Introduction: A key concern for the risk assessment of metallic engineered nanomaterials in the terrestrial environment is the degree to which particle size and functional coatings may alter particle dissolution transformations and subsequent toxicity and bioaccumulation effects. To address this question, we integrated nanoparticle characterization, surface transformation analyses, Cu2+ activity measurements, and chronic toxicity within a single standardized soil study to determine whether engineered particle properties remain predictive of biological responses following environmental transformation. Materials and methods: This study investigated the effects of nanoscale copper (II) oxide (CuO) particle size (10 and 25–55 nm, nominal) and coatings (polyvinylpyrrolidone (PVP), steric acid (SA), uncoated) on Cu bioaccumulation and toxicity (survival, reproduction) to the earthworm Eisenia andrei in a sandy loam soil, using the standardized Environment and Climate Change Canada test method STB 1/RM/43. Transformations to particle surfaces and coatings were analyzed by thermogravimetric analysis, while Cu2+ activity in soil extracts, determined by a Cu2+ ion-selective electrode, was used to assess the degree of particle dissolution over time. Results: The EC50 estimates did not indicate a consistent size effect on toxicity and only indicated a coating effect for the 10 nm substances, for which uncoated CuO showed the greatest toxicity to reproduction with an EC50 (lower–upper 95% confidence intervals) of 60 (43–85) μg Cu g−1 soil, compared to the 10 nm PVP- and SA-coated materials which showed the least toxicity of all the materials tested, with EC50s of 135 (86–211) and 258 (161–413) μg g−1, respectively. The 10 nm uncoated CuO also showed the greatest Cu bioaccumulation (BSAF = 1.9) compared to all other substances for which BSAFs ranged from 0.48 to 0.75. Particle surface transformations in soil porewater revealed that the uncoated materials accumulated organic matter (OM) on their surfaces (up to 3.9% mass loss) and showed the largest pools of Cu2+ activity in soils after 24 h. In contrast, the SA coating prevented OM deposition on particle surfaces and showed 4- to 60-fold less Cu2+ activity in soil exposures. Conclusions: Although particle size and surface coating influenced the early transformation and dissolution behaviour of nCuO in soil, neither property produced consistent effects on earthworm response across treatments, and extractable Cu2+ activity was not a sufficient predictor of toxicity. The rapid surface transformations observed suggest that pristine particle characteristics may have limited predictive value as exposure progresses. Hazard assessment of partially soluble metallic nanomaterials may therefore benefit from descriptors that better reflect their environmentally transformed state and the combined contributions of particulate and dissolved toxicant forms.
Introduction: A study of correlation effects in graphene and twisted bilayer graphene is presented, using the extended-coupled-cluster method. Materials and methods: The extended coupled-cluster approach contains both self-consistent mean-field and beyond mean-field contributions, and can describe phase transitions in such strongly correlated systems, without further inputs or assumptions. Detailed expressions and a suitable implementation for the method are developed. Combining modern tensor contraction techniques with singular value decomposition, the correlation effects are successfully described in a qualitative manner, including contributions from the short-range and long-range parts of the Coulomb interaction. Results: We demonstrate validity of the method for use in grahene. Within the approximations used, the superconducting gap shows a possible maximum near a twist angle of θ c ≈ 1.00 ° . A rough Bardeen-Cooper-Schrieffer (BCS) scale estimate gives T c BCS ≈ 0.5 K, broadly consistent in order of magnitude with experimental reports. Conclusions: These results constitute a qualitative, proof-of-principle indication of a correlation-driven pairing tendency in twisted bilayer graphene; a more quantitative identification of the superconducting mechanism would require substantial further computational resources.
