NaCl Solution Research Articles

Features of the Application of Coatings Based on the ZrN System to Increase Resistance to Mechanical Wear and Corrosion of Titanium Alloy Products

The coatings of ZrN, (Zr,Ti)N, (Ti,Zr,Hf)N and (Ti,Zr,Nb)N deposited on the titanium alloy substrate were compared. The wear resistance in the pin-on-disk test together with the Al2O3 indenter and the corrosion resistance in 3.5% NaCl solution were studied. It was found that the (Zr,Nb,Ti)N coating has the best resistance to wear, but has low corrosion resistance. The (Ti,Zr,Hf)N coating, on the contrary, has the best corrosion resistance, but low resistance to wear. The ZrN coating has good corrosion resistance combined with good resistance to wear. This coating is best suited for use in friction conditions with a ceramic counterbody under the influence of seawater. An important resource for increasing the properties of coatings is increasing their adhesion to the substrate, which can be achieved in two combined ways: (1) complete removal of the original oxide layer from the surface of the substrate and (2) the use of optimal compositions of the adhesive sublayer, which have not only high adhesive properties in relation to both the substrate and the coating, but also high strength. While the introduction of Nb into the ZrN coating composition increases wear resistance and the introduction of Hf increases corrosion resistance, the ZrN coating without additives best resists wear and corrosion simultaneously.

Electroformation of Giant Unilamellar Vesicles from Damp Films in Conditions Involving High Cholesterol Contents, Charged Lipids, and Saline Solutions.

Giant unilamellar vesicles (GUVs) are frequently used as membrane models in studies of membrane properties. They are most often produced using the electroformation method. However, there are a number of parameters that can influence the success of the procedure. Some of the most common conditions that have been shown to have a negative effect on GUV electroformation are the presence of high cholesterol (Chol) concentrations, the use of mixtures containing charged lipids, and the solutions with an elevated ionic strength. High Chol concentrations are problematic for the traditional electroformation protocol as it involves the formation of a dry lipid film by complete evaporation of the organic solvent from the lipid mixture. During drying, anhydrous Chol crystals form. They are not involved in the formation of the lipid bilayer, resulting in a lower Chol concentration in the vesicle bilayer compared to the original lipid mixture. Motivated primarily by the issue of artifactual Chol demixing, we have modified the electroformation protocol by incorporating the techniques of rapid solvent exchange (RSE), ultrasonication, plasma cleaning, and spin-coating for reproducible production of GUVs from damp lipid films. Aside from decreasing Chol demixing, we have shown that the method can also be used to produce GUVs from lipid mixtures with charged lipids and in ionic solutions used as internal solutions. A high yield of GUVs was obtained for Chol/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) samples with mixing ratios ranging from 0 to 2.5. We also succeeded in preparing GUVs from mixtures containing up to 60 mol% of the charged lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS) and in NaCl solutions with low ionic strength (<25 mM).

Encapsulation of β-Galactosidase into Polyallylamine/Polystyrene Sulphonate Polyelectrolyte Microcapsules.

More than half of the global population is unable to consume dairy products due to lactose intolerance (hypolactasia). Current enzyme replacement therapy methods are insufficiently effective as a therapeutic approach to treating lactose intolerance. The encapsulation of β-galactosidase in polyelectrolyte microcapsules by using the layer-by-layer method could be a possible solution to this problem. In this study, adsorption and co-precipitation methods were employed for encapsulating β-galactosidase in polyelectrolyte microcapsules composed of (polyallylamine /polystyrene sulphonate)₃. As a result, the co-precipitation method was chosen for β-galactosidase encapsulation. The adsorption method permits to encapsulate six times less enzyme compared with the co-precipitation method; the β-galactosidase encapsulated via the co-precipitation method released no more than 20% of the initially encapsulated enzyme in pH 2 or 1 M NaCl solutions. In contrast, when using the sorption method, about 100% of the initially encapsulated enzyme was released from the microcapsules under the conditions described above. The co-precipitation method effectively prevents the complete loss of enzyme activity after 2 h of incubation in a solution with pH 2 while also alleviating the adverse effects of ionic strength. Consequently, the encapsulated form of β-galactosidase shows promise as a potential therapeutic agent for enzyme replacement therapy in the treatment of hypolactasia.

