Search Results (846)

Metal anodes offer substantially higher specific and volumetric capacities than conventional anode materials such as graphite in lithium-ion batteries or hard carbon in sodium-ion batteries. However, the integration of metal anodes into solid-state batteries poses significant challenges, particularly with respect to processing, interfacial stability, and cell assembly. Anode-free solid-state batteries (AFSSBs) address these challenges by eliminating the pre-installed metal anode, instead forming the metal in situ during the initial charging (formation) step. In anode-free solid-state batteries, the quality of the interfacial contact is particularly critical, as insufficient contact can lead to locally increased current densities. Consequently, the initial metal plating during the formation step plays a decisive role in determining the homogeneity and stability of the anode interface. Furthermore, conventional battery-grade copper foils (~10 µm) are considerably thicker than required for the targeted C-rates and are difficult to use as stand-alone anode-free current collectors, thereby hindering the industrial production of anode-free solid-state batteries. In this publication, we demonstrate the application of atmospheric plasma spraying (APS) to fabricate thin copper current collectors directly on the ceramic solid electrolytes LAGP (lithium aluminium germanium phosphate) and BASE (beta-alumina solid electrolyte) with superior interface contact. No mechanical damage or diffusion of copper into the solid electrolyte nor formation of secondary phases at the interfaces were observed in SEM or EDS despite the elevated process temperature. LAGP with a thickness as low as 300 µm was successfully coated and subsequently used for plating/stripping experiments. Finally, dense sodium metal was plated at the copper-substrate interface of a 1.4 mm thick BASE sample. Full article

Secondary caries and biofilm accumulation remain major causes of failure in provisional crowns and restorations, highlighting the need for multifunctional resin coatings with antibacterial and remineralizing capabilities. This study aimed to develop a novel bioactive and antibacterial resin-based surface coating incorporating 10% dimethylaminododecyl methacrylate (DMADDM), 20% nanoparticles of amorphous calcium phosphate (NACP), and/or 20% calcium fluoride nanoparticles (nCaF₂) within a urethane dimethacrylate/triethylene glycol divinylbenzyl ether (UDMA/TEG-DVBE) matrix. Coatings were evaluated for degree of conversion (DC), flow, shear bond strength, brushing wear resistance (10,000 cycles), and calcium (Ca), phosphate (PO₄), and fluoride (F) ion release up to 70 days. All groups achieved clinically acceptable polymerization, with the lowest DC at 50%. NACP-containing coatings significantly increased shear bond strength to 18.3 ± 2.8 MPa, representing a ~170% increase compared with the experimental control (6.8 ± 2.1 MPa) and exceeding the ISO 10477 minimum threshold of 5 MPa. After brushing simulation, experimental coatings demonstrated low wear depth (0.93–1.19 µm), which was ~40% lower than the commercial control (1.85 ± 0.40 µm). Sustained ion release was achieved for 70 days, with 20% NACP-formula releasing 1.22 mmol/L Ca and 0.90 mmol/L PO₄, while the dual NACP–nCaF₂ formulation provided simultaneous Ca (0.62 mmol/L) and F (0.33 mmol/L) release. The developed coatings demonstrated promising physicochemical properties, bonding performance, wear resistance, and sustained remineralizing ion release, supporting their potential application as therapeutic surface coatings for provisional restorations. Full article

Diagnosis and monitoring of type 2 diabetes mellitus (T2DM) typically rely on invasive blood-based biomarkers. To explore non-invasive alternatives, this study examined tongue coating metabolites to identify metabolic signatures linked to diabetes progression. A case-control observational study categorized participants into control, prediabetes, and diabetes groups. Tongue coating samples were analyzed using liquid chromatography-mass spectrometry (LC-MS). Differential metabolites were correlated with clinical parameters, including HbA1c, BMI, and eGFR. Distinct metabolic profiles emerged across groups, with significant differences in five endogenous metabolites (phenylpyruvic acid, propionylcarnitine, pyridoxal 5′-phosphate, phenethylamine, phenethylamine glucuronide) and four amino acids (isoleucine, lysine, phenylalanine, tyrosine). Diabetic subjects showed elevated phenylpyruvic acid and phenethylamine, while propionylcarnitine, pyridoxal 5′-phosphate, and phenethylamine glucuronide were reduced. Phenethylamine was positively correlated with HbA1c; propionylcarnitine and phenethylamine glucuronide showed negative correlations with HbA1c and BMI. Detected total amino acids were inversely correlated with eGFR. Additionally, a diabetes index derived from these metabolic features also holds potential for discriminating disease states. These findings underscore the potential of tongue coating metabolites as a relatively non-invasive approach for evaluating T2DM states. The observed metabolic alterations provide valuable insights into diabetes-associated dysregulation, including protein glycation, obesity-related metabolic shifts, and renal impairment. Full article

