Protective Layer Research Articles

Stabilizing zinc powder anodes via bifunctional MXene towards flexible zinc-ion batteries

Flexible zinc (Zn) batteries have gained considerable attention as wearable energy storage devices because of their inherent safety and high theoretical capacity. However, conventional Zn anodes suffer from dendrite growth, high rigidity, and poor cycling stability issues, hindering their practical application in flexible zinc-ion batteries. Herein, a dendrite-free and flexible Zn anode is designed using direct ink writing (DIW) printed MXene as a flexible and highly conductive current collector and MXene-wrapped Zn powder (ZnP) as the active material by carefully optimising the rheological properties of MXene-based dispersion. As a result, the synergistic effects of the MXene-based current collector and the MXene protective layer promoted dendrite-free Zn deposition and prevented side reactions, achieving an outstanding cycling performance that exceeded 130 h at a high depth of discharge of 30%. When paired with a Vanadium pentoxide (V2O5)-based cathode, the flexible full cell demonstrated stable electrochemical performance under mechanical deformation and can power electronic devices, presenting a promising pathway for the development of flexible zinc-ion batteries.

SHORT-ROOT specifically functions in the chalazal region to modulate assimilate partitioning into seeds.

Nourishing the embryo with endosperm and enclosing both embryo and endosperm in the seed coat are two important evolutionary innovations. Seed coat is conventionally viewed as a protective layer that functions after the seed has matured. Here, we challenge this notion by showing that a subregion of the seed coat, termed the chalazal seed coat (CZSC), is geared to gate seed nutrition loading in developing seeds. The CZSC develops the coordinative system comprising the apoplastic isolation, mediated by the restricted suberization, and the active transport, mediated by the specific expression of a variety of transporters, at as early as the globular embryo stage in both Arabidopsis and soybean seeds. This coordinated system in the CZSC disrupts the vascular continuum to the maternal tissues and forces the nutrient transport into selective and active absorption. We further reveal that the precision of the spatiotemporal suberin deposition and transporter expression is controlled by the regulatory hierarchy of SHR-MYBs cascades. Our results provide a mechanistic insight into the assimilate accumulation in dicot seeds.

Phase Engineering of ZnSe by Small Molecules as a High-Performance Protective Layer for Zn Anode.

The practical application of aqueous zinc ion batteries is still hampered by the side reactions and dendrite growth on Zn anode. Herein, the phase engineering of ZnSe coating layer by incorporating small molecules is developed to enhance the performance of Zn anode. The unique electronic structure of ZnSe⋅0.5N2H4 promises strong adsorption for Zn atoms and enhanced ability to inhibit hydrogen evolution, thereby promoting uniform Zn deposition and preventing by-product and dendrite growth. Meanwhile, fast Zn2+ transfer and deposition kinetics are also demonstrated by ZnSe⋅0.5N2H4. As a result, the ZnSe⋅0.5N2H4@Zn symmetric cell achieves long-term cycling stability up to 1900 h and 300 h at high current densities of 5 mA cm-2 and 20 mA cm-2, respectively. The assembled ZnSe⋅0.5N2H4@Zn||NH4V4O10 full cell presents outstanding cycling stability and rate capability. This work highlights the key role of crystal phase control of protective layer for high-performance zinc anode.

Inhibitory Potential of N-Methyl Formanilide on Mild Steel Corrosion in Sulfuric Acid: Quantum Chemical and Experimental Perspectives

Technological progress has led to increased use of metals and alloys such as aluminum, brass, bronze and mild steel. While mild steel is favoured for its availability, low cost and excellent mechanical properties, it is prone to corrosion. This study aims to reduce the corrosion of mild steel in sulfuric acid using N-methyl formanilide (NMF) as an inhibitor. The effectiveness of NMF was evaluated using gravimetric method (weight loss) and electrochemical impedance spectroscopy (EIS). Surface analyses were conducted using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The study examined the performance of NMF at different temperatures (298 K to 338 K) and varying inhibitor concentrations. The results indicated that the percentage inhibition efficiency (%IE) of NMF increased with higher concentration but decreased with temperature. The NMF formed a protective layer on mild steel through physical adsorption, which was confirmed by El-Awady adsorption isotherm and comparing it with other adsorption models. The kinetic and thermodynamic studies were also performed, with activation energy (Ea) and adsorption free energy (ΔG°ads) being calculated. These findings were further validated using the AM1 quantum mechanical method, revealing the promising results for the investigation.