A grey relational analysis of the micro arc oxidation process parameters and their effects on Ti-6Al-7Nb coating performance and corrosion resistance for biomedical uses

Abstract In current investigation micro arc oxidation of Ti6Al7Nb alloy was done to improve its surface properties and corrosion resistance. Mixture of Na2SiO3, Na3PO412H2O and KOH is used as electrolyte. MAO treated Ti6Al7Nb specimens were examined using x-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) to examine their morphology and phase composition. It was observed that electrolyte composition is simultaneously included in the growing oxide layer during MAO process. From electrochemical study it was found that corrosion resistance of the Ti6Al7Nb increases during EIS testing in 0.9% NaCl solution. It was found that frequency, duty cycle, current and processing time effect the surface roughness, thickness, hardness and corrosion resistance of coating. Out of above mention parameters frequency and duty cycle has major impact on performance parameters. The objective of current investigation is to find out effects MAO process parameters on coating performance parameters such as coating thickness, hardness, surface roughness and corrosion resistance. At duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min, highest coating thickness 32.96 μm and surface roughness 3.3680 μm was obtained. Process parameters have the influence on pore size, biggest average pore size 3.8519 μm was obtained at duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min. Grey relational analysis is done to determine which process variable has the most influence on performance parameters. From grey relational analysis technique, it was observed that duty cycle 50%, frequency 500 Hz, current 300 mA, and processing time 7.5 min are ideal process parameters for higher coating thickness, hardness, surface roughness and better corrosion resistance. From grey relation analysis it was also found that frequency has most significant impact on performance parameters after that duty cycle, then current and at last processing time.

Experimental investigation on the moisture movement behavior of granites

This study comprehensively investigates the hygric performance of two commonly used types of granite in masonry, each characterized by distinct porosity levels. A series of experimental tests, including capillary absorption, one-dimensional drying, cup methods, vacuum saturation, sorption/desorption isotherms, mercury intrusion porosimetry, and ultrasonic pulse velocity, was conducted in different directions and by using both pure water and NaCl solutions. The results highlight pronounced anisotropy in the granite’s hygric response, with significant directional differences in liquid and vapor moisture movement, as well as ultrasonic wave propagation. Granite with lower porosity and a finer pore structure exhibited hysteresis effects and more pronounced hygroscopic behavior, while granite with higher porosity showed greater capillary activity. The presence of salt crystals within the pore network significantly influences vapor and liquid transport properties, porosity, and moisture storage capacity. The gradual formation of sodium chloride crystals on drying surfaces noticeably altered drying kinetics, influenced by salt concentration and pore characteristics. These findings provide valuable insights into the hygric properties of granite, essential for understanding its durability and informing moisture transfer numerical models.

Corrosion resistance analysis of Al2O3-TiO2 composite ceramic coatings on carbon steel pipe surfaces

This study investigates the corrosion resistance of Al2O3-TiO2 composite coatings reinforced with multi-walled carbon nanotubes (MWCNTs) on carbon steel pipe surfaces. Coatings were deposited using atmospheric plasma spraying (APS) and high velocity oxy-fuel (HVOF) techniques. Microstructural analysis revealed that HVOF-sprayed coatings exhibited denser and more homogeneous structures compared to APS-sprayed coatings. Electrochemical tests in 3.5 wt% NaCl solution showed that the HVOF-sprayed Al2O3-13 wt% TiO2-1.5 wt% MWCNT coating demonstrated the lowest corrosion current density of 7.6 × 10−9 A/cm2 and the most positive corrosion potential. Hot corrosion tests in a simulated boiler environment (500°C, 1000 h) revealed that this coating also exhibited minimal weight gain (0.9 mg/cm2) and thickness loss (2 μm). The corrosion rate of the optimal coating was 0.05 mm/year, significantly lower than the bare carbon steel (2.45 mm/year). XRD analysis of corroded samples showed that HVOF-sprayed coatings maintained their original phase composition without detectable substrate corrosion products. The superior corrosion resistance of the HVOF-sprayed Al2O3-13 wt% TiO2-1.5 wt% MWCNT coating is attributed to its optimized composition, dense microstructure, and the reinforcing effect of MWCNTs. These findings provide valuable insights for developing advanced coating solutions to mitigate corrosion-related challenges in the oil and gas industry and other harsh industrial environments.