To develop a high-performance inorganic fireproof coating suitable for steel structures, this study utilized magnesium phosphate cement (MPC) as the matrix and introduced expanded perlite (EP) as a lightweight aggregate. The effects of EP content (40–55%) and magnesium-to-phosphorus ratio (M/P = 4:1–7:1) on the dry density, compressive strength, bond strength, and fire resistance of the coating were systematically investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) were employed to reveal the phase evolution and microstructure evolution mechanisms at high temperatures. The results indicate that increasing EP content significantly reduces the dry density and thermal conductivity of the coating, enhancing thermal insulation performance. However, excessive incorporation leads to the deterioration of mechanical properties, with an optimal EP content of 45%. The M/P ratio influences the interfacial bond strength and high-temperature structural stability by regulating the proportion of the hydration product K-struvite (KMgPO₄·6H₂O) and residual MgO. Compressive strength peaked at M/P = 6:1 (0.80 MPa), while bond strength was optimal at M/P = 5:1 (0.097 MPa), corresponding to the best fire resistance (back-side temperature of 180.4 °C). At high temperatures, K-struvite dehydrates and transforms into anhydrous KMgPO₄, which, together with residual MgO and crystallized SiO₂ from EP, forms a dense ceramic skeleton, ensuring the structural integrity of the coating. Comprehensive performance evaluation determined the optimal mix ratio as M/P = 5:1 and EP content = 45%. The coating with this ratio exhibits a dry density of approximately 560 kg/m³, a 14-day compressive strength of 0.53 MPa, a bond strength of 0.097 MPa, and a back-side temperature of 180.4 °C under flame exposure, demonstrating a favorable balance of lightweight character, mechanical integrity, and thermal insulation performance suitable for steel structure fire protection applications. Full article

The plasma electrolytic oxidation (PEO) of Zirlo alloy was carried out in a phosphate electrolyte with CaNa₂(EDTA) as an additive (0–15 g/L) to improve its corrosion and wear resistance. The PEO behavior, microstructure, phase composition, and performance of coatings were characterized as a function of the concentration of the additive. The results indicate that the addition of CaNa₂(EDTA) promotes coating growth and improves the coating structure and phase composition. When the additive concentration is 5–10 g/L, the coating shows an improved thickness, and denser microstructure. The coatings consist of m-ZrO₂ and t-ZrO₂ as the main crystalline phases, as well as amorphous materials with Ca and P. The t-ZrO₂ phase content rises sharply when CaNa₂(EDTA) is added into the electrolyte (81.3% t-ZrO₂ is obtained under the condition with 10 g/L CaNa₂(EDTA)). Potentiodynamic polarization tests demonstrate that PEO treatment significantly enhances the corrosion resistance of Zirlo alloy. Under the condition of 5 g/L CaNa₂(EDTA), the corrosion current density of the coating decreases by two orders of magnitude compared to the substrate, achieving the best corrosion resistance. Friction and wear tests also show that the coating obtained at 5 g/L CaNa₂(EDTA) exhibits the shallowest wear scar and the lowest wear rate, demonstrating optimal wear resistance. This study shows the novelty of obtaining high-quality PEO coatings on Zirlo alloy based on Ca and P incorporation. Full article

