Search Results (6,166)

In roll-to-roll slot-die coating systems, backup roll eccentricity induces periodic fluctuations in key process parameters, leading to coating defects. Therefore, accurate prediction of backup roll eccentricity during operation is essential for maintaining stable coating quality. However, conventional methods based on web tension signals have limitations in clearly distinguishing and quantitatively evaluating subtle eccentricities. To address this issue, this study proposes a data-driven framework for predicting backup roll eccentricity using meniscus image information. Representative morphological features are defined to describe the global shape, local shape, and curvature characteristics of the meniscus. Since these features are sensitive to eccentricity-induced process variations, they can serve as effective indicators for eccentricity prediction. The defined features are used to train regression models, and the model with the highest predictive accuracy is selected. Experimental results confirm that the proposed meniscus-based approach significantly outperforms conventional tension-based methods. The proposed method achieves an average Root Mean Square Error (RMSE) of approximately 0.63 μm, an average Normalized Root Mean Square Error (NRMSE) of approximately 0.34, and a coefficient of determination (R²) greater than 0.93 across all test cases. These results demonstrate the feasibility of robust process monitoring using a simple vision sensor configuration. Full article

The persistence of antibiotics like ciprofloxacin (CIP) in aquatic environments necessitates the development of efficient, low-cost wastewater treatment technologies. This study investigates a low-temperature fabrication strategy for mixed-phase copper oxide (CuO/Cu₂O) coatings synthesized via co-precipitation and immobilized using electrophoretic deposition (EPD). A critical finding was that a 25 min precursor aging time (T25) preserved a metastable mixture of CuO and Cu₂O phases, which is highly advantageous for creating heterojunction interfaces that enhance charge separation. In contrast, extended aging (T35) promoted phase consolidation toward bulk CuO, reducing catalytic surface area. During the EPD process, applied voltage acted as an influence to the relative phase composition and deposition behavior of the deposited coatings; 1.0 V was identified as the optimal condition, balancing high phase fidelity with enhanced crystallinity (average crystallite size of 30.6 nm) and mechanical stability. Photocatalytic experiments demonstrated significant CIP degradation, with the 0.9 V and 1.0 V films outperforming the 1.2 V film, possibly due to more favorable surface chemistry and phase diversity. While the 0.9 V film achieved the highest mineralization efficiency (18% TOC removal), the 1.0 V film offered the best balance between photocatalytic activity, structural stability, and phase selectivity for practical applications. High-Performance Liquid Chromatography-Mass Spectrometry HPLC-MS analysis suggested that degradation proceeds through oxidative pathways involving piperazine ring cleavage and defluorination. Full article

Low-emissivity (low-E) coatings are among the most effective thin-film technologies for reducing radiative heat losses and controlling solar heat gain in buildings, which account for approximately 30–40% of global primary energy consumption. This expanded review follows the technological evolution of low-E glazing from early transparent-conductor “heat mirrors” to modern multi-silver dielectric/metal/dielectric (D/M/D) architectures and emerging functional coatings. Four complementary perspectives are addressed: (i) the materials employed, from silver-based multilayers and transparent conducting oxides (ITO, FTO, AZO, GZO) to seed, blocker, and protective dielectric layers; (ii) the deposition systems, contrasting on-line pyrolytic/CVD “hard” coatings with off-line magnetron-sputtered “soft” coatings, together with ALD, sol–gel, and evaporation routes; (iii) the methods of analysis used to correlate microstructure, composition. and interfaces with optical, electrical, and thermal behaviour (XRD, XRR, SEM/TEM, AFM, XPS, SIMS, spectrophotometry, ellipsometry, emissivity, and U-value metrology according to EN 410/EN 673 and ISO 9050); and (iv) the functional performance of low-E stacks in insulating glass units, vacuum glazing, retrofit films, and smart-window systems across climate zones. Persistent research gaps are identified in long-term durability and ageing, indium-free scalable materials, standardized accelerated testing, and multi-objective design of thinner, more selective, and more robust stacks. Full article