Microporous Polyethylene and Cellulose Composite Separators for Reversible Lithium Electrode in Lithium Rechargeable Batteries

AbstractThe lithium metal anode is the best candidate for high energy density batteries because of its high specific capacity and low negative potential. Rechargeable lithium metal batteries (RLMB) have not yet been commercialized. The key factors that limit the practical use of RLMB are the formation and growth of lithium dendrites during the lithium deposition process and the reaction of the lithium anode with the organic solvent of the electrolyte, quantified by the Columbic efficiency (CE). To suppress the lithium dendrite formation and to improve CE, many approaches such as the formation of a protective layer on the lithium electrode and the use of additives to the electrolyte have been proposed. In this study, the effect of a thin cellulose film to improve CE of lithium deposition and stripping on the lithium electrode was examined. The cycle performance of a Li/Li symmetrical cell with a cellulose and polyethylene composite separator was examined for a carbonate electrolyte and an ether electrolyte. The improvements of CE were observed for both electrolytes with the cellulose film separator. The improvement could be explained by the good wettability of the cellulose film separator with the electrolyte.

Corrosion Inhibition and Adsorption Behaviour of Centrosema pubescens Leaf Extract for Copper in HCl Solution

Study’s Excerpt In this study, Centrosema pubescens leaf extract (CPE) has been confirmed as eco-friendly and efficient green inhibitor for copper corrosion in hydrochloric acid. Detailed thermodynamic analysis, revealed that CPE adsorption follows a Freundlich isotherm model. SEM-EDX and FTIR characterizations confirmed the formation of a protective layer confirming the potentials of the plant extracts in sustainable corrosion prevention. Full Abstract The anti-corrosion behaviour of Centrosema pubescens leaf extract (CPE) on copper in 1.5 M hydrochloric acid was investigated using weight loss method at different temperatures, followed with scanning electron microscopy (SEM) surface characterization connected with energy dispersive X-ray spectroscopy (EDX). The Fourier transform infrared spectrum of CPE was obtained. CPE inhibition effectiveness depends on the temperature and its concentration. CPE restrains the copper corrosion with 94.26 % inhibition efficiency at 1.0 g/L of CPE and at 303 K. For the CPE-inhibited system, a higher activation energy (Ea) value (range of 31.09 to 38.70 kJmol-1) compared to 20.34 kJmol-1 of the blank solution was obtained. The reaction process is spontaneous and endo thermic, as indicated by the ΔH, ΔS and ΔG values calculated. CPE adsorption behaviour fitted best into Freundlich isotherm.

Characterization of the chemical composition, amino acid, and fatty acid profiles of underutilized poultry feathers

Poultry is one of the leading subsectors of animal husbandry. However, despite its socioeconomic importance, it is considered a significant contributor to environmental problems through its waste production, including feathers. Feathers are protective layers that make up the typical outer wrapping. It can be found on feathery and in some non-feathery winged creatures. In this context, this research was conducted to determine the proximate, mineral, fatty acid, and amino acid profile in poultry feathers. The proximate analysis revealed the values of ash (1.40%), moisture (6.30%), crude fiber (9.20%), protein (67.50%), crude fat (2.90%), and carbohydrate (12.70%). The mineral elements (ppm) indicated sodium (0.04), magnesium (0.03), potassium (0.04), calcium (0.06), phosphorus (0.05), manganese (0.01), iron (0.01), and zinc (0.01). The amino acid profile showed that it contained sixteen amino acids which includes important amino acids most especially all the essential amino acids except lysine. In contrast, the fatty acid profile revealed that it contained twelve fatty acids. Among these, it includes basic saturated fatty acids such as glycine and rich in unsaturated fatty acid contents. The finding indicates that poultry feathers can contribute useful nutrients, mineral elements, fatty acids, and amino acids to livestock feed for maximum utilization and rapid development, making it a good potential and sustainable material from waste to wealth.