Introduction: Noncoplanar magnetic textures such as skyrmion and bimeron crystal (BMX) phases have attracted considerable interest in frustrated magnetic systems. However, the effect of lattice distortion on the competition among multiple-Q magnetic instabilities remains unclear.Materials and methods: We investigate a distorted triangular-lattice spin model with easy-plane single-ion anisotropy under an external magnetic field by means of simulated annealing calculations. The magnetic phases are characterized through magnetization, scalar spin chirality, real-space spin textures, and spin structure factors.Results: We find that lattice distortion qualitatively reconstructs the competition among symmetry-related ordering wave vectors and modifies the stability of multiple-Q magnetic phases. Near the isotropic limit, an intermediate-field BMX phase with finite scalar spin chirality is stabilized. Increasing distortion destabilizes the BMX phase and induces transitions into distinct coplanar and noncoplanar triple-Q phases. The distortion also lifts the degeneracy among the ordering wave vectors and selectively enhances specific modulation channels.Conclusions: Our results demonstrate that lattice distortion acts as an effective control parameter for tuning field-induced multiple-Q instabilities in centrosymmetric frustrated magnets. The present study clarifies how distortion reorganizes the competition among ordering wave vectors beyond the stabilization mechanism of individual topological spin textures.
Introduction: Multiple-stimuli-responsive materials which respond to multiple stimuli such as temperature, vapor, and mechanical pressure, are expected to have applications in next-generation nanoelectronics such as logic gates. Solid-state luminescent dyes, in particular, are expected to be put into practical use, but it was extremely difficult to achieve both luminescence and stimulus responsiveness with conventional dyes. To overcome this challenge, we newly conjured solid-state exciplex emission to o-carborane-modified dyes and constructed molecular logic gates.Materials and methods: Solid exciplex formation was attempted using ball mills with N,N-diethylaniline-modified o-carborane and pyrene derivatives as donor and acceptor units, respectively. The luminescent species of the mixed solid-state luminescent material were assigned using various spectroscopic methods. Two types of inputs, acid and temperature, were used for the molecular logic gate, and the emission wavelength or emission intensity corresponding to each luminescent species was used as outputs.Results: First, we observed exciplex formation from the solid mixture with N,N-diethylaniline-modified o-carborane and pyrene. From the optical measurements, we discovered that treatment of this solid mixture with acid vapor simultaneously quenched exciplex emission and restored the locally excited emission from pyrene. We also found that the solid mixture containing two kinds of o-carborane derivatives, each modified with pyrene and N,N-diethylaniline, exhibited multiple-stimuli-responsive properties to temperature and acid. Finally, we achieved complex molecular logic gate in response to luminescence wavelength or intensity.Conclusions: Based on aryl-modified o-carborane systems, we were able to obtain exciplex emission from a solid sample originating from the donor-acceptor interaction. Furthermore, we were able to construct solid-state luminescent materials that can exhibit logic circuit responses.
Introduction: Layered double hydroxides (LDHs) are promising compounds whose properties can be tuned through compositional variation, including the preparation of multi-cation and high-entropy materials. In such complex systems, the band gap is a key parameter governing optical absorption, charge transport, and photocatalytic behavior, and its systematic investigation is therefore essential for understanding structure–property relationships.Materials and methods: In this work, the band gap energies of nine multi-cation and high-entropy LDHs samples, determined from diffuse reflectance spectra using the Kubelka–Munk approach, were evaluated.Results: The calculated band gap values indicate that the samples are wide-bandgap semiconductors with no clear monotonic dependence on either the number of cations or their ratios.Conclusions: This preliminary study suggests that, for the specific multi-cation and high-entropy LDHs investigated, cation identity may have a stronger influence on the apparent optical band gap than cation number or ratio.
