Search Results (423)

This study explores the development of low-friction, water-based coatings tailored for industrial applications in pharmaceutical glass packaging. The study focuses on scalable deposition strategies to obtain durable low-friction coatings suitable for industrial implementation. To balance mechanical performance and application efficiency, two different application approaches based on a two-component coating (aminosilane primer and lubricant) were investigated. In the first case, the coating is deposited in two steps, while in the second, a single deposition step is used. Characterization through contact-angle measurements and X-ray photoelectron spectroscopy confirmed successful deposition of the primer on the glass surface. Scratch resistance tests revealed an increase in the critical load for fracture initiation from 4.5 N for uncoated glass to 6.5 N for the best-performing coating, indicating improved resistance to surface damage. Friction performance was assessed via tribological tests, which demonstrated that the primer–lubricant coatings achieved the lowest coefficient of friction (approximately 0.2), compared with uncoated glass (stabilizing at approximately 0.3 after an initial value of 0.5) and lubricant-only coatings (approximately 0.4–0.5), confirming the beneficial role of the primer in the coating system. Representative profilometry measurements indicated sub-micrometric coating thicknesses, while UV–Vis measurements confirmed that the coatings preserved the high optical transparency of the glass substrate, with average visible transmittance values above 90%. Furthermore, the successful implementation of the coating using an automated spray system demonstrates its potential for scalable industrial production. These findings support the potential of environmentally sustainable water-based coatings for pharmaceutical glass packaging by combining improved mechanical performance with preserved optical transparency and compatibility with scalable spray deposition. Full article

Glass additive manufacturing (AM) is a developing technology, particularly in comparison to metals and polymers, both of which have had their processes and applications extensively studied. Its potential lies in fabricating complex, even micrometric, geometries that are difficult or impossible to achieve via traditional molding, as well as in producing components with unique optical properties. The diversity of AM techniques, alongside the challenges associated with the high melting point, rheological control, and fragility of glass, necessitates a comprehensive analysis of current developments. Accordingly, this review presents a systematic review, conducted in accordance with the PRISMA protocol, of recent literature regarding AM technologies that fabricate glass via particle fusion to form solid components. This review explicitly excludes techniques utilizing glass fibers as reinforcement, as that constitutes a separate field of inquiry. The results demonstrate sustained growth within the field, with a predominance of technologies based on photopolymerization and ink extrusion, both of which offer high resolution and microstructural control. Ultimately, this review establishes the current state of the art, identifying critical challenges and emerging lines of research to guide future development. It is intended to serve as a foundational reference for researchers and professionals seeking to initiate or expand their work in glass AM. Full article

Non-steroidal anti-inflammatory drugs (NSAIDs), including naproxen, are widely used for the treatment of pain and inflammation; however, their therapeutic application is limited by poor aqueous solubility and low bioavailability. This study aimed to synthesize and characterize a novel amino acid-based naproxen derivative, L-phenylalanine menthol ester naproxenate ([PheOMent][NAP]), develop liposomal formulations containing the obtained compound, and evaluate their physicochemical properties and transdermal delivery potential. The derivative was synthesized via a three-step procedure and characterized using NMR, FT-IR, TG, DSC, and XRD analyses. Compared with naproxen, [PheOMent][NAP] exhibited lower lipophilicity (log P = 1.36 vs. 1.70). Liposomal formulations containing the modified derivative showed high encapsulation efficiency (89.6–90.7%), higher than that observed for naproxen-loaded liposomes (51.7–54.7%). The prepared systems exhibited bimodal particle size distributions, comprising both submicrometre and micrometre vesicle populations depending on the preparation method, as well as negative zeta potential values (−18.17 to −23.72 mV) and pH values ranging from 6.18 to 7.07, demonstrating physicochemical characteristics suitable for topical formulations. In vitro permeation studies using porcine skin demonstrated markedly enhanced transdermal delivery of [PheOMent][NAP]. After 24 h, cumulative permeation exceeded that of naproxen formulations by more than 1.5-fold (416.7 vs. 281.6 μg cm⁻²). These findings indicate that liposomal formulations containing amino acid-modified naproxen derivatives represent a promising strategy for improving transdermal NSAID delivery. Full article