Titanium alloys, particularly β-type Ti-13Nb-13Zr, are promising biomedical materials due to their low elastic modulus and excellent biocompatibility. However, their bioactivity needs improvement for better bone integration. In this study, a calcium-phosphate (Ca/P) coating was prepared on a Ti-13Nb-13Zr alloy via micro-arc oxidation (MAO) in an electrolyte containing calcium acetate and dipotassium hydrogen phosphate. The effect of applied voltage (300 V, 400 V, and 500 V) on the phase composition, surface morphology, and in vitro bioactivity of the coatings was investigated. Surface characterization was performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive spectroscopy (EDS). The results show that increasing the voltage increased the surface roughness, average pore size, and rutile TiO₂ content in the coating. The Ca/P ratio in the coating approached 1.67 at 500 V, similar to that of natural bone. After immersion in simulated body fluid (SBF) for 20 days, the coating formed at 500 V induced the highest deposition of hydroxyapatite (HA), completely covering the microporous surface. These findings indicate that MAO treatment at 500 V significantly enhances the bioactivity of the Ti-13Nb-13Zr alloy, making it a promising candidate for orthopedic implants. Full article

Organic coatings are used as one of the most effective strategies for the corrosion protection of metals. Nowadays, due to environmental regulations, the use of water-based coatings has become essential compared to solvent-based ones. However, their application to magnesium alloys remains largely unexplored due to their high reactivity with water. In the present work, a phosphate-functionalized waterborne binder is applied to AZ31B magnesium alloy. The surface has been modified by four different pre-treatments, respectively: (i) mechanical grinding, (ii) pickling, (iii) conventional conversion treatment, and (iv) a novel conversion treatment based on layered double hydroxides (LDH). The most promising pre-treatments are selected to explore their synergy with a biobased waterborne binder, containing CeO₂ nanoparticles as a corrosion inhibitor. The morphology and composition of the different systems are studied, prior to and after corrosion tests in NaCl solution, by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Results obtained by electrochemical impedance spectroscopy (EIS) in NaCl solution have revealed not only that LDH performs better than the conventional conversion treatment but also the synergy between LDH pre-treatment and CeO₂ nanoparticles when two organic layers are used. Full article

Surface damage occurring during surgery can compromise coating integrity, leaving exposed areas susceptible to bacterial colonization. However, the impact of partial coating loss on antibacterial performance has not yet been investigated. In this work, a multifunctional UV-activated coating composed of hydroxyapatite, magnesium phosphate, and zinc oxide (HMZ) was developed and electrodeposited onto AZ31 and MgCa magnesium alloys. Its antibacterial efficacy against Staphylococcus aureus and Escherichia coli was evaluated under three conditions: adhered bacteria, planktonic cells, and biofilm. In the absence of UV activation, coated surfaces exhibited no significant antibacterial activity. In contrast, fully coated and UV-activated surfaces achieved bacterial reductions above 98% in all scenarios. Surfaces with 60% coverage showed antibacterial efficacy equivalent to that of fully coated surfaces, even against established biofilm. Surfaces with 30% coverage also exhibited moderate activity, particularly against adhered and planktonic bacteria. These results demonstrate that full surface coverage is not required to preserve the coating’s antibacterial effectiveness. This strategy provides a clinically relevant solution to maintain antibacterial protection even when coating integrity is compromised. Full article

Inorganic magnesium potassium phosphate (MKP) coatings offer rapid, zero-volatile organic compound (VOC) corrosion protection for steel structures. However, their application is impeded by insufficient mechanical strength and limited barrier durability. This study integrates calcium sulfate whiskers (CSWs) into a sprayable MKP matrix. Unlike conventional polymeric or metallic fibers, CSWs demonstrate excellent chemical compatibility with the MKP matrix, enabling a dual-enhancement mechanism. The optimal formulation, containing 15 wt.% CSWs, boosts the 28-day compressive strength by 35% and the bond strength by 39%. Electrochemical analysis shows a 93.6% increase in coating resistance (R_f), indicating an improved physical barrier against corrosive species, along with a 52% reduction in corrosion current density. These improvements result from fiber bridging and a dissolution–reprecipitation process that densifies the whisker–matrix interface. Nevertheless, an excessive amount of CSW (20 wt.%) disrupts the matrix continuity and reduces performance. This work presents a high-strength, zero-VOC, spray-applied coating with a novel dual-enhancement mechanism for durable steel protection in aggressive environments. Full article