This study explores the fabrication of nanoscale, fine-grained aluminosilicate thick films using dry aerosol deposition (DAD) and investigates how substrate hardness influences film evolution, morphology, and mechanical performance. Amorphous aluminosilicate powders were deposited at room temperature onto aluminum, stainless steel, and glass substrates, representing a wide hardness spectrum (1.5–6 GPa). Scanning electron microscopy (SEM), Atomic force microscopy (AFM), and nanoindentation analyses revealed that substrate hardness plays a role in particle anchoring, initial morphology, and roughness, and final film roughness and hardness. The deposited coatings achieved thicknesses of 5–11 μm with good adhesion. Tensile pull-off strength ranged from 18.5 to 25.3 MPa with predominantly cohesive failure, indicating strong interfacial adhesive bonding. Biaxial loading (scratch testing) of coatings on aluminum revealed average cohesive and adhesive failure loads of 4.4 and 9.0 N respectively. Films deposited on steel exhibited the highest hardness (5.9 GPa), highest tensile pull strength (25 MPa), and no evidence of adhesive failure even at the highest scratch load (25 N), suggesting an optimal energy transfer to particle fracture and particle embedding. These findings highlight the substrate’s role in the mechanical properties of DAD coatings, and demonstrate the viability of aluminosilicate as a low-cost, unrefined feedstock for protective DAD coatings.
Rare-earth (RE)-doped Y2O3 nanoparticles (NPs) have been extensively investigated due to their remarkable optical properties, particularly as scintillators. For applications as primary sensors in high-resolution X-ray detection systems or in other photonic uses such as panel displays, these materials must present controlled and homogeneous particle size distribution, be effectively dispersed within a suitable host matrix, and their optical response must be properly evaluated within the relevant excitation energy range. In this work, we present a comprehensive multi-analytical study, integrating synchrotron-based methods to characterize the structure, crystallite size, morphology, and band gap of Eu- and Tb-doped Y2O3 NPs; the thickness and homogeneity of polydimethylsiloxane (PDMS)-based composite films; the oxidation states and local symmetry of the dopants; and luminescent behavior of both Y2O3:RE powders and Y2O3:RE@PDMS composite films. Furthermore, their luminescence mechanisms under vacuum ultraviolet (VUV) and X-ray irradiation were systematically investigated. Advanced synchrotron X-ray microscopy was used to correlate the chemical composition with the optical performance of Y2O3:Tb@PDMS luminescent screens. The results demonstrate a simple and cost-effective PVA-assisted sol–gel synthesis route for producing Y2O3:RE nanopowders and highlight the potential of Y2O3:RE@PDMS composites as flexible, high-performance, and easily fabricated primary sensors for X-ray imaging or even for other photonic applications.
Water confined in low-dimensional materials exhibits structural and dynamical behaviors that diverge fundamentally from bulk liquid water. Nanoscale confinement reshapes the hydrogen-bond network, induces molecular ordering, and alters dielectric, vibrational, and transport properties through the interplay between geometry, surface chemistry, and electrostatics. This review presents a comparative synthesis of confined water in 0D–2D environments, from single-molecule encapsulation in molecular cages and single-file flow in carbon nanotubes to layered phases trapped between atomically flat van der Waals crystals. We outline how dimensionality and surface polarity dictate hydrogen-bond rearrangement, layering, and crystallization into low-dimensional ice polymorphs. Spectroscopically, Raman, infrared, terahertz, and nonlinear optical probes reveal distinct vibrational fingerprints reflecting modified hydrogen-bond strength, dipole alignment, and collective dynamics. In the transport regime, continuum hydrodynamics breaks down, giving rise to superlubric flow, anisotropic diffusion, and quantized single-file motion. Across these systems, confinement transforms water from a fluctuating three-dimensional liquid into a tunable, ordered medium bridging molecular and solid-state physics. By unifying results across structural, spectroscopic, and transport studies, this review provides a coherent physical framework for understanding confined water in low-dimensional materials and highlights its implications for nanofluidics, energy storage, and bio-inspired systems.