Techniques such as adsorption have been widely adopted to remove residual microplastics (MPs) because they are efficient at removing contaminants from aqueous environments. In this study, we report a novel, low-cost, biodegradable, and scalable biocomposite (LCMAG NaOH) derived from Luffa cylindrica fruit (LC) and micrometric natural magnetite (MAG), prepared without organic solvents, for the removal of MPs. The performance of LCMAG NaOH was evaluated for the removal of polystyrene (PS) and polyethylene terephthalate (PET) MPs, with particle sizes ranging from 75 to 600 µm in three distinct aqueous media: drinking water, simulated seawater, and water collected from the eutrophic lake of Dourados, MS, Brazil. The material was also evaluated for capture capacity and for reutilization in drinking water over three cycles, using a neodymium magnet. The biocomposite exhibited maximum removal capacities of 163 mg g⁻¹ and 158 mg g⁻¹ for PS and PET, respectively, in drinking water. Additionally, it demonstrated high magnetic recovery efficiency (>90% of the initial mass) and good reusability after immersion (10 and 20 min) and a dry step during the first cycle. Full article

Bismuth hexacyanoferrate (BiHCF), a Prussian blue analogue containing redox-active Fe–CN–Bi coordination motifs, was investigated as a model electrode for cathodic processes in chloride-rich saline and hypersaline electrolytes. Rather than evaluating BiHCF solely as a hydrogen evolution catalyst, this work focuses on the coupled electrochemical and interfacial processes that govern its response in NaCl solutions and natural brines from seawater, reverse osmosis (RO) reject, and high-altitude brine environments. Structural characterization by SEM–EDS, XRD and FTIR confirmed the formation of crystalline BiHCF with rod-like micrometric morphology and preserved cyanide coordination. Linear sweep voltammetry under controlled hydrodynamic conditions revealed a progressive cathodic displacement of the mixed potential with increasing NaCl concentration, together with a marked suppression of oxygen reduction kinetics at high chloride activity. Mixed-potential analysis showed that HER kinetics remain comparatively less sensitive to salinity than ORR, whereas the anodic contribution associated with BiHCF oxidation becomes strongly affected by chloride-induced surface transformation. Post-electrochemical characterization indicates the formation of a BiOCl-rich surface layer when the BiHCF is in contact with a hypersaline electrolyte during the cathodic subprocess (close to 0 mV_SHE), which accounts for the transition from active mixed-control behaviour to a passivated interfacial regime. Density functional theory calculations suggest that elementary water activation and hydrogen-forming steps at Bi sites are intrinsically feasible, implying that the experimentally observed overpotentials originate primarily from transport, interfacial resistance and chloride-driven passivation rather than from an unfavourable molecular reaction pathway. These findings provide a mechanistic framework for understanding Bi-based Prussian blue analogue electrodes in non-purified saline electrochemical systems and highlight the dual role of chloride as both a charge-compensating electrolyte species and a passivating reactant. Full article