The Identification of Proteomic Signatures Associated with Alkaline Tolerance in the Skin Mucus of Crucian Carp (Carassius auratus).

The skin is covered by a protective mucus layer, which is essential to the innate defense mechanism of fish. Investigating the response of skin mucus to various toxic stresses is crucial for enhancing its ability to tackle environmental challenges and developing strategies to mitigate toxic effects. Alkalinity stress assays (50 mmol/L NaHCO3) were conducted on crucian carp (Carassius auratus) from Lake Dali Nur (pH = 9.6) and Ping Xiang red crucian carp from freshwater (pH = 7) over 7 days. The expression of skin mucous proteins was analyzed using the liquid chromatography (LC)-spectrometry (MS)/MS Analysis-Data-independent acquisition (DIA) mode. A total of 12,537 proteins were identified across 20 samples from four groups, with 12,025 quantified. In the alkaline water population, high alkali stress resulted in the up-regulation of 139 proteins and the down-regulation of 500 proteins. In contrast, the freshwater population showed an increase in 112 proteins and a decrease in 120; both populations had a total of 23 genes up-regulated and 21 down-regulated. The protein regulatory network for the alkaline water group included 3146 pairwise interactions among 464 nodes, with only 20 being differentially expressed proteins. Conversely, the freshwater group's network comprised just 1027 specific interactions across 337 nodes, with 6 corresponding to differentially expressed proteins. A common protein regulatory network responding to high alkali stress was extracted and visualized for both populations. Based on their regulatory relationships and expression levels, these proteins are hypothesized to play similar roles under high alkali stress. Notably, the alpha-globin fragment and keratin type I cytoskeletal 13-like proteins showed markedly up-regulated expression, with the alpha-globin fragment increasing nearly a thousandfold from an extremely low level. This suggests it could serve as a potential biomarker for alkali tolerance, warranting further investigation.

Corrosion studies of Al-Mg-Sc-Zr Alloy with Low Sc/Zr ratio fabricated by laser powder bed fusion for marine environments

This study investigates the corrosion behavior of a laser powder bed fusion (LPBF) Al-Mg-Sc-Zr alloy with a Sc/Zr ratio of less than 1 in 3.5wt% NaCl solution. X-ray diffraction (XRD) analysis revealed the presence of an Al matrix with face-centered cubic (FCC) structure and the secondary phase Al3(Sc,Zr) with L12 crystal structure. Microstructural analysis indicated a bimodal grain size distribution with fine equiaxed and columnar grains influenced by thermal gradients and secondary phase Al3(Sc,Zr). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests in 3.5wt% NaCl solution demonstrated that the alloy exhibits a less negative corrosion potential (Ecorr) and lower corrosion current density (icorr) compared to other Al-Mg-Sc-Zr alloys with higher Sc/Zr ratios, indicating superior corrosion resistance. The enhanced performance is attributed to the fine grain structure and the formation of a stable protective oxide layer facilitated by the higher Zr content.