Reduced graphene oxide (RGO) forward osmosis (FO) membranes have emerged as promising candidates for efficient wastewater management and osmotic energy harvesting, due to their enhanced chemical stability and superior FO performance for low-energy waste brine treatments, such as volume reduction in oxidative chromium brine for cost-effective disposal. This study examines the oxidation resistance of RGO forward osmosis membranes against chromate Cr(VI). Our findings reveal that both the water flux and the reverse salt flux of RGO membranes are suppressed, accompanying an enhanced reverse flux selectivity after exposure to an acidic or neutral medium of Cr(VI) (pH 2.0–7.0). After exposure to a basic Cr(VI) medium of pH 10.0, an increase in reverse salt flux and a reduction in reverse flux selectivity are observed, which could be due to the synergistic effect of both pH and ionic solutes on the RGO membranes, not due to Cr(VI) oxidation. Remarkably, after the removal of chromate with a full rinse, the RGO membranes show a nearly complete recovery of their FO performance.
Water under nanoscale confinement exhibits structural, dynamical behaviors that differ profoundly from its bulk counterpart. Within angstrom-to-nanometer spaces, disrupted hydrogen bond networks, modified dielectric screening, and spatial ordering of water molecules give rise to unique hydration environments for ions. This review examines how the structural organization of confined water governs ion transport in nanochannels. We first discuss the emerging understanding of water structuring under confinement, highlighting the interplay between geometric restriction and interfacial chemistry. We then focus on the hydration structure of ions, including the suppression and deformation of hydration shells, the formation of layered solvation patterns, and their consequences on ionic mobility and selectivity. The discussion further extends to ion–ion interactions and collective transport phenomena that arise from reduced dielectric permittivity and electrostatic screening of confined water. Finally, we analyze how the hydrogen bond network topology and its dynamic fluctuations mediate proton and ion conduction in low-dimensional aqueous systems. Together, these insights reveal confined water as an active medium—rather than a passive solvent—that fundamentally shapes the physics of ion transport at the nanoscale, with implications for nanofluidics, energy conversion, and biomolecular interfaces.
Nanoconfined water—ubiquitous across both engineered nanoporous adsorbents and subsurface geological formations—plays a pivotal yet underexplored role in carbon capture and storage (CCS). This review systematically examines the physicochemical properties and functional implications of water confined within nanoporous environments, emphasizing its dualistic impact on both CO2 capture and geological CO2 storage. We first summarize recent advances from computational simulations and experimental characterizations, highlighting the altered thermodynamic and structural features, dynamic behavior, dielectric properties, and chemical reactivity of nanoconfined water. We then integrate insights from surface chemistry, materials science, and geoscience to elucidate how nanoconfined water influences CCS processes through competitive adsorption, pore accessibility, wettability, solubility, and mineralization kinetics, spanning systems from nanoporous adsorbents such as zeolites, metal–organic frameworks (MOFs), and activated carbon (AC) to unconventional formations including shale and tight sandstone. These findings also suggest opportunities for practical applications, such as guiding the design of hydrophobic MOFs for improved CO2 capture and supporting strategies to preserve caprock integrity in subsurface storage. Finally, we identify key challenges in bridging molecular-level understanding with material- and reservoir-scale performance, emphasizing the need for multiscale experimental techniques, realistic molecular modeling, and cross-disciplinary strategies to fully harness the functional potential of nanoconfined water in CCS.
In this article, we resolve the apparent contradiction between recent experiments and earlier theoretical studies predicting strongly asymmetric condensates resulting in an attractive interaction between condensate magnons. We show that the relaxation time required to achieve equilibrium of the two condensates at the two energy minima exceeds the experiment duration. Therefore, the system is inherently out of balance and must be described by Boltzmann’s kinetic equations. We develop an appropriate kinetic theory and derive the relation between the critical pumping power and the effective temperature of over-condensate magnons.