Copper and its alloys are indispensable for electronics, communications, new energy systems, and aerospace engineering due to their exceptional electrical conductivity and mechanical properties. However, the thin cuprous oxide (Cu₂O) layer that naturally forms on copper and its alloys is prone to failure under elevated temperatures and high humidity, particularly in chloride-rich environments, leading to accelerated localized corrosion. While conventional chromate-based passivation has long been the industrial standard for preventing corrosion, its use has been increasingly restricted by global regulations (such as RoHS and REACH) due to its severe toxicity and health risks. To address the conflict between environmental compliance and protective performance, this review systematically evaluates recent advances in environmentally friendly, chromium-free anti-corrosion coatings in the present review. These alternative coatings are critically analyzed and categorized into four mechanistic groups: (i) inorganic conversion coatings (including molybdate, tungstate, rare earth, and phosphate systems); (ii) organic films formed via chemical or physical adsorption (such as organic inhibitors, thiol-based monolayers, and organosilane self-assembled films); (iii) conversion coatings engineered through covalent bonding, coordination chemistry, and microstructural tailoring; and (iv) multifunctional coatings that integrate self-healing capability with high electrical conductivity. Beyond providing a technical summary, this review explored how the swift progression of electronic information technology, new energy infrastructure, and robotics has imposed more exacting, multifunctional demands on copper components. This review provides a strategic roadmap for future research and prioritizes the creation of protection strategies that operate robustly in multi-physics coupling environments—integrating high conductivity, autonomous self-healing, and long-term chemical stability to ensure the reliability of next-generation infrastructure. Full article

Polyetheretherketone (PEEK) is increasingly attractive for patient-specific maxillofacial reconstruction because its elastic modulus approximates cortical bone, it is fully radiolucent, and it is compatible with additive manufacturing; its principal limitation is bioinertness, as the hydrophobic surface does not support protein adsorption or direct bone apposition. This study aimed to functionalize the surface of fused-deposition-modeling (FDM)-printed, medical-grade PEEK to increase its potential for bioactivity while preserving these bulk advantages. To this end, 3D-printed specimens of implant-grade PEEK were activated by CO₂ plasma and coated with gelatin methacryloyl (GelMA) via EDC/NHS coupling followed by UV photocrosslinking. Surfaces were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, sessile-drop water contact angle measurement, gravimetric analysis, and scanning electron microscopy (SEM). Plasma treatment introduced oxygen-containing functional groups and reduced the water contact angle from 78.3° to 6.6°. GelMA deposition following EDC/NHS coupling, consistent with covalent immobilization, was supported by characteristic amide bands and was most pronounced for the 50 mg/mL formulation, corresponding to a deposited mass of 11.81 ± 0.47 μg/mm²; SEM revealed a relatively uniform protein film along the printed filaments. These results establish a surface-functionalization route and provide preliminary physicochemical indicators of potential bioactivity for patient-specific PEEK implants, to be confirmed through in vitro and in vivo biological validation. Full article

This study focuses on the deposition of nickel thin-films onto glass fiber fabric via DC magnetron sputtering and explores their potential for broadband microwave absorption applications. A total of twelve laminate samples were prepared by integrating the coated fabrics with epoxy resin, with sputtering powers ranging from 0.5 to 2 kW and deposition times ranging from 10 to 90 min. The microstructure, surface resistance, electromagnetic parameters, and microwave absorption performance were systematically characterized using SEM, XRD, four-point probe measurements, and vector network analysis, supplemented by the Lorentz model fitting and simulation validation. The results indicate that the nickel coatings exhibit a non-uniform arc-like morphology, with preferential growth along the (111) crystallographic plane, while the (200) and (220) planes form under specific conditions. The surface resistance reaches up to 10⁸ Ω·m, suggesting the absence of a continuous conductive network. Electromagnetic parameter analysis reveals that the laminates display dielectric-loss-dominated microwave absorption, and the Lorentz fitting identifies double resonance peaks under prolonged or high-power sputtering. The addition of a dielectric matching layer further enhances the absorption performance. All samples achieve wideband absorption within the Ku-band. Notably, the samples prepared at 1 kW for 30 min and at 1 kW for 90 min both exhibit a reflectivity of ≤−10 dB across the entire 8–18 GHz frequency range. The experimental results are in good agreement with simulations. The bulk density of the laminates is approximately 1.8 g/cm³. These findings confirm that magnetron-sputtered nickel-coated continuous glass fiber fabrics hold considerable promise for wideband microwave absorption applications. Full article