It’s not waste, it’s a resource: Utilizing industrial waste fibers/mineral fillers to attain flame retardant biocomposites

Integrating natural fibers derived from local industrial waste streams into thermoplastic starch (TPS) proves to be a promising approach towards sustainable flame retardant biocomposites. Initially, three types of waste fibers from the agave, coconut, and leather industries were evaluated for their flame retardant properties in combination with aluminum trihydroxide (ATH), an environmental friendly flame retardant. Leather fiber (BLF) exhibited the best flame retardant performance and were further investigated along with ATH and varying amounts of bentonite nanoclay to enhance the residual protective layer. The combination of multiple components shows improvement in performance while reducing the total load of filler. The images of the fire residues revealed that a more enclosed surface correlates with a reduction in the peak of heat release rate. Whereas higher amounts of bentonite does not deliver further inprovements, only 1 phr nanoclay in the novel multicomponent system of TPS, ATH, BLF, and bentonite synergistically improved the UL-94 rating from HB to V1. The proposed system brings together the different approaches using a renewable biopolymer, natural waste fibres, and envirnmentally friendly flame retardancy and thus, is striking for its combination of outstanding sustainablity, instant feasability, and sufficient fire performance.

Investigation of 2-ethoxy-4-(oxiran-2-ylmethyl)phenol as a potentially effective anti-corrosion agent for C38 steel

This study presents a comprehensive investigation into the corrosion inhibition efficacy of the compound, 2-ethoxy-4-(oxiran-2-ylmethyl) phenol (EP), on C38 steel surfaces exposed to a highly corrosive 1 M HCl environment. Through a unique integration of experimental techniques—Electrochemical Impedance Spectroscopy (EIS), Potentiodynamic Polarization (PDP), Weight Loss (WL), Scanning Transmission Electron Microscopy coupled with X-ray Energy Dispersive Spectroscopy (STEM/XEDS)—and advanced theoretical methods, including Quantum Chemical Calculations (QCCs), Density Functional Theory (DFT), and Monte Carlo simulations (MCs), the study provides a deep and novel understanding of EP's corrosion inhibition mechanism. The findings reveal that EP acts as a mixed-type inhibitor, achieving a remarkable corrosion inhibition efficiency of approximately 92 % at 298 K by forming a protective layer on the steel surface. Notably, the adsorption of EP is characterized by both physisorption and chemisorption, adhering to the Langmuir isotherm model, a dual-mode mechanism that has been underexplored in similar compounds. The synergy between experimental data and theoretical simulations, particularly the use of DFT and MD simulations, elucidates the molecular interactions and adsorption behaviors that are critical to EP's effectiveness. This novel approach not only confirms EP's potential as a high-performance corrosion inhibitor but also contributes significant insights into the factors that govern corrosion inhibition, advancing the field's understanding of inhibitor design and application.

Sustainable Grease Lubrication Induced by Graphene Oxide and LiFePO4

This study investigates the possibility of modifying lubricating greases by 2D graphene oxide (GO) and lithium iron phosphate (LiFePO4) to enhance their tribological performance. GO's layered structure plays a crucial role in reducing friction by facilitating easy sliding between rubbing surfaces, making it an effective solid lubricant. The impact of these additives on friction reduction, wear resistance, and the tribolayer formation ability is evaluated by ball‐on‐disc tribometry with an emphasis on durability and sustainability. Comparative results reveal that unmodified greases exhibit a high susceptibility to wear, including oxide formation and severe plastic deformation. In contrast, greases with GO show a notable reduction in friction, while the addition of LiFePO4 contributes to the formation of a continuous protective layer that substantially reduces abrasive wear. The combination of GO and LiFePO4 results in a homogeneous, durable tribofilm that effectively protects surfaces against severe wear providing long‐term friction stability. Although lab‐scale LiFePO4 is used, the findings suggest a great potential for extending the useful life of recycled LiFePO4 from lithium‐ion batteries, similar to commercial LiFePO4 thus confirming significant improvements in the grease performance but also highlighting the potential to advance toward more sustainable solutions in industrial applications and electric vehicles.