The occurrence of contact lens complications caused by inadequate cleaning of the lenses using “All-in-One” contact lens cleaning solutions (CLCSs) represents a medically relevant problem worldwide. This study explores the potential of cold atmospheric plasma (CAP) to enhance the efficacy of CLCSs and address complications from inadequate lens hygiene. It was examined whether exposure to CAP for 1–24 h could boost the antibacterial effects of CLCSs and other solutions, including Milli-Q water (M-QW), physiological saline (NaCl), and Dulbecco’s Phosphate Buffered Saline (DPBS). Additionally, the stability of reactive oxygen and nitrogen species (RONS) and their impact on pH immediately after treatment and over 1–4 weeks was assessed. Furthermore, the cleaning efficacy of plasma-activated solutions (PASs) was tested on lipid-coated silicone hydrogel lenses. Results showed that CAP increased RONS concentrations immediately, with elevated levels persisting over time. While no significant improved antibacterial effect was observed against Escherichia coli in CLCSs, CAP treatment generated disinfectant properties in M-QW and NaCl solutions. Importantly, CAP-treated CLCSs significantly improved the cleaning performance on lipid-coated lenses, though M-QW’s cleaning ability worsened post-treatment. pH measurements indicated notable decreases in M-QW and NaCl after CAP, whereas buffered solutions like CLCSs and DPBS remained stable. Overall, CAP demonstrates promise for contact lens disinfection and surface modification; however, further research and pre-clinical trials are necessary before clinical application in ophthalmology. Full article

To tackle the long-standing issue of inadequate corrosion protection in waterborne coatings, this study innovatively incorporates hollow glass microspheres (HGB) into waterborne epoxy zinc-rich primers through physical blending, constructing a dual-layer synergistic anticorrosion system comprising an HGB-modified primer and a zirconium phosphate/urushiol titanium polymer (UTPCZrP)-modified waterborne epoxy topcoat. Optimal performance is achieved with 2 wt% HGB addition: the dual-layer coating retains favorable physicochemical and mechanical properties while enhancing anticorrosion performance by 1–2 orders of magnitude, boasting an impedance of 3.2 × 10⁶ Ω, a corrosion rate as low as 5.71 × 10^–6 mm/year, 99.98% protection efficiency (stable after 25-day immersion), and 720 h salt spray resistance without corrosion diffusion. This method exhibits universality in waterborne polyurethane (WPU) and polyester (WPE) systems, yielding impedance values of 3.57 × 10⁶ Ω and 2.7 × 10⁶ Ω, respectively, with over 90% improved anticorrosion performance and long-term stability. By optimizing components and synergistic system design, this work significantly enhances waterborne coatings’ anticorrosion efficiency, reduces raw material costs, and provides a scalable technical pathway for high-performance, eco-friendly anticorrosion coatings. Full article

Electroless Ni–P coatings are widely used for corrosion and wear protection, yet their ability to deliver water-based superlubricity and the role of phosphorus content remain insufficiently understood. Here, electroless Ni–P coatings with four P contents (3.4, 6.4, 9.0, and 12.4 wt%) were deposited on GCr15 steel with nearly constant thickness and comparable initial roughness, and were tested against Si₃N₄ balls in neutral 0.5 M NaH₂PO₂ solution. Friction measurements, together with surface topography characterization and tribofilm analysis, were used to link P content with tribofilm chemistry and superlubricity. All coatings achieved macroscale superlubricity, exhibiting steady-state friction coefficients below 0.01, while the running-in time decreased markedly as P content increased. During sliding, the wear tracks underwent mechano-chemical polishing to Sa ≈ 11–12 nm and formed phosphate–silicate tribofilms enriched in P–O and Si–O species on both the coating and the counterface. These findings establish a composition–tribofilm–superlubricity relationship in the Ni–P/NaH₂PO₂ system and demonstrate that P-content optimization is an effective internal design lever to accelerate running-in, mitigate wear, and achieve robust superlubricity under neutral aqueous lubrication. Full article