Stable emulsified oil droplets are difficult to separate because of persistent interfacial films and colloidal stability. Garlic-extract-functionalized Fe₃O₄ magnetic colloids, operationally denoted Allicin@Fe₃O₄, were prepared by in situ coprecipitation as organic–inorganic building blocks for gel-like interfacial capture. The sample name identifies the allicin-containing garlic-extract route and does not imply that allicin was proven to be the predominant surface species. SEM, FTIR, and XRD supported deposition of an organic, sulfur/oxygen-containing surface layer and retention of crystalline Fe₃O₄, but these methods are not species-specific. The colloids removed more than 95% of emulsified oil within 20 min and reached an experimental equilibrium apparent uptake of approximately 380 mg·g⁻¹. Tests across pH 3–11, 0–50 g·L⁻¹ NaCl, 15–55 °C, and representative coexisting ions showed robust but condition-dependent removal. Removal remained above 90% after five reuse cycles and was approximately 84% after ten cycles. Calculations using allicin as a representative garlic organosulfur molecule suggest how polar sulfur/oxygen regions and allyl segments could favor oil–droplet anchoring and association; they do not establish the surface composition of the extract-derived coating. The capture behavior is consistent with transient, gel-like particle–droplet association coupled to magnetic recovery. These results connect bio-derived surface functionalization, gel-related colloidal structuring, and magnetic separation under the tested batch conditions. Full article

Fresh-peeled garlic cloves are a very convenient ready-to-cook product; however, their high perishability requires packaging systems that maintain the quality of the garlic while addressing the need for more sustainable materials. This study evaluated the quality evolution of peeled garlic cloves during refrigerated storage (5 °C) in microperforated modified atmosphere packaging (MAP) systems consisting of trays sealed with egg white protein (EWP)-based films, either uncoated (EWP-U) or coated with beeswax (EWP-BW). Their performance was compared with commercial polylactic acid (PLA) and oriented polypropylene (OPP) films. The EWP-based packages generated an internal atmosphere of approximately 7% O₂ and 15% CO₂, under which peeled garlic cloves showed delayed fungal decay, reduced yeast and mold growth, and mitigated surface discoloration compared with other packaging systems, whose atmospheres remained closer to air. However, weight loss was promoted in the garlic cloves packaged with EWP-U films. The hydrophobic coating applied in EWP-BW films improved the water vapor barrier properties compared with EWP films, thus reducing the weight loss observed in the garlic cloves, but increasing fungal decay. These results suggest that an optimized packaging system should combine the lower water vapor transmission rate provided by EWP-BW films with the internal gas composition achieved in EWP-U packages. Accordingly, EWP-BW films represent a promising bio-based alternative for preserving the quality of peeled garlic cloves, provided that the effective O₂ and CO₂ transmission rates through the package are appropriately adjusted to generate a more favorable modified atmosphere. Full article

Atmospheric carbon dioxide (CO₂) has reached an unprecedented 430 ppm, warming the planet by 50% compared with pre-industrial times and prompting a search for a quick and effective solution to control CO₂ emissions. As a robust, renewable, biodegradable, and sustainable material, nanocellulose can serve as a strong support for many active molecules. Nanocellulose, whether in suspension, aerogel, or membrane form, is not sufficient for efficient CO₂ capture and separation; hence, active molecules, such as silanes, amines, zeolites, and metal–organic frameworks (MOFs), are introduced via chemical modification, such as grafting, or via physical mixing as fillers or additives to make nanocellulose effective for CO₂ capture and separation. Introducing amine or silane molecules into nanocellulose has proven to be an effective strategy for achieving a satisfactory CO₂ absorption capacity exceeding 6 mmol/g. Nanocellulose membranes, when fabricated with MOFs or zeolites and used as a coating with polyvinyl alcohol (PVA) to create a thin-film composite membrane (TFC), can achieve CO₂ permeance of more than 600 GPU for CO₂ separation from flue gas, with CO₂/N₂ selectivity close to 40. This review provides an overview of nanocellulose-based CO₂ capture and separation materials developed over the last 10 years, along with the related challenges that must be overcome to meet current performance and demand. To facilitate readability, the author has provided a brief introduction to the origin, performance, and scale-up developments of nanocellulose at the start of this review. Full article