Vertical graphene (VG) is a promising carbon material for optoelectronics applications owing to its strong light absorption and abundant edge sites. Compared with silicon-based devices, directly integrating VG on diamond substrates enhances interfacial bonding and reduces phonon scattering, enabling superior stability and performance. However, the influence of plasma–substrate interactions under bias on the structural and functional evolution of VG has not been fully understood. In this work, VG was synthesized on diamond using a direct current bias-assisted plasma-enhanced chemical vapor deposition system under controlled negative bias voltages of 90 V, 120 V, and 150 V. The results show that moderate bias promotes vertical alignment, with nanoflakes reaching ~2.6 µm in height, exhibiting multilayer stacking and cauliflower-like morphology, while excessive bias causes disorder and plasma instability. Optical characterization reveals broadband absorption exceeding 85% from 400 to 2400 nm and electrical testing demonstrates a minimum sheet resistance of 48.6 Ω/☐ with conductivity up to 2060 S·cm−1. Kelvin probe force microscopy further shows work functions of ~5.00–5.08 eV, and confirms bias-dependent modulation of surface potential linked to defect-assisted Fermi-level tuning. These findings confirm that bias-assisted growth enables precise control over VG morphology and properties. The optimized DC plasma process provides a robust route to fabricate high-quality VG/diamond heterostructures, while the resulting all-carbon system exhibits excellent photoelectric performance, highlighting its potential for broadband optoelectronic applications.
The response of metal nanowires to external mechanical loads is a central issue for the design of devices where nanowires play an active role; this response may depend not only on the composition and thickness of the nanowire, but also on the crystallographic orientation of the nanowire with respect to its main axis. In this study, we performed a set of molecular dynamics simulations of tensile tests in a displacement-controlled environment of AuPd nanowires of several diameters and compositions, grown in the [ 100 ] , [ 110 ] , and [ 111 ] directions. We found that the [ 100 ] nanowires have a Young’s modulus about 60 GPa lower than that of the [ 111 ] nanowires, with the [ 110 ] nanowires showing intermediate values. Moreover, the [ 100 ] nanowires exhibit the highest tensile strength. In the plastic regime, the nucleation of highly mobile Shockley dislocations creates stacking faults, and, less frequently, nanotwins. The displacement of the dislocations provokes abrupt drops in the stress–strain curve, but, when a stacking fault crosses another, stress accumulates, in particular in [ 110 ] nanowires, where hardening is common, mainly due to the presence of stair-rod dislocations.
We report on the structural analysis of nickel (Ni)/nickel oxide (NiO) nanoparticles (NPs) synthesized in deionized water (DI) using the pulsed laser ablation in liquid (PLAL) technique. The laser-generated NPs exhibit a bimodal size distribution. The structural analysis of the as-produced NPs using microscopic techniques reveals the formation of a core–shell structure along with three distinct features of Ni/NiO nanostructures, namely, nanosheet, hollow, and chain-like formations. The formation of these structures is attributed to the physical properties of the liquid medium and the cavitation bubble (CB) dynamics that occur during the PLAL process. The formation of nanosheet-like structures in the nanocolloid is attributed to the deformation of the CB and the presence of high pressure at the bubble-target interface during collapse. The formation of the hollow NPs is attributed to the Kirkendall effect, while nanochain-like structures result from the post-ablation effects and localized reheating and melting during the PLAL process. The selected area electron diffraction pattern analysis reveals the presence of both Ni and NiO phases, indicating that the synthesized NPs are polycrystalline. Furthermore, based on the experimental findings, the possible growth mechanisms for the formation of different Ni/NiO nanostructures in DI are discussed.
The corrosion of pipelines remains a critical challenge for not only the oil and gas industry but also other infrastructures where carbon steel is used, which results in significant operational risks, environmental hazards, and financial losses. This condition presents a pressing need for effective and sustainable pipeline corrosion mitigation that ensures public safety, asset protection, and zero environmental tolerance. Polymer nanocomposite coatings offer a promising solution for effective corrosion mitigation, yet optimizing their composition for long-term durability and integrity management poses a complex task. The complexity in the use of polymer nanocomposites results from their nanoscale structure, which requires proper formulation to ensure their effectiveness. Property optimization of the nanocomposite structure is necessary to position the coating material to function effectively. This paper reviews the mechanisms by which PNCs mitigate corrosion, including their barrier formation, electrochemical insulation, and self-healing capabilities. It further examines how nanofillers contribute to property optimization, improving toughness, abrasion resistance, and chemical durability. The role of PNCs in integrity management is also discussed, with emphasis on their performance in complex coupled environments. While laboratory results are promising, industrial scalability, cost, and environmental safety remain key challenges. The paper concludes with recommendations for future research. One takeaway from this review, amongst others, is that real-life systems are rarely linear, and world processes involve multiple interacting variables which require us to understand how inputs affect response outcomes.