Corrosion Resistance Comparison of High Manganese Steel in 0.01mol/L NaHSO3 Solution and 3.5wt.% NaCl Solution

Corrosion Resistance Comparison of High Manganese Steel in 0.01mol/L NaHSO3 Solution and 3.5wt.% NaCl Solution

Influence of the oxidizing technique on the biocompatible and corrosion properties of Ti6Al4V in a physiological environment

This work aims to evaluate the corrosion and biocompatibility properties of oxide films generated on Ti6Al4V alloys using both traditional and novel methods. Oxide films were generated by anodization and plasma treatment to achieve a blue surface finish. The oxide films were then characterized and compared to a native film formed on the Ti6Al4V.Electrochemical tests, incorporating potentiodynamic tests and electrochemical impedance spectroscopy, were employed to define the electrochemical resistance of oxides in an environment simulating biological exposure. In vitro tests were conducted to study ion release and biocompatible properties over a 6-week period of exposure to a 0.9 wt% NaCl solution, at body temperature. Various spectroscopic techniques, including ToF-SIMS, XRD, and Raman analysis, were used to study the structure and chemistry of the oxide films. The sub-surface layer was analysed by microstructural investigation.The type of oxidation was found to have a key influence on the oxide composition, especially with respect to the depth distribution of the individual alloy elements through the oxide film. The oxidation process determines which of the alloying elements are released into the environment, as a result of the corrosion reactions.

YOLOv8-licorice: a lightweight salt-resistance detection method for licorice based on seed germination state.

Seeds will display different germination states during the germination process, and their good or bad state directly influences the subsequent growth and yield of the crop. This study aimed to address the difficulties of obtaining the images of seed germination process in all time series and studying the dynamic evolution law of seed germination state under stress conditions. A licorice sprouting experiment was performed using a seed sprouting phenotype acquisition system to obtain images of the sprouting process of licorice in full-time sequence. A labeled dataset of licorice full-time sequence sprouting process images was constructed based on the four states of unsprouted, sprouted, cracked, and shelled in the sprouting process. An optimized model, YOLOv8-Licorice, was developed based on the YOLOv8-n model and its effectiveness was demonstrated by comparative and ablation tests. Different salt stress environments were simulated via NaCl aqueous solution concentration, and germination experiments of licorice seeds were performed under different salt stresses. The germination state of licorice under different salt stress environments was detected using the YOLOv8-Licorice detection model. Percentage curve of licorice seeds in an unsprouted state displayed a continuous decreasing trend. For the percentage curve of licorice seeds in the sprouted state, an increasing and then decreasing trend was observed under the condition of 0-200 mmol/L NaCl solution, and a continuous increasing trend was observed under the condition of 240-300 mmol/L NaCl solution. Licorice seeds in the cracked state demonstrated percentage curves with an increasing and then decreasing trend under the condition of 0-140 mmol/L NaCl solution and a continuous increasing trend under the condition of 160-300 mmol/L NaCl solution. The percentage curve of licorice seeds in shelled state displayed a continuous increasing trend in 0-200 mmol/L NaCl solution condition and remained horizontal in 220-300 mmol/L NaCl solution condition. Overall, this study provides a valuable method involving the seed sprouting phenotype acquisition system and the proposed method for detecting the germination state of licorice seeds. This method serves as a valuable reference to comprehensively understand the seed sprouting process under triggering treatment.

