Search Results (34,477)

X-ray techniques provide powerful, non-destructive tools for structural characterization in semiconductor manufacturing and advanced packaging. Their strong penetration capability and sensitivity to multiple contrast mechanisms enable the investigation of lattice structure, strain, defects, interfaces, and elemental distribution across a wide range of length scales. As semiconductor devices evolve toward three-dimensional architectures and heterogeneous integration, there is an increasing demand for characterization approaches capable of probing complex, buried, and multi-scale structures in a consistent manner. In this review, we present a systematic overview of X-ray characterization techniques for advanced semiconductor systems, including diffraction-based methods, small-angle scattering, computed tomography, X-ray fluorescence, and spectroscopic approaches. These techniques are discussed in terms of the type of structural, morphological, and compositional information they provide, their applicable length scales, and their strengths and limitations in addressing key challenges such as thin films, high-aspect-ratio structures, buried interfaces, and full wafers. Particular attention is given to the complementary nature of different X-ray modalities and their roles in addressing practical metrology problems. The limitations associated with resolution, model dependence, and data interpretation are also outlined. Finally, emerging opportunities in laboratory X-ray sources, synchrotron-based methods, and integrated characterization strategies are briefly discussed. This review aims to provide a unified perspective for understanding and integrating X-ray techniques, offering insights into their roles in addressing the growing complexity of next-generation semiconductor devices. Full article

This study investigates the effect of polyvinyl alcohol (PVA) on the performance of natural hydraulic lime (NHL)-based repair mortars used in historical building restoration. Mortars were prepared with varying PVA dosages (0.25%, 0.5%, 0.75%, and 1.0%) to evaluate their impact on physical, mechanical, and durability properties, including setting time, strength, water absorption, shrinkage, and resistance to freeze–thaw and sulfate attack. The results demonstrate that PVA significantly enhances bonding strength, reduces water absorption, and improves durability, with optimal performance observed at a 0.5% PVA dosage. Microstructural analysis showed that PVA forms a cohesive film, reinforcing the mortar’s structure. These findings suggest that PVA can enhance the performance of NHL-based mortars, offering significant potential for historical building restoration, particularly under challenging environmental conditions. Full article

The widespread presence of stable and hazardous organic contaminants, such as synthetic dyes, in industrial effluents necessitates the development of resilient treatment strategies capable of achieving efficient degradation and decolorization of dye pollutants. Conventional treatment processes often fail to remove such recalcitrant compounds, prompting growing interest in integrated advanced systems. Photocatalytic membranes represent a promising solution due to the synergistic combination of physical separation and catalytic degradation. In this study, zinc oxide (ZnO) thin films were deposited by spin coating onto smectite–zeolite ceramic membranes (MS10/Z90), applying one (M1), two (M2), and three (M3) successive coating layers to control catalyst thickness. SEM analysis confirmed that increasing the number of layers resulted in a thicker and more homogeneous ZnO coating, while XRD revealed enhanced crystallinity and larger crystallite size. Water permeability decreased progressively from 623 L·h⁻¹·m⁻²·bar⁻¹ for the uncoated membrane to 506, 439, and 350 L·h⁻¹·m⁻²·bar⁻¹ for M1, M2, and M3, respectively. Photocatalytic performance was evaluated using Rhodamine B (RhB) (10 mg·L⁻¹) under UV irradiation (365 nm, 18 W) for 180 min, achieving degradation efficiencies of 83.0%, 94.6%, and 99.1% for M1, M2, and M3, respectively. The degradation kinetics followed a pseudo-first-order model, with rate constants increasing with catalyst layer thickness. Free radical scavenging assays confirmed that hydroxyl radicals (•OH) were the primary reactive species responsible for RhB degradation. These findings highlight the critical influence of ZnO layer thickness and mass transfer on photocatalytic performance, demonstrating the potential of ZnO-coated ceramic membranes for efficient pollutant degradation and in situ photocatalytic regeneration. Permeability measurements after photocatalytic treatment confirmed effective flux recovery, supporting the operational durability of the developed membranes. Full article