The presence of arsenic in water for human consumption is a dramatic problem that causes serious health problems. Inorganic As species (As(III) or As(V)) are the most common and toxic forms, of which As(III) is the most harmful, mobile and difficult to remove; therefore, preoxidation into As(V) is generally performed in removal procedures. Irradiation using UV-Vis light is a way to enhance the oxidation of As(III) when using zerovalent iron nanoparticles (nZVI). In this study, As(III)-containing solutions of high concentrations (1–10 mg l−1) at a circumneutral pH were treated with commercial nZVI (with an average 50 nm particle size) using different molar ratios (MRs) of As(III) to total iron under UVC irradiation (with a 254 nm germicidal lamp). The optimal conditions for the treatment were an initial As(III) concentration of 1 mg l−1, an MR = 1:30, and a pH of around 6. The oxidation was enhanced compared with that in experiments in the dark and heightened with an increase in the amount of nZVIs. A mechanism was proposed. The most important features of this 254 nm system are that the As(III) oxidation by the nanoparticles is enhanced by UVC irradiation, compared with that in the same experiments under UVA-Vis light (centered at 365 nm), because a higher amount of H2O2 is formed and adding external H2O2 is not needed. The As(V) formed remains partially adsorbed onto the final iron products and partially dissolved in the suspension, from which it can later be removed using conventional technologies. The process is efficient, low-cost, and easily scalable.
This review provides a comprehensive overview of recent advancements in the field of Rhenium(I) tricarbonyl complexes integrated within polymeric structures. It delves into the rich morphological behavior of these materials, from the self-assembly of nanoaggregates to the formation of complex, environmentally sensitive architectures. Furthermore, it examines their pivotal roles in addressing key environmental challenges through both electrocatalytic and photocatalytic CO2 reduction, highlighting strategies like electropolymerization and the use of porous organic frameworks. Finally, emerging applications in bioimaging and therapeutics, where these polymers serve as theranostic probes and drug delivery vehicles, are discussed. The overarching goal is to underscore how the polymeric environment profoundly influences the self-assembly, excited-state dynamics, and catalytic performance of Re(I) complexes, offering critical insights for the future design of advanced functional materials.
Hydrogen is gaining attention as a sustainable energy source, and its efficient production relies on cost-effective electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in the water-splitting process. Meanwhile, transition metal dichalcogenide (TMDC) nanoflakes, with diverse shapes and sizes, are widely studied for their abundant active sites that boost catalytic performance. In this study, we employed density functional theory (DFT) to investigate the structural, electronic, and catalytic properties of WSe , 2 triangular nanoflakes. We also studied the impact of noble metal functionalization (Pd, Pt, Ru, and Rh) on the HER and OER activity of triangular nanoflakes. Our analysis revealed the presence of localized metallic states at the edges of the nanoflake, where catalytic activity is significantly higher compared to the bulk sites. Additionally, we found that noble metal functionalization greatly enhances catalytic performance. Among them, Pt-functionalized WSe , 2 triangular nanoflakes exhibit the most promising HER activity. Furthermore, the application of an external potential makes the OER process energetically favorable for Pd, Pt, and Rh functionalized nanoflakes. These findings highlight the potential of noble metal functionalized WSe , 2 triangular nanoflakes for efficient electrocatalysts in sustainable water-splitting processes.