Travel Medicine for Immunocompromised Travelers: An Essential Layer of Protection

Travel Medicine for Immunocompromised Travelers: An Essential Layer of Protection

Study on the Dynamic Evolution of Mining-Induced Stress and Displacement in the Floor Coal-Rock Induced by Protective Layer Mining

Protective layer mining is the most effective means to prevent and control coal and gas outbursts. In order to deeply understand the dynamic evolution law of mining stress and displacement of the bottom plate coal rock body in the process of protective layer mining, the effects of upper protective layer mining on stress variation and displacement deformation in the underlying coal seam were studied using the similar experiment and FLAC3D simulations. The results reveal that mining in the 82# coal seam notably alleviates pressure in the 9# coal seam below, with an average relief rate of 86.2%, demonstrated by the maximal strike expansion deformation rate of 11.3‰ in the 9# coal seam post-mining. Stress monitoring data indicates a stress concentration zone within 32 m ahead of the working face, and a pressure relief zone within 51 m behind it. The research provides a scientific foundation for pressure-relief gas extraction techniques, affirming the substantial impact of upper protective layer mining on alleviating pressure in underlying coal seams, enhancing safety, and optimizing mining efficiency.

What to do with your maintenance records for protection layers?

AbstractCollecting and analyzing operation and maintenance data is essential to process safety. The analysis aims to demonstrate that what is installed in the field achieves the required performance so that adjustments can be made if the required performance is not met. Very large organizations routinely have data collection systems and resources for data analysis. Midsized and smaller organizations collect the same data in various ways but often need help to analyze it. This paper presents examples of American Petroleum Institute (API) 754 Tier 3 and 4 metrics related to protection layers and how to use available plant data to support their analysis.

Influence of composition and temperature on oxide film formation for Fe-Cr-Ni alloys in simulated PWR primary water

ABSTRACT The growth of oxide films on Fe-Cr-Ni alloys in simulated pressurized water reactor (PWR) primary system environments was investigated, with focus on the influence of alloy composition and temperature. Oxide film thicknesses were measured for 90 specimens prepared from compact tension (CT) test pieces. Cross-sectional observations were also conducted on coupon specimens using scanning transmission electron microscopy (STEM). The behavior of Ni-based alloys, specifically Alloy 600, and Fe-based alloys, specifically Type 316 stainless steel, were compared. Ni-based alloys exhibit superior corrosion resistance due to slower Fe diffusion kinetics compared to Fe-based alloys, leading to the formation of a nickel-enriched protective layer at the metal-oxide interface. The oxidation rates of Ni-based alloys follow an Arrhenius-type temperature dependence. In contrast, Fe-based alloys show a more complex temperature-dependent behavior, with reduced oxidation rates at higher temperatures that are likely due to changes in oxide dissolution. Higher chromium concentrations in both alloy types improve the protectiveness of the oxide film towards corrosion by forming a more compact inner oxide layer. The study identifies three primary factors influencing oxide film growth: reactions at the metal-oxide interface, diffusion within the oxide layer, and processes at the oxide-solution interface. The relative significance of these processes varies depending on the alloy composition and temperature.

Functional organic 7,7,8,8‐tetracyanoquinodimethane artificial layers for the dendrite suppressed lithium metal anodes

AbstractThe large‐scale industrialization of lithium metal (Li), as a potential anode for a high energy density energy storage system, has been hindered by dendrite growth. The construction of an artificial solid electrolyte interphase layer featuring high ionic and low electronic conductivity has been verified to be a high‐performance strategy to confine the dendrite growth and promote the Li anode stability. Therefore, a functional organic protective layer is homogeneously deposited on the Li anode surface via an in situ chemical reaction between tetracyanoquinodimethane (TCNQ) and Li. The as‐synthesized Lin‐TCNQ organic film could efficiently trap non‐uniform Li deposition and restrain dendrite propagation. Particularly, an asymmetric M‐TCNQ‐Li|Cu cell with the Lin‐TCNQ layer breezed through a high Coulombic efficiency of 91.15% after 100 cycles at 1.0 mA cm−2. The M‐TCNQ‐Li|NCM622 cell delivered a high capacity of 143.40 mAh g−1 at 0.2 C and maintained a good cyclic stability of 110.44 mAh g−1 after 160 cycles. The analysis results of spectroscopic tests further demonstrate that the Lin‐TCNQ with the enhanced absorption energy is conducive to lithiophilicity and decreases the overpotential of Li deposition.