Ginger powder as sustainable and eco-friendly corrosion inhibitor for the protection of steel reinforcement bars

In the present studies, ginger powder has been used as an eco-friendly admixture for the cement mortar. Different amounts i.e. 0 wt% (M1), 0.10 wt% (M2), 0.25 wt% (M3) and 0.50 wt% (M4) ginger powder was mixed in the cement mortar (M1) and assessed the durability. The ginger powder with 0.50 wt% (M4) improves the compressive strength by 17 % owing to the water reducing capability, which enhance the hydration reaction and fill the pore matrix of the cement mortar. The active ingredient of ginger powder i.e. shogaol adsorbs on the steel rebar surface through leaching mechanism by interaction of oxygen (O) and п-electrons with iron (Fe) and provide corrosion protection at longer duration of continuous immersion in 3.5 wt% NaCl solution. Following 173 d in a 3.5 wt% NaCl solution, the M4 sample exhibits 82.10 % corrosion inhibition efficiency. Therefore, it is suggested that ginger powder could be a potential eco-friendly admixture to be used in construction industries to get high durability performance in the coastal areas.

Sonophotopythochemical Functionalization of Graphene Oxide - Al - Zn Bimetal Nanocomposite for Corrosion Inhibition

The corrosion performance of steel in the marine environment has been a primary concern of engineers and garnered significant interest due to its industrial significance. To address this concern, the incorporation of green corrosion inhibitors as coating materials in mild steel has been extensively studied recently. This paper explores the synthesis of graphene doped with bimetal aluminum-zinc (GO-Al-Zn) nanocomposites via sonophoto-phytochemical functionalization using Chayote (Sechium edule) leaf extract as the doping agent to produce a corrosion inhibitor. The synthesized nanocomposites were characterized using FTIR, SEM-EDS, XRD, and TEM. The optimal nanocomposite, with a 55% Al - 45% Zn ratio, demonstrated successful bio-reduction, good dispersion, reduced particle size, and a rhombohedral crystal structure. When incorporated into an epoxy coating and applied to mild steel, the GO - 55% Al - 45% Zn coating achieved a high corrosion inhibition efficiency of 98.06% (gravimetric method) and 98.45% (electrochemical method) in 3.5 wt% NaCl solution. This study highlights the promising potential of GO - 55% Al - 45% Zn nanocomposite as an eco-friendly corrosion inhibitor. Future research should explore optimizing the functionalization process and exploring long-term environmental stability.

Influence of Low-Energy High-Current Electron Beam Exposure on the Phase Composition and Corrosion Resistance of the AM60 Magnesium Alloy

The surface of an AM60 (Al – 5.5, Zn – 0.2, Cu – 0.009, Fe – 0.005, Si – 0.1; Ni – 0.002, Mn – 0.3 wt.%, Mg – the rest) magnesium alloy was exposed to a low-energy high-current electron beam. After the irradiation, the content of the β-phase (Mg17Al12) decreases and the aluminum content increases in the alloy surface layer. After the exposure to the electron beam, the corrosion resistance of the alloy in a 1-molar NaCl solution increases significantly compared to the initial state. The physical reason for the increase in the alloy corrosion resistance after exposure to the electron beam is the higher corrosion resistance of the oxide film formed on the alloy surface due to the increased aluminum content.

Drimia maritima as a New Green Inhibitor for Al-Si Alloy, SAE Steel and Pure Al Samples in 0.5 M NaCl Solution: Polarization and Electrochemical Impedance Analyses

The corrosion inhibition effects of Drimia maritima (L.) Stearn sin. Urginea maritima (L.) Backer on three different materials, i.e., as-cast Al-7 wt.% Si alloy, SAE 1020 low carbon steel, and commercially pure Al samples, into a stagnant and naturally aerated 0.5 M NaCl solution are evaluated. For this purpose, both the potentiodynamic polarization curves and electrochemical impedance spectroscopy with an equivalent circuit are utilized. It is found that inhibition effect increases up to certain minor Drimia maritima content. Adsorption isotherms (e.g., Langmuir and Temkin) indicate that all three examined materials comprise physical adsorption mechanisms. Al-Si alloys attained inhibition efficiencies of about 96% at 25 °C with 1250 ppm of Drimia maritima and ~43% with 625 ppm at 45 °C. On the other hand, the cp. Al and SAE 1020 samples attain ~89% and 68% with 1250 ppm and 500 ppm at 25 °C, respectively. This clearly indicates that the dosage of Drimia maritima green inhibitor into NaCl solution possesses certain susceptibility for each distinctive material examined. Impedance parameters obtained by using CNLS (complex non-linear least squares simulations) are correlated and discussed.