Heavy metal contamination of drinking water remains a persistent global challenge, exacerbated by salinity, industrial discharge, and the limitations of existing membrane technologies that are constrained by permeability–selectivity trade-offs. In this study, we develop a hybrid thin film nanocomposite (TFN) forward osmosis (FO) membrane by incorporating a zirconium-based metal–organic framework (UiO-66) and its conductive polymer-functionalized analogue (PANI@UiO-66) into the polyamide active layer via interfacial polymerization. The incorporation of UiO-66 enhances water transport through the introduction of hydrophilic microporous domains, while the polyaniline coating modulates nanoscale transport pathways and interfacial interactions. Systematic variation in filler type and loading reveals distinct functional roles of the two fillers. Membranes incorporating bare UiO-66 exhibit increased water flux, attributed to facilitated transport through MOF-derived nanochannels, but show a moderate increase in reverse solute flux. In contrast, PANI@UiO-66 incorporation results in reduced water flux but significantly suppresses reverse solute flux and enhances chromium rejection, indicating improved control over selective transport. At an optimal loading of 0.15 wt% (TFN-PU3), the membrane demonstrates an improved balance between water permeability and solute selectivity compared to the pristine thin film composite (TFC) membrane under FO conditions. The observed performance is attributed to the combined effects of modified transport pathways and interfacial interactions introduced by the hybrid filler system. The results highlight the potential of conductive polymer–MOF hybridization as a strategy for tuning membrane performance. This work provides a practical framework for designing TFN membranes for selective heavy-metal removal in saline and complex water environments. Full article

Oxidative aging drives asphalt pavement degradation, causing critical structural failures. This study evaluated hazelnut (HS) and walnut shell (WS) powders (0–3% w/w; 10–12 μm) as sustainable antioxidants, from valued residues, to mitigate thermo-oxidative aging in CA-24 binders. After evaluating the antioxidant potential (ORAC; Oxygen radical absorbance capacity, and TPC; Total phenolic content), modified binders underwent RTFO (Rolling thin film oven) and PAV (Pressure aging vessel) aging, evaluated by Fraass fragility, Relative Aging Index (RAI), dynamic shear rheometry (G*/sin δ), and Multiple Stress Creep Recovery (MSCR). WS exhibited significantly higher antioxidant capacity (6000 μmol TE g DW⁻¹) and TPC than HS. The 3% treatments demonstrated optimal antioxidant efficacy, reducing long-term RAI by 14% and improving low-temperature flexibility by 3.8 °C (Fraass point −12.3 °C). However, MSCR revealed initial plasticizing effects decreasing elastic recovery (70%) and increasing non-recoverable compliance (Jnr) compromising unaged rutting resistance. Principal component analysis confirmed progressive diversification of aging-induced properties, evidencing complex multivariate trajectories. Ultimately, while nutshell derived phenolic modifiers provide effective concentration-dependent antioxidant protection, practical application requires optimization through targeted phenolic extraction, particle engineering, or elastomeric co-modification. Balancing aging resistance with high temperature stability remains essential for advancing these sustainable biomodification strategies in road infrastructure. Full article

Microfluidics enables spatially controlled nanostructure synthesis by coupling confined flows with surface reactions. In this work, we study how geometry-induced laminar microenvironments govern the in situ formation of Au and Ag nanostructures inside 3D-printed microfluidic reactors. Proof-of-concept fish-scale valves were fabricated by masked stereolithography in three architectures designed to define three recurring zones in the microreactor, inside the fish-scales (zone 1), between the fish-scales (zone 2), and along the rows of fish-scales (zone 3). A Cu thin film was deposited on the inner walls of the channel to serve as the sacrificial surface for galvanic replacement using AgNO₃ or HAuCl₄. Distinct 0D, 1D, and 2D nanostructures were simultaneously obtained in a zone-dependent manner across the valves, including nanoparticle and nanopore-rich regions, nanowires, nanoflakes and clustered 2D features. COMSOL simulations were used to solve the Navier–Stokes equation and extract specific-zone flow descriptors, including Reynolds number, velocity, and wall shear stress, and relate them to the nanostructure morphologies observed by SEM. The flow throughout the devices is strongly laminar, with local Reynolds numbers up to 0.04, exhibiting systematic spatial gradients imposed by the valve geometry. These results provide a design-guided route to tune nanostructure morphology through microchannel architecture under constant global operating conditions. Full article