Nanoplastics (NPs; ≤1 µm) have been detected in human placenta, blood, lung, atherosclerotic plaque, testis, semen, olfactory bulb, and brain, shifting the field from environmental description toward mechanistic interrogation of barrier crossing. This review synthesises current evidence on NP translocation across the intestinal epithelium, the blood–brain barrier (BBB) and the placental syncytiotrophoblast. We distinguish four evidence categories throughout the review: detection, association, mechanism, and causality. We also apply model-system labels (in silico, in vitro, ex vivo, animal, and human) to every mechanistic claim, so that the strength of each statement can be read off directly. Most current studies use pristine polystyrene nanoplastics at concentrations 3–6 orders of magnitude above plausible human exposure, so the mechanistic conclusions below are hypothesis-generating for human disease rather than definitive. We propose a working conceptual framework—corona-driven barrier selectivity (CDBS)—in which the particle–corona–surface complex, rather than the bare polymer, is hypothesised to dictate which receptor and transport machinery (TfR1, LRP1, FcRn, P-gp/BCRP, caveolae) each barrier engages. CDBS is offered as a hypothesis-stage organising tool requiring experimental validation, not as an established mechanism. We outline reported transport modes, including clathrin- and caveolin-mediated endocytosis, paracellular leakage via ROS-induced tight-junction disassembly, receptor-mediated transcytosis, and the candidate olfactory route. We emphasise that pristine polystyrene-bead doses commonly exceed plausible human exposure by 3–6 orders of magnitude, that detection methods underestimate sub-micrometre particles, and that causal links between NPs and human disease remain hypothesis-generating. A research agenda built on weathered reference materials, microphysiological systems, and integrative human biomarker science is proposed. Full article

Non-invasive characterization of painting stratigraphy is challenged by light attenuation in optically heterogeneous opaque materials composing micrometric layers. Optical coherence tomography (OCT) provides suitable, non-invasive, depth-resolved imaging capabilities; however, large-area stratigraphic analysis is limited by the restricted field of view of individual stacks, high data dimensions, and the lack of robust methods for stitching volumes acquired at different focal depths. In addition, conventional layer thickness estimation relies on manual identification of intensity peaks along A-scans, which is time-consuming, operator-dependent, and unsuitable for large-scale analysis. Building upon our prior work, which introduced an AI-enhanced method for OCT volume analysis, we present an automated workflow integrating supervised semantic segmentation, volumetric mosaic stitching, and pixel-wise layer thickness quantification. OCT B-scans are segmented using a Random Forest classifier within the Trainable Weka Segmentation framework to delineate material interfaces. Adjacent OCT volumes are then combined into a continuous mosaic, and interfacial distances are computed using a custom MATLAB routine to obtain pixel-wise thickness measurements over extended fields of view. The model discriminates air/paint and paint/primer interfaces with an accuracy ranging from 96.4% to 97.1% and a weighted average F1-score exceeding 0.95, enabling quantitative reconstruction of paint thickness with micrometric resolution. This method enables efficient and reproducible analysis of large OCT datasets, extends stratigraphic characterization to macroscopic fields of view while maintaining micrometric resolution, and reduces processing time while improving consistency compared to manual approaches. Full article

Quaternary β-Ti-xTa-xZr-xNb (TTZN) alloys (x = 10, 20, and 30 wt%) were surface-modified by plasma electrolytic oxidation (PEO) to improve their surface properties. This treatment promotes the incorporation of bioactive ions, such as Ca and P, and favors the formation of a porous anodic surface resulting from the oxidation of the precursor metals. This study investigated how the addition of alloying elements (Zr, Ta, and Nb) influences oxide formation, PEO-induced pore morphology, wettability, and coating hardness. The surfaces were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS), Vickers microhardness testing, and wettability analysis. XRD analysis revealed that the TTZN10 alloy exhibited crystalline TiO₂ phases in the form of anatase and rutile. In contrast, the TTZN20 and TTZN30 alloys exhibited only cubic ZrO₂ diffraction peaks, while no TiO₂ peaks were detected within the detection limits of the XRD technique. Micrographs showed micrometric pores on all alloy surfaces. The TTZN20 alloy exhibited the highest porosity (31.8%), which correlated with lower hydrophilicity (θ = 79°) and high surface free energy (67 mJ/m²). After PEO treatment, all surfaces exhibited high hardness values ranging from 491 to 561 HV. The highest hardness was observed for TTZN10, attributed to the mixed anatase/rutile TiO₂ phase composition. Full article