COMPARATIVE STUDY ON CORROSION BEHAVIOR OF 316 STAINLESS STEEL AND Ti6Al4V ALLOY IN SIMULATED SEAWATER

This work presents a systematic investigation of the corrosion behavior of two materials, 316 stainless steel (316), and Ti6Al4V alloy (Ti6Al4V), in simulated seawater (3.5[Formula: see text]wt.% NaCl solution). This includes electrochemical tests, immersion experiments, scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) analyses. The polarization curves demonstrate that passivation occurs in both alloys. The lower self-corrosion and passivation current densities of Ti6Al4V indicate that its corrosion resistance is superior to that of 316. However, the impedance spectrum of the 316 shows a larger capacitive arc radius, which is indicative of the presence of a more robust passivation film on its surface. The results of the immersion experiments demonstrate that 316 exhibits a high-corrosion rate under static conditions, which can be attributed to the instability of the passivation film and environmental factors. However, under dynamic conditions, the corrosion rate is lower due to the effect of scouring. In contrast, Ti6Al4V demonstrated superior corrosion resistance in a variety of environmental conditions. In the context of simulated seawater, both 316 and Ti6Al4V exhibited varying degrees of corrosion behavior. Consequently, when selecting corrosion-resistant materials, it is imperative to select suitable materials according to the specific use environment and requirements.

Adipose-derived mesenchymal stem cells mitigate doxorubicin-induced cardiomyopathy in rats

Purpose: To investigate the effect of adipose-derived mesenchymal stem cells (ADMSCs) on doxorubicin (DOX)-induced cardiomyopathy in rats. Methods: A total of 30 male Sprague-Dawley rats were randomized into control (n = 10) and study groups (n = 20). Control group received no intervention while the study group received DOX administered intraperitoneally (i.p.) six times daily at a dose of 2.5 mg/kg/ day. The study group was divided into 2 groups. One group received DOX + normal saline (0.9 %w/v) sodium chloride (NaCl) solution ntraperitoneally at a dose of 1 mL/kg/day. Another group received DOX + ADMSC at a dose of 2.0 x 106 cells/kg intraperitoneally twice a week. Biochemical parameters and histopathological changes in blood and heart tissue samples were compared among groups. Results: Caspase-3 immuno-expression, plasma malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), growth differentiation factor-15 (GDF-15), pro-brain natriuretic peptide (Pro-BNP), troponin, heart transforming growth factor–β (TGF-β) were significantly lower in DOX+ ADMSC compared to DOX + saline group (p &lt; 0.05). However, caspase-3 immune expression and the number of regularly arranged cardiomyocytes significantly decreased in DOX + ADMSC group compared to DOX + saline group (p &lt; 0.05). Conclusion: Adipose-derived mesenchymal stem cells (ADMSCs) reduce caspase-3 immunoexpression, restore cardiac histology, and ameliorate DOX- induced cardiac injury. Further investigation and clinical trials are recommended, especially to determine the continued safety and efficacy of AD-MSC-based therapy in cardiac injury.

Corrosion Evaluation and Mechanism Research of AISI 8630 Steel in Offshore Oil and Gas Environments.

In this study, we optimized the traditional composition of AISI 8630 steel and evaluated its corrosion resistance through a series of tests. We conducted corrosion tests in a 3.5% NaCl solution and performed a 720 h fixed-load tensile test in accordance with the NACE TM-0177-2016 standard to assess sulfide stress corrosion cracking (SSCC). To analyze the corrosion products and the structure of the corrosion film, we employed X-ray diffraction and transmission electron microscopy. The corrosion rate, characteristics of the corrosion products, structure of the corrosion film, and corrosion resistance mechanism of the material were investigated. The results indicate that the optimized AISI 8630 material demonstrates excellent corrosion resistance. After 720 h of exposure, the primary corrosion products were identified as chromium oxide, copper sulfide, iron oxide, and iron-nickel sulfide. The corrosion film exhibited a three-layer structure: the innermost layer with a thickness of 200-300 nm contained higher concentrations of alloying elements and formed a dense, cohesive rust layer that hindered the diffusion of oxygen and chloride ions, thus enhancing corrosion resistance. The middle layer was thicker and less rich in alloying elements, while the outer layer, approximately 300-400 nm thick, was relatively loose.

