitution of La by Sr. The existence of phase transitions in materials for solid oxide fuel cells that are usually exposed to heating–cooling cycles may have a detrimental effect. This work suggests strategies to stabilize the high-symmetry high-temperature phase of perovskite oxides through internal-pressure chemically induced.

We present structural, electronic, and morphological characterization of thin (7.5 nm, 9 unit cells) and ultrathin (1.7 nm, 2 unit cells) Fe3O4layers grown on SrTiO3(001) by oxygen assisted molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) methods. The analysis show single-phase single oriented (001) layers that grow forming a coincidence lattice of the order 13. Such an incommensurate growth is present for all the layers, independent of the evaporation method and layer thickness. The magnetite layers, which are strain-free, provide a sharp interface with the substrate. The films grown by the MBE method present negligible interaction with the substrate and smooth surfaces. The films grown by the PLD evaporation method present an expansion of the last atomic layer of the substrate and rough layer surface. However, the obtained structural domain size of 10 nm is identical for the layers grown by both evaporation techniques corresponding to the size of the coincidence lattice. We determine that the magnetic and transport properties inherent to the Fe3O4/STO heterostructure are not related to the lattice strain but to the formation of antiphase boundary defects.

Introduction:The particular properties of nanostructured porous silicon (nanoPS) make it an attractive material for controlled and localized release of therapeutics within the body, aiming at increased efficacy and reduced risks of potential side effects. Since this is a rapidly evolving field as a consequence of the number of research groups involved, a critical review of the state of the art is necessary.Areas covered:In this work, the most promising and successful applications of nanoPS in the field of drug delivery are reviewed and discussed. Two key issues such as drug loading and release are also analyzed in detail. The development of multifunctional (hybrid) systems, aiming at imparting additional functionalities to the nanoPS particles such as luminescence, magnetic response and/or plasmonic effects (allowing simultaneous tracking and guiding), is also examined.Expert opinion:Nanostructured materials based on silicon are promising platforms for pharmaceutical applications given their ability to degrade and low toxicity. However, a very limited number of clinical applications have been demonstrated so far.

Cu–porous silicon (Cu–PS) composite materials consisting of nanosized Cu clusters preferentially grown on the surface of PS were fabricated by photoassisted deposition of Cu nanoparticles onto PS. Structural and chemical characterization of the Cu particles grown in the PS matrix has been carried out by synchrotron X-ray absorption spectroscopy, from which different reaction stages have been identified within the photoassisted reaction. In particular, it was found that the reduction of Cu occurs in three main phases: (a) Cu nucleates homogeneously in a few seconds over the surface of PS by a coupled red-ox reaction; (b) clusters grow by new reduced ions, which tend to oxidize the previously deposited Cu atoms making increasingly heterogeneous Cu clusters; and (c) a competitive process between nucleation of new clusters and cluster coalescence gives rise to a bulklike Cu thin film. It was determined that the structures formed in the first two phases display surface plasmon resonance, with band intensity and broadening consistent with the increasing heterogeneity of the clusters. The growth kinetics has been fitted to a Langmuir–Hill model. Following these results, a reaction model has been proposed to explain the mechanisms involved in the first stages of Cu clustering.

In this work nanostructured porous silicon (nanoPS) was used for the fabrication of surface micropatterns aiming at controlling cell adhesion and migration. In particular, surface patterns of nanoPS and Si were engineered by high-energy ion-beam irradiation and subsequent anodization. It was found that human skeletal progenitor cells are sensitive to oneand two-dimensional patterns and that focal adhesion is inhibited on nanoPS areas. In spite of this anti-fouling characteristics, studies on patterns with reduced Si areas show that cells conform to nanoPS pathways favoring migration through cell protrusion, body translocation and tail retraction from two parallel Si traction rails. Moreover, migration can be blocked and cells tend to arrange when grid patterns with the appropriate dimensions are fabricated. The experimental results confirm that progenitor cells are able to exploit nanoPS anti-fouling designs by adapting to it for migration purposes.

Reinforcement corrosion leads into several damages which influence the structural load-bearing capacity, among which can be mentioned the cracking of concrete cover. This work study formulations to estimate the crack width of structural elements from the data of corrosion rate measured in two structural elements, made in 1990, with chlorides added in the concrete mix. These elements, one T beam and one column, were exposed at the atmosphere of Madrid, Spain. Two expressions have been fitted to the results: w = k Px / (c/f) and w = k Px / Ro, where w is a crack width in the time, k is a proportional factor, Px is the corrosion penetration in the time, c/f is the concrete cover/diameter relation and Ro is the original radius of the bar. The first expression has resulted the most adequate.

This paper shows how the corrosion and mechanical actions can be taken into account in a simple model for the assessment of structural elements. This work is framed in the Project Benchmark des Poutres de La Rance in which several partners have participated. The Project tried to characterize the degradation of reinforced and prestressed concrete structures after an aging in marine atmosphere with non-destructive methods and to evaluate different existing models for the structural assessment. For this aim a 4-point bending test was performed on six prestressed concrete beams. The model gives a reasonable approach for the assessment of structural elements. Similar rules can be adopted for other failure modes. It is important to notice the need of reliable input data for the assessment and also the need of integration of deterioration processes in design.