The ultra-short-pulse (USP) laser joining of sapphire to iron is investigated by combining electron backscatter diffraction (EBSD) and ruby (Cr³⁺) R₁ fluorescence mapping to resolve the joint microstructure and pressure distributions. Energy-dispersive X-ray spectroscopy (EDS) reveals Al, O, and Fe intermixing within the seam, consistent with the formation of thin Fe–Al–O reaction layers. R₁ fluorescence yields a maximum internal pressure of $(490\pm 80)$ MPa within the modified sapphire region and decays to near-zero within a few micrometres distance from the seam. EBSD data suggest a single-crystal sapphire lattice with localized disorientation adjacent to the joint, whereas the iron foil remains polycrystalline with rolling-induced misorientation without additional weld-induced grain refinement. These results demonstrate that USP joining of sapphire to iron produces localized interfacial reaction zones, with confined pressure predominantly occurring within sapphire. Full article

Polymer-based composites with magnetic properties are promising materials that are able to combine the usual polymer features (low density, high electrical resistance, enhanced flexibility, and processability, etc.) with magnetic properties typically associated with ferro- or ferrimagnetic metals, alloys or metal oxide. The combination of recycled NdFeB powders with additive manufacturing techniques based on material extrusion enables the production of magnetic composites. The novelty of this approach lies in the use of 3D printing supported by an external magnetic field, which is used to align the particles during the printing process and thus improve the final magnetic properties. This approach represents a sustainable strategy for the recovery of electronic waste, converting it into high-value-added magnetic materials intended for additive manufacturing applications. Micrometric particles made of a Neodymium–Iron–Boron (NdFeB) alloy are compounded with a flexible thermoplastic matrix made of polybutylene adipate-co-terephthalate (PBAT). The NdFeB alloy is recovered from permanent magnets of obsolete hard drives and is demagnetized, ground to powder under an inert atmosphere, and finally sieved to a particle size below 50 µm. The obtained powder is mixed with the polymer using a twin-screw extruder. The composite material containing the NdFeB particles is then processed to obtain a calibrated filament, used for the fused deposition modeling (FDM) three-dimensional (3D) printing of magnetic composites. To improve the composite’s ferromagnetic behavior, the particles were aligned along the stacking direction of the layers during the 3D FDM process by printing directly onto a permanent magnet placed on the build plate. Composites containing up to 50% by weight of recycled NdFeB powder were successfully processed using FDM technology, exhibiting increased stiffness, with the storage modulus rising from 123 to 178 MPa at 20 °C, while magnetic field-assisted printing increased the remanence from 11 to 28 emu/g and improved the reduced remanence from 0.21 to 0.49, corresponding to an estimated fourfold improvement in the magnetic energy product. Full article

This work presents the Smart-Reflex-Scope, a compact and accessible smartphone-based microscope with integrated reflective illumination developed for on-chip analysis of microparticle dynamics. In this work, the platform is specifically employed to characterize size-dependent microparticle motion within a microchannel. The Smart-Reflex-Scope simultaneously functions as an illumination source and imaging unit by integrating a reversed smartphone camera lens, a custom reflex module, a microfluidic chip, and a precision Z-axis translation stage for focal adjustment. The optical performance was quantitatively evaluated in terms of equivalent focal length, magnification, and object-plane spatial resolution, providing a comprehensive assessment of the system’s microscale imaging capabilities. A comparative design study was conducted between two configurations: Design-1, based on normal reflection, and Design-2, based on angular reflection. The two approaches were analyzed with respect to illumination uniformity and imaging performance to identify the optimal configuration for enhanced visualization. Experimental validation was performed using synthetic microparticles with diameters of $6\mathsf{\mu }\mathrm{m}$ and $20\mathsf{\mu }\mathrm{m}$, enabling assessment of the system’s ability to resolve and dynamically track micrometric objects of different sizes. The results demonstrate reliable detection and size-dependent dynamic characterization. A two-factor statistical ANOVA analysis confirmed the significance of the observed differences between microparticle groups under the tested experimental conditions (p-value $<0.0001$). Overall, the proposed platform represents a scalable and miniaturized microscopy solution bridging conventional benchtop instruments and portable analytical devices. Full article