Centrifugal atomization is used to generate droplets or particles in processes ranging from crop protection and metallurgical powder production to rotary-bell coating, combustion, and spray-based product processing. However, comparison across studies is hindered by differences in atomizer geometry, characteristic scales, fluid properties, operating windows, diagnostic methods, and performance metrics. This article presents a structured critical review of centrifugal atomization mechanisms, investigation methods, and multidisciplinary applications. The literature is organized according to operational definitions, atomizer configuration, liquid-film evolution, primary and secondary breakup, experimental and numerical approaches, and application-level performance. Rather than assuming universal phase boundaries, the review synthesizes reported transition criteria for direct-drop, ligament, and film breakup and examines their dependence on geometry, liquid throughput, rotational speed, fluid rheology, surface tension, and surrounding-gas conditions. Across applications, the available evidence indicates that rotational speed and liquid throughput strongly affect film thickness and breakup intensity, but their influence on droplet or particle size remains conditional on the prevailing regime and device geometry. The review further compares the strengths, limitations, validation status, and transferability of commonly used experimental and computational methods. Remaining priorities include standardized definitions of characteristic scales, matched-condition comparisons, uncertainty reporting, benchmark datasets for multiphysics models, and testable criteria for scale-up and cross-application transfer. Full article

Quercetin is a plant-derived flavonol positioned at the interface of metabolic health and food preservation. This review integrates quercetin chemistry, plant biosynthesis and metabolism, production-relevant extraction and microbial synthesis, bioavailability, mechanisms of action, preclinical and clinical evidence in metabolic syndrome (MetS), and applications in clean-label food preservation. Experimental studies indicate that quercetin modulates obesity-associated inflammation, dyslipidemia, hepatic steatosis, insulin resistance, hypertension, endothelial dysfunction, and gut-barrier impairment through interconnected Nrf2/HO-1, NF-κB/NLRP3, AMPK/SIRT1, PI3K/Akt, eNOS/NO, lipid metabolism, and microbiota-related pathways. Human evidence is narrower and heterogeneous: modest reductions in systolic blood pressure constitute the most consistent signal, whereas effects on fasting glucose, lipids, inflammatory markers, endothelial function, liver fat, and body weight vary by population, formulation, dose, and duration. In food systems, quercetin has been investigated as an antioxidant, antimicrobial, antibiofilm agent, and photodynamic photosensitizer. It is incorporated into edible films, coatings, freshness indicators, and controlled-release packaging, although most evidence remains laboratory-scale. Key translational challenges include limited aqueous solubility, variable bioavailability, incomplete long-term safety evidence, matrix-dependent efficacy, sensory constraints, manufacturing scale-up, migration, and regulation. Overall, quercetin is promising, but clinical use and industrial deployment require formulation-specific, adequately powered human studies and validation in clinically relevant populations and under commercially realistic processing conditions. Full article

The rapid development of implantable medical electronics requires robust biocompatible coatings capable of ensuring long-term stability in aggressive physiological environments. Although Grade 1 titanium is widely used for its excellent mechanical properties and corrosion resistance, active implants require defect-free insulating coatings to prevent electrical leakage and metal ion release. This study presents a systematic evaluation of Parylene C (P-C) thin films deposited by the Gorham chemical vapor deposition (CVD) process onto implant-grade titanium substrates. Four coating thicknesses (1, 5, 10, and 20 µm) were deposited and characterized using complementary chemical, morphological, optical, and mechanical techniques. Contact-angle measurements confirmed uniform hydrophobicity (90.56 ± 1.86°), while FTIR and EDX verified the characteristic chemical composition of P-C. Reflectometry, ellipsometry, and interferometry demonstrated excellent thickness control and deposition reproducibility. Pull-off testing showed high initial mechanical integrity, with detachment forces ranging from 52 to 73 N. However, accelerated PBS ageing (21 days at 90 °C) induced significant degradation, particularly for thicker coatings, reducing pull-off forces to 19–42 N. Likewise, thermal-shock cycling (−80 °C to +220 °C) caused severe interfacial damage, decreasing the required detachment force to approximately 5.5 N for 20 µm coatings because of extensive cracking and delamination. These results demonstrate that Parylene C provides excellent conformal coverage and chemical stability on titanium but that its durability is significantly affected by prolonged hydrothermal ageing and extreme thermal loading. This study provides practical guidelines for the design of reliable encapsulation systems for active implantable medical devices and highlights the need for improved interfacial engineering through optimized adhesion-promoting layers or hybrid protective architectures. Full article