All-inorganic cesium lead iodide (CsPbI₃) has been investigated for more than a decade as an absorber for perovskite photovoltaics thanks to its attractive bandgap, thermal robustness compared with hybrid perovskites, and compatibility with tandem concepts. Yet, despite remarkable efficiency progress, CsPbI₃ remains far from widespread commercialization. The core roadblock is the metastability of the photoactive black perovskite phases (α/γ/β) against transformation to the photoinactive yellow δ-phase under realistic conditions, amplified by defect chemistry, ion migration, and interfacial reactions. Additional barriers arise from scale-up constraints (film uniformity, throughput, solvent management), long-term operational stability (humidity, heat, UV, bias), and environmental/safety requirements, especially lead containment, sequestration, and end-of-life strategies. This review critically analyzes the intertwined physical, chemical, and engineering factors that still limit CsPbI₃ deployment, with emphasis on how solutions in one domain can fail without co-design in others. This review summarizes state-of-the-art stabilization strategies (size/strain engineering, additive/doping routes, surface/interface passivation, and encapsulation), highlight scalable manufacturing pathways including solvent-minimized and vacuum-assisted approaches, and discuss lead-mitigation technologies such as Pb-adsorbing functional layers. Finally, I argue that artificial intelligence (AI)—from machine-learning stability models to process monitoring, robotic optimization, and digital twins—has become essential to navigate the enormous parameter space of CsPbI₃ materials and manufacturing. It concludes with actionable recommendations and future directions toward bankable, scalable, and sustainable CsPbI₃ photovoltaics. Full article

ALD is a precise thin-film deposition technique based on self-limiting surface reactions. A crucial stage in each ALD cycle is the purge step, which removes excess precursor molecules and reaction by-products from the reactor chamber, preventing uncontrolled gas-phase reactions that could degrade film quality. Despite its fundamental importance, the impact of purge dynamics on film growth and structure remains insufficiently explored. ZnO and ZrO₂ films were deposited in reactors with different effective chamber volumes (47 and 470 cm³), enabling a systematic study of gas residence time effects. Our results demonstrate that the purge mode—dynamic versus static vacuum—strongly affects the growth behavior, crystallinity, and surface morphology of ALD oxides. Dynamic purging leads to smoother, more uniform, and better-crystallized films, whereas static exposure results in lower structural and morphological quality, particularly for ZrO₂. Importantly, these results demonstrate that purge-mode engineering provides a powerful and cost-effective route for tailoring oxide film structure without altering the precursor chemistry or deposition temperature. To validate the practical integration of these optimized films, functional phosphor and LED structures were fabricated, confirming that the controlled microstructure is well-suited for optoelectronic applications. This approach also offers new possibilities for controlling film properties in sensors and catalysts. Full article

SiSn alloys have attracted growing interest for group-IV bandgap engineering, although their epitaxial growth remains challenging due to the extremely low equilibrium solubility of Sn in Si. In this work, fully strained (pseudomorphic) SiSn epitaxial layers were grown on Si (001) substrates by means of molecular beam epitaxy. A systematic investigation reveals a strong inverse correlation between growth temperature and Sn incorporation efficiency. Despite a constant Sn flux, the incorporated Sn composition decreases from 5.5% to 3.2% as the growth temperature increases, indicating a pronounced temperature dependence of Sn incorporation. Reflection high-energy electron diffraction indicates a gradual transition of the growth from two-dimensional to three-dimensional with increasing film thickness. Structural characterization by means of X-ray diffraction, atomic force microscopy, and transmission electron microscopy confirms the pseudomorphic growth and smooth surface morphology and reveals twins and stacking faults near the surface region. These results establish a quantitative reference for SiSn growth kinetics and provide guidance for future studies of SiSn and SiGeSn alloys in silicon-compatible electronic and optoelectronic applications. Full article