Dual Strategies of Na+ Electrolyte Additives and Dendrites Protective Ti3C2TX‐MXene/Zn Anode with 2D MXene Nanosheet Encased Niobium Pyrophosphate (NbP2O7) Composite Binder‐Free Cathode for Stable Zinc‐Ion Storage

AbstractZinc‐ion capacitors (ZICs) are promising next‐generation energy storage systems (ESS) owing to high safety, material abundance, environmental friendliness, and low cost; however, the energy density of ZICs must be improved to compete with lithium‐ion batteries (LIBs). Here, the study implements three strategies to enhance the electrochemical performance and manage dendritic growth on Zn anodes, including crafting a highly efficient redox electroactive niobium pyrophosphate (NbP2O7)/Ti3C2TX‐MXene binder‐free cathode, incorporating a NaClO4 additive electrolyte, and applying a protective Ti3C2TX‐MXene layer on Zn anode. The cathode facilitates rapid Zn2+ ion diffusion and a stable host structure. An electrostatic protection layer formed in additive electrolyte and MXene layers regulates the uniform distribution of the electric fields and supports the equalization of nucleation sites. These results are supported by density functional theory (DFT) calculations. The ZICs display an excellent specific capacitance (113.3 F g−1 at 1.5 A g−1) in aqueous additive electrolytes. The flexible solid‐state ZICs exhibits a volumetric capacitance of 865.05 mF cm−3, and an energy density of 0.347 mWh cm−3 at 2.29 mW cm−3 along with capacitance retention of >100% over 38 000 charge‐discharge cycles.

Gene Therapy for Inflammatory Cascade in Intrauterine Injury with Engineered Extracellular Vesicles Hybrid Snail Mucus-enhanced Adhesive Hydrogels.

Early hyper-inflammation caused by intrauterine injury triggered subsequent intrauterine adhesion (IUA). STAT1-mediated M1 macrophages are confirmed to secrete pro-inflammatory cytokines to accelerate inflammatory cascade and IUA formation by multi-omics analysis and experimental verification. However, clinically used hyaluronic acid (HA) hydrogels are prone to slip out of injury sites due to poor bio-adhesion properties. Therefore, there are still challenges in applying hydrogels for M1 macrophage intervention in IUA treatment. Herein, an engineered extracellular vesicles (EVs) hybrid snail mucus (SM)-enhanced adhesive hydrogels to improve bio-adhesion property is fabricated and M1 macrophage intervention through targeting delivery and STAT1 silencing is achieved. First, inspired by the high bio-adhesion capacity of SM, SM and gelatin methacrylate (GelMA) solution are mixed to construct GelMA/SM (GS) hydrogel. Then, folic acid-modified extracellular vesicles (FA-EVs) are synthesized for targeting the delivery of STAT1-siRNA. Upon injection of FA-EVs hybrid GS hydrogel into the uterine cavity, a protective hydrogel layer forms on the surface of injury sites and sustains the release of STAT1-siRNA-loaded FA-EVs to curtail M1 macrophages generation through inhibiting STAT1 phosphorylation, resulting in reduction of myofibroblasts activation and collagen deposition. In addition, the pregnancy rate and the number of fetuses in rats treated with this hydrogel were much higher than those in other groups, suggesting that the hydrogel could promote functional endometrial regeneration and restore fertility. Overall, this study presents a promising strategy for employing FA-EVs hybrid adhesive hydrogel with superior bio-adhesion properties and M1 macrophage targeting delivery for IUA treatment and uterus recovery.

Human-Centered Cybersecurity Revisited: From Enemies to Partners

Focusing on "enabling approaches" that treat humans as partners can add another layer of protection to our cybersecurity defenses.