In this study, a two-step electrodeposition strategy was proposed to fabricate an eco-friendly superhydrophobic polyaniline (PANI)/silane composite coating on mild steel for corrosion protection. The first step consists of creating a pure PANI adherent coating using a cyclic voltammetry technique and the second step consists of realizing superhydrophobic features using electrodeposition in mixed silane monomers at constant potential. The structure and composition characterization results revealed successful modification of the underlying pure PANI layer with superhydrophobic surface silane film. Wettability tests indicated a high contact angle of 155° and a low sliding angle of 4.2°. Electrochemical measurements revealed that the corrosion current density of PANI/silane-coated mild steel decreased by approximately three orders of magnitude compared to the uncoated sample and the corrosion protection efficiency was as high as 99.6%. Moreover, the prepared PANI/silane hybrid coating exhibited good chemical stability and strong adhesion after 10 days of corrosion in 3.5 wt.% NaCl solution. Full article

This study aimed to develop unique heat-resistant polymers with very high-intensity blue photoluminescence (PL), particularly by maximizing the PL efficiencies (Φ_PL) of fluorophore-incorporated polyimides (PIs) while maintaining their PL color. A bifunctional amide-linked fluorophore (HTA-BAPA) was synthesized from a hydrogenated trimellitic anhydride (HTA) derivative and 9,10-bis(4-aminophenyl)anthracene (BAPA) to covalently incorporate into the main chains of PIs. The dependence of the Φ_PL on the HTA-BAPA content was investigated using a wholly cycloaliphatic PI matrix, derived from 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) with 4,4′-methylenebis(cyclohexylamine) (MBCHA), without charge-transfer (CT) interactions, which mask the desired PL. The Φ_PL in the PI precursor film significantly decreased after thermal imidization while maintaining the PL spectral profile (spectral shape and position = PL color). This is likely related to low-level (two-molecular) fluorophore aggregation during thermal imidization, which is responsible for concentration quenching (CQ). Then, the effect of the chemical imidization process (Route-C) on Φ_PL was investigated. Route-C provided PI films via a simple solution coating and drying process without thermal imidization. However, when CBDA/MBCHA was used as the PI matrix, gelation/precipitation occurred during chemical imidization, which inhibited subsequent solution casting. To solve this problem, an alternative cycloaliphatic tetracarboxylic dianhydride, derived from the HTA derivative and 4,4′-biphenol (44′BP), was used to combine with 2,2′-bis(trifluoromethyl)benzidine. This matrix PI exhibited Route-C compatibility, excellent solubility, and high heat resistance (T_g = 263 °C), while maintaining a CT-inhibiting function. The PI cast film incorporating HTA-BAPA (2 mol%) exhibited a highly intense blue PL with an exceedingly high Φ_PL of 0.68 (68%) and a color coordinate, CIE (x = 0.151, y = 0.074), corresponding to deep-blue PL. The impact of casting solvent type on the Φ_PL was also investigated. A clear correlation between the boiling points (T_b) of the casting solvents and Φ_PL of the resulting PI cast films was observed, where Φ_PL monotonically increased with decreasing T_b. These results probably suggest that faster evaporation (solidification) related to the lower T_b during the first soft-drying step at 60 °C kinetically overcame the two-molecular fluorophore aggregation responsible for CQ. Solution casting from tetrahydrofuran (with the lowest T_b) afforded a maximum Φ_PL of 0.84 (84%). Thus, unique polymeric materials with excellent solubility, high T_g, relatively high thermal stability and acceptable film ductility along with highly intense pure-blue PL were obtained, broadening the scope of photoluminescent PI applications, such as heat-resistant fluorescent QR codes. Full article