The Influence of HCO3− Concentration on the Corrosion Resistance of 6061 Aluminum Alloy in NaCl Solution

The Influence of HCO3− Concentration on the Corrosion Resistance of 6061 Aluminum Alloy in NaCl Solution

Sustainable quaternary binders made from metallurgical wastes of northeast Mexico: strength, hydration products, and durability.

In this research, four industrial wastes were used for up to 80% as supplementary cementitious materials (SCMs) in cement mortar systems: ground granulated blast furnace slag, electric arc furnace slag, basic oxygen furnace slag, and waste limestone powder. Quaternary cementitious blends were prepared and studied for up to 120days. Workability, compressive strength, durability, microstructures, and sustainability studies were performed and compared with Portland cement references. Results showed that more than 30MPa in compressive strength can be achieved by > 50% replacement with SCMs; only 9% below the reference. Neither H2SO4 nor MgSO4 attacks resulted in critical damages; nevertheless, curing under NaCl solution showed detrimental behavior. C-S-H with a low Ca/Si ratio was identified in the mortars as the main hydration product, possibly intermixed with stratlingite, C-A-S-H and/or hydrotalcite. Environmental impact for the blended cements was determined as the CO2eq. factor from a simple life cycle assessment. The embodied greenhouse gasses varied in 260.2-541.4kg CO2eq./ton of binder depending on the formulation. This was 40-70% less than Portland cement (922.6kg CO2eq./ton). The production of the raw materials dominated the polluting emissions, while freight, grinding, and sieving had little environmental impact.

Enhancing the Wear Performance of 316L Stainless Steel with Nb2O5 Coatings Deposited via DC Sputtering at Room Temperature under Varied Environmental Conditions

Niobium-based oxides have garnered increased attention in recent years for their remarkable enhancement of corrosion resistance, as well as biofunctional properties of various metallic materials, including 316L SS. However, the mechanical properties of these promising coatings have not been fully elucidated. This study investigated how much the environmental conditions (air, artificial saliva, and NaCl solution) impact the wear performance of 316L SS without and with Nb2O5 coatings deposited via the reactive sputtering technique. The results exhibited a notable decrease in friction coefficient (55% in air, 18% in artificial saliva, 10% in 0.9 wt% NaCl solution), wear area (46% in air, 36% in AS, 17.5% in 0.9 wt% NaCl solution), and wear rate (44.0% in air, 19.5% in AS, 12.0% in 0.9 wt% NaCl solution). Ultimately, the results obtained in the present study elucidate the synergistic mechanisms of corrosion and wear in 316L SS containing Nb2O5 coatings, highlighting its significant potential for applications in the biomedical sector.

Synergistic Effect of Sn Doping in TiO2 Nanoparticles as an Additive in Anti‐Corrosion Coatings

ABSTRACTCorrosion is a major problem and protective coatings offer an effective solution. However, organic coatings are often associated with microcracks caused by the evaporation of solvents during coating preparation. This study investigates the use of titanium dioxide (TiO2) nanoparticles as a coating additive to protect mild steel surfaces. Additionally, doping TiO2 with tin (Sn) is believed to enhance its properties due to the reduced size of the nanoparticles. These nanoparticles were synthesised using the sol–gel method and subjected to various analyses. The coated mild steel samples were prepared using the dip‐coating method and immersed in 3.5 wt.% sodium chloride (NaCl) solution for 30 days. Electrochemical impedance spectroscopy (EIS) and Tafel polarisation showed that the Sn‐doped TiO2 nanoparticles as an additive improved the corrosion resistance, as evidenced by a positive shift in corrosion potential (Ecorr) and reduced corrosion current density (Icorr).