Polyetherimide (Ultem-1000) hollow-fiber membranes were developed for biogas purification with emphasis on the relationship between spinning conditions, membrane morphology, gas transport properties, and module performance. Hollow fibers were prepared from dope solutions based on dimethylformamide (DMF) and N-methyl-2-pyrrolidone (NMP) at different conditions, followed by post-treatment with 1 and 3 wt.% silicone solution in n-heptane to reduce nonselective defects and improve selectivity toward the intrinsic behavior of dense PEI films. SEM analysis revealed that DMF-based fibers formed a more open, macrovoid-rich structure, whereas NMP-based fibers exhibited a more homogeneous sponge-like morphology with a better-defined selective layer. DMF-based fibers experienced faster demixing, which promoted macrovoid formation, increased pore connectivity of the substructure, lowered mass transfer resistance, and at the same time increased the probability of nonselective pathways and defect-related loss of selectivity. This structural evolution was reflected in gas transport properties: untreated DMF fibers showed high mixed-gas permeance but limited selectivity, while NMP fibers demonstrated lower permeance and selectivity values closer to those of the dense film. Silicone post-treatment significantly improved separation performance, with 3 wt.% coating being markedly more effective than 1 wt.% coating. The best compromise between permeance and selectivity was achieved for the DMF-based fibers treated with 3 wt.% silicone, which exhibited CO₂ and H₂S permeances of 39.4 and 47.12 GPU, respectively, together with selectivity values of 22.4, 26.8 and 20.2 for CO₂/CH₄, H₂S/CH₄ and CO₂/N₂. A membrane module containing 500 fibers was studied during the quasi-real biogas upgrading. With increasing stage-cut, the CH₄ concentration in the retentate increased from ~74 to 96 mol.%, while CO₂ decreased from ~21 to 2 mol.%. The results demonstrate that structure control combined with silicone post-treatment is an effective strategy for producing PEI hollow fibers suitable for simultaneous methane enrichment and removal of acid impurities from biogas. Full article

The growing demand for sustainable construction has highlighted the need to effectively utilize solid waste materials in concrete production, yet achieving satisfactory workability, strength, and durability simultaneously remains challenging. A multi-parameter mix-design methodology is proposed for solid-waste-based self-compacting concrete (SCC). This method couples minimum water demand, control of paste film thickness, and multi-performance balancing. The ternary solid-waste powder system (silica fume, fly ash, and supersulfated solid-waste-based cement) was first optimized through minimizing water demand to achieve maximum packing density. The resulting composition was then blended with varying dosages of ordinary Portland cement (OPC) to form the final cementitious binder. Aggregate gradation was proportioned to minimize voids, and paste volume was determined using an equivalent-paste-film-thickness model. Under comparable mixture conditions, SCC with OPC contents of 70–40 wt.% and paste film thicknesses of 2.0–2.6 mm was evaluated for fresh performance, compressive strength, freeze–thaw resistance, and material cost. Mixtures with a paste film thickness of 2.4 or 2.6 mm satisfied the self-compactability criterion—the mix with 50 wt.% OPC and a paste film thickness of 2.4 mm showed the best overall performance balance, achieving higher 28 d strength than higher-OPC mixtures while improving freeze–thaw resistance and reducing cost. Results from TGA, XRD, ATR–FTIR, and SEM–EDS analyses indicated enhanced calcium hydroxide (CH) consumption, increased formation of C-(A)-S-H and ettringite, and a denser interfacial transition zone (ITZ), supporting the proposed multi-objective design approach. While the framework was validated for a specific ternary binder system, it provides a reproducible proportioning strategy applicable to a broader range of solid-waste-based concrete systems, with potential for extension to other waste streams and exposure conditions, thus supporting the development of more resource-efficient and environmentally sustainable concrete. Full article