Phosphate coatings were obtained by cold method from solutions based on Mazev Salt (containing Mn(H₂PO₄)₂∙2H₂O and iron phosphates). Metal nitrates and nitrites were introduced into solutions as accelerators of the phosphating process. To obtain green and blue phosphate coatings, procyon olive green and methylene blue dyes (8 g/L) were added into the solutions. Colored phosphate coatings are deposited unevenly on the steel surface. The thickness of the modified phosphate films was estimated from SEM images of the cross-section samples and determined to be 3–4 microns. Colored phosphate coatings are fine-grained with a grain size of 170–190 nm, which was determined using an atomic force microscope. Phosphate films continue to exhibit protective properties when heated to 100 °C. With a further increase in temperature, the protective ability of the film is significantly reduced. Colored phosphate films have a low coefficient of friction (0.1–0.15). The breakdown voltage of colored phosphate coatings is 180–200 V, which characterizes low electrical insulation ability. Based on the established properties, colored phosphate coatings can be used as protective and decorative. Full article

Surface roughness is a quality-critical attribute in industrial zinc phosphating, directly affecting sealing performance, coating uniformity, dimensional tolerances, and first-pass production yield in automotive pretreatment lines. While the chemical mechanisms of phosphate coating formation are well understood, the translation of this knowledge into statistically defensible, production-scale prioritization of bath chemistry control levers under real manufacturing constraints remains limited, particularly with respect to surface roughness stability and its environmental implications. This study investigates surface roughness control in a fully operational industrial zinc phosphating line by systematically evaluating the effects of pickling acid chemistry (H₂SO₄ versus H₃PO₄), dissolved ferrous iron (Fe²⁺) levels in pickling and phosphating baths, and nitrate accelerator dosage. A Taguchi L16 (2⁴) experimental design was implemented under real manufacturing constraints. Surface roughness (Rz) was measured in accordance with ISO 4287 and analyzed using a general linear model supported by partial effect size estimation (ηp²) and bootstrap confidence intervals. This approach enables statistically robust ranking of dominant and secondary control parameters, rather than qualitative trend confirmation alone. The robustness of statistically identified trends was independently verified using paired measurements from 25 production components, while scanning electron microscopy provided qualitative mechanistic support. The results demonstrate that pickling acid chemistry and nitrate accelerator dosage are the dominant control parameters governing surface roughness stability, whereas Fe²⁺ concentration does not act as a primary independent driver within the defined Fe²⁺ concentration ranges investigated in this study, but contributes through interaction-dependent mechanisms. Phosphoric acid pickling combined with nitrate acceleration consistently yields lower and more stable roughness values. In addition, roughness-related nonconformities were translated into product carbon footprint outcomes using an ISO 14067–aligned, gate-to-gate framework with Monte Carlo uncertainty analysis, explicitly quantifying the carbon footprint penalties associated with quality-driven rework and external return logistics under industrial production conditions. Full article

To enhance the wear and corrosion resistance of Zr alloy components in marine engineering, this study investigated the influence of the applied voltage (ranging from 470 to 620 V) on the morphology, structure, and properties of ceramic coatings formed on a Zr alloy substrate by Micro-arc Oxidation (MAO) in a silicate–phosphate composite electrolyte. The results showed that with increasing voltage, the coating thickness increased (from 15.12 to 52.80 μm) and the surface roughness increased (from 1.12 to 4.89 μm), while both the surface and cross-sectional porosity first increased and then reached their minimum values at 620 V (1.61% and 5.75%, respectively). Phase analyses indicated that the coatings consisted mainly of monoclinic ZrO₂ (m-ZrO₂), along with minor amounts of SiO₂, ZrSiO₄, and Zr₃(PO₄)₄. The coating prepared at 620 V exhibited optimal performance: its hardness was 1.98 times that of the substrate, the wear volume decreased by approximately 87%, the self-corrosion potential shifted positively by 539 mV, the corrosion current density decreased by nearly two orders of magnitude, and the polarization resistance increased by approximately two orders of magnitude. These results demonstrate a substantial improvement in the service performance of Zr alloys for marine applications. Full article