In response to the significant challenges posed by ice accumulation and contamination from various fluids in complex operating conditions for metallic materials, this study utilises picosecond laser precision machining to develop a ‘slippery surface’ featuring a micro-channel network structure. The core innovation of this study lies in the use of laser-machined micrometre-scale array textures to overcome the limitations of traditional isolated pores. These globally interconnected micro-channels serve as highly efficient reservoirs and dynamic transport channels for lubricants, significantly enhancing the interfacial capillary locking force of the lubricant. Experimental results demonstrate that this unique network geometry endows the surface with exceptional fluid replenishment and self-healing properties, enabling it to exhibit outstanding broad-spectrum hydrophobicity towards various fluids—including water, crude oil and ethanol (surface tension range: 17.9–72.0 mN m⁻¹)—with sliding angles consistently below 12°, whilst effectively slowing the dehydration and solidification processes of biological fluids. At a low temperature of −15 °C, the surface achieved an ice formation delay of up to 286 s, with an ice adhesion strength of only 33.9 kPa, ensuring that accumulated ice could be spontaneously detached under minimal external force. Furthermore, the micro-channel network structure serves as a key protective mechanism against mechanical wear, maintaining robust slippery properties even after three hours of high-pressure water jet scouring (Weber number of 300). This reliable interface, achieved through structural management, provides an efficient and scalable platform for addressing the all-weather anti-icing and antifouling requirements of outdoor infrastructure. Full article

Objective: This study investigates the influence of selecting three thermoplastics as raw materials (PLA, PETG, and ABS) on dimensional accuracy, defect formation, and slicer-based mass prediction reliability in FFF 3D-printed UAV micro-frames. Methods: A factorial experimental design combining three materials, two micro-frame geometries, and two infill levels was implemented. Print quality was assessed through structured visual inspection of common FFF defects, while manufacturing reliability was evaluated by comparing slicer-predicted and experimentally measured mass. Dimensional fidelity was quantified at critical motor mount features using repeated micrometric measurements and dedicated accuracy and uniformity indices. Results: The results reveal strong material-dependent behaviour. PLA exhibited the highest dimensional consistency and near-zero mean mass prediction error, PETG showed intermediate performance, and ABS presented significant warping, together with a pronounced positive mass prediction bias. These findings indicate systematic discrepancies between predicted and measured mass values and highlight the need for material-dependent calibration of slicing software. Conclusions: Material selection and process calibration strongly affect dimensional fidelity and manufacturing reliability in FFF-printed UAV micro-frames. The findings provide practical guidance for material choice and slicing parameter adjustment in UAV fabrication and similar small-scale FFF applications. Full article

Egyptian papyri are commonly documented using high-resolution two-dimensional imaging, which enhances legibility but does not adequately capture the micrometric surface morphology required for material and conservation studies. To address this limitation, we developed and validated an integrated, fully non-contact imaging workflow combining Ultra-Close-Range Multiband Photogrammetry with Reflectance Transformation Imaging (RTI) and normal map integration. The protocol was tested on six papyrus fragments from the Museo Egizio di Torino (XXI Dynasty–Byzantine period) exhibiting different conservation conditions. Multiband photogrammetry in the visible and visible-induced infrared luminescence bands achieved a Ground Sample Distance of 17 µm/px and a point cloud density of approximately 170 points/mm², enabling detailed analysis of fiber morphology, surface deformation, and the spatial distribution of Egyptian blue. RTI-based normal map integration provided complementary high-frequency surface information with reduced acquisition and processing times. To overcome RTI low-frequency distortions, a revised normal integration strategy was implemented using surface planarization and frequency-domain fusion with photogrammetric data based on Power Spectral Density analysis. The resulting hybrid models combine metric reliability with enhanced surface detail, providing a scalable and non-invasive approach for papyrological documentation and conservation research. Full article