Delamination remains a critical limitation in the structural application of wood, particularly in adhesively bonded joints. This study investigates the use of a cyclic olefin-based hot-melt film adhesive (Zeon^® LS-XU) as a thermoplastic interlayer as a means to delay delamination and enhance joint performance. Single lap joints (SLJs) were tested under quasi-static (1 mm/min) and impact (3 m/s) loading to assess strain-rate effects. Six configurations were examined: two reference, two toughened (with an additional 15 mm of adhesive on each overlap side) and two hybrid configurations combining oak (Quercus alba) and pine (Pinus pinaster Aiton) substrates to improve stress wave propagation. A finite element elastic model was developed to analyse stress distributions and explain the superior performance of hybrid joints. Results revealed that the thermoplastic interlayer delayed delamination onset and increased energy absorption, while hybrid configurations achieved more uniform stress distributions and significantly higher strengths under dynamic loading. The most effective configuration, the hybrid joint under impact conditions, represents a strength improvement of approximately 84% of the peak load compared to the pine reference joints. Overall, introducing a thermoplastic interlayer offers an efficient and lightweight strategy to enhance the toughness and reliability of wood joints exposed to variable loading conditions. Full article

Existing buildings with large glazing ratios within subtropical Mediterranean climates face substantial challenges for thermal and visual control of their indoor environment. Previous research by the same authors has already identified the potential of incorporating both solar–PDLC (polymer-dispersed liquid crystal) and SPD (suspended particle device) switchable films within facades exposed to high solar insolation to provide a wide dynamic range of visual transparencies. This paper identifies a novel application for switchable laminates within a dynamic external shading device that permits the casting of a shadow on demand onto existing fenestration. This study compares the degree of glare within an enclosed space attained by a conventional opaque overhang over a window to that achieved with glass shading overhangs incorporating two types of switchable films. Using a scale model in a field test setting, indoor illumination and glare measurements are investigated under different states of switchable films and compared to those provided by conventional static glazing, with and without ordinary external overhangs under identical field test conditions. Results show that switchable overhangs in their transparent/bleached state can allow the ingress of daylight without creating excessive glare, whereas in their translucent/tinted state, switchable shades can deliver a level of glare protection similar to that provided by an opaque shading overhang. Full article

To develop cosmetic film-forming agents that combine sustainability with functionality, this study synthesized a series of bio-based polyols using epoxidized soybean oil (ESO) as raw material through acid-catalyzed ring-opening reactions. These polyols partially replaced petroleum-based polyols and reacted with isophorone diisocyanate (IPDI). By incorporating β-cyclodextrin (β-CD), a water-based polyurethane (CPS-ESO) was successfully developed that combines degradability with active ingredient delivery capability. Experiments demonstrated that the resulting CPS-M film exhibits excellent water repellency (contact angle 66.7°), mechanical properties (tensile strength 14.21 MPa, elongation at break 229.42%), adhesion (Level 0), and breathability, while displaying controllable degradation behavior under both enzymatic and alkaline hydrolysis conditions. Due to the cavity structure of β-cyclodextrin, this material efficiently loaded resveratrol (RES) at a loading rate of 0.16%. Formulated into a setting spray (F1), the product demonstrated outstanding makeup longevity (lowest ΔE value after water/sweat immersion), anti-friction performance (ΔE value after friction only one-third of the control group), and antioxidant activity (DPPH scavenging rate of 86.25%), with RES remaining stable under high-temperature storage conditions. This study provides new insights for designing green multifunctional cosmetic film-forming agents. Full article

Wearable electrodes have attracted attention for their ability to monitor human electrophysiological signals, such as those generated by the heart and captured via electrocardiography (ECG). In this study, an easy and scalable drop-coating method was used to develop flexible, dry, and sustainable ECG electrodes composed of a poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)/polyvinyl alcohol/xanthan gum (PXP) composite. The electrodes were fabricated on different cellulosic substrates, such as Xuan paper, Kraft paper, and wheat bagasse, and further modified through the incorporation of MoO₃ (PXPM composite). PXP exhibits a broad absorption band of 350–550 nm, while PXPM shows a shifted band of 400–750 nm, due to the interaction of MoO₃ with PEDOT:PSS. The fluorescence emission of PXP appears at 443 nm, while the emission for PXPM is broader and centered at 437 nm. Electrically, both composites exhibit continuity and ohmic behavior. Microstructural analysis revealed that the interaction between the composite film and the substrate strongly influences pore formation, film uniformity, and the distribution of Mo species, highlighting the role of MoO₃ as an interfacial modifier that promotes smoother and more homogeneous coatings on selected cellulosic substrates. All fabricated electrodes demonstrated the capability to detect ECG signals with sufficient quality to be clinically valid. Full article