Surface Protection Research Articles

Anti-friction and Wear Resistance Performance of Palm Olein Grease with Molybdenum Disulfide Additive

In this study, palm olein-based grease with a micro-molybdenum disulfide (MoS2) additive has been developed. The grease was prepared using various MoS2 concentrations to investigate the role of additives in improving grease performance. A four-ball tribological test was conducted to investigate the surface morphology, wear depth, and volume loss of the steel ball. The results indicated that the MoS2 additive reduced the coefficient of friction and wear scar diameter compared to pure palm olein grease. The value of 0.5 wt.% was considered the optimum value, reflecting the best grease performance indicated by low friction coefficient, wear diameter, wear depth, and volume loss. Elemental analysis revealed that the MoS2 additive was deposited onto the wear tracks, improving the surface protection. Thus, this additive was found to have a good potential for improving palm olein-based grease.

Three-Dimensional Turbulent Simulation of Bivariate Normal Distribution Protection Device

In response to the deficiencies in existing bridge pier scour protection technologies, this paper introduces a novel protective device, namely a normal distribution-shaped surface (BND) protection devices formed by rotating a concave normal curve. A three-dimensional turbulent SST k−ω model is constructed, and physical model experiments of conical surfaces are conducted to validate the mathematical model. The simulation analyzes longitudinal water flow, downflow, vorticity intensity, and shear stress within normal and conical surfaces. The results show that the downflow distribution in front of the pier spans a relative water depth of (−0.45, 0.67), with a peak velocity approximately 70% of the longitudinal flow velocity. Circulation forms within the surfaces, with the main vortex flux inside the BND being 33% lower than that inside the conical surface. The maximum shear stress coefficient inside the BND can reach 9, and the protective surface isolates the bed from the flow to prevent scouring by high shear stress. The velocity gradient at the edge of the surface is small, and the edge shear stress of the 3D normal distribution-shaped surface (BND) protection device is only one-third of that of the conical surface, preventing edge scouring. The large shear stress and its distribution area decrease monotonically with the increase in surface width. When the surface width is four times the diameter, the distribution range of the shear stress coefficient greater than 1 is very small. The study of three-Dimensional turbulence within the BND provides a numerical basis for an anti-scour design.

Surface modification of Ti40Cu40Zr11Fe3Sn3Ag3 amorphous alloy for enhanced biocompatibility in implant applications

This study focuses on the design of a new Ti based multicomponent amorphous alloy for the development of biocompatible implant materials with enhanced hemocompatibility and cytocompatibility. While this class of amorphous alloys has shown its potential for biomedical implant applications, there are major concerns due to the presence of elements such as copper which can lead to cytotoxicity in the human body during long term implantation. Nevertheless, copper is indispensable in the development of an amorphous alloy. Thus, the objective of this work is to selectively remove copper from the surface of the Ti40Cu40Zr11Fe3Sn3Ag3 (at%) amorphous alloy using the dealloying technique and produce a patterned protective passivated surface rich in Ti and Zr oxides. Nitric acid (HNO3) has been found to be effective in depleting copper from the sample surface. Optimization of treatment parameters such as temperature (70 °C and room temperature) yielded drastic differences in the morphology of the samples studied using Field-Emission Scanning Electron Microscopy. The treated sample surface demonstrated good hemocompatibility and cytocompatibility with primary human osteoblast cells (HOb) and human osteosarcoma cell line (Saos-2). Additionally, the treated samples showed higher ability to produce reactive oxygen species with respect to pristine samples, which could be convenient for preserving the implant from bacterial contamination. These findings contribute to the advancement of producing copper-depleted nanostructured Ti based amorphous alloys for biomedical implant applications.

Effect of substrate’s surface roughness on corrosion and wear rate of Ni-GO nanocomposite coating

Corrosion is a natural process that occurs when refined metal is converted into a more stable form, such as oxide, hydroxide, or sulfide. Wear is the failure of a surface due to dynamic contact between two surfaces. In offshore operations and environments, corrosion and wear are major problems due to the presence of corrosive and abrasive elements. The coating is a common surface protection method that enhances corrosion resistance and prolongs lifespan. In this work, a Ni-Graphene nanocomposite coating was fabricated using the electrodeposition method. This work aimed to fabricate a Ni-GO nanocomposite coating on mild steel with different surface roughness, to characterize the physical, mechanical, and chemical properties of the coating, and to investigate its corrosion and wear rate. The fabrication process involved preparing substrates coated with Ni-GO nanocomposite through a 45-minute constant current electrodeposition process. The coated specimens were characterized using X-Ray Diffraction Machine (XRD), Scanning Electron Microscope (SEM), Alicona Infinite Focus, Vicker’s Hardness Test, Raman spectroscopy, and Adhesion test. The corrosion and wear rate of the coatings were investigated using a Slurry Erosion tester and Salt Water spray, respectively. The results showed that the Ni-Go nanocomposite coating on a smooth surface roughness substrate achieved the highest microhardness, wear resistance, and corrosion resistance, with values of 468.8 HV, 0.182% weight loss, and 0.03% weight gain, respectively. This indicates that the specimen coated with a smooth surface roughness substrate provided better coating performance than the rough and medium surface roughness substrates.

Pre- and post-failure behaviour of a dike after rapid drawdown of river level based on material point method

The rapid drawdown of river level is very detrimental to the stability of dikes. In this paper, the entire slope failure process of a real dike with sandy soil interlayer after rapid river drawdown is accurately reproduced using the material point method (MPM). The analysis of pre-failure behaviour, in combination with field test results, reveals the triggering mechanism of such dike slope failure, demonstrating that the presence of sandy soil interlayer is the leading cause of dike instability. By tracking the response of the dike slope from failure initiation to runout termination, the failure mode of the dike slope with sandy soil interlayer is identified as a progressive and retrogressive failure mode, with shallow and deep-seated slip surfaces appearing successively. Parametric studies indicate the friction angle, cohesion, dilatancy, and permeability of the sandy soil play significant roles in dike slope stability. A relationship between the permeability of sandy soil and the maximum sliding displacement is also found. In the face of rapid river drawdown, river-facing slope surface protection is the most effective protection measure for such dike slopes with sandy soil interlayer, while traditional riprap protection at the slope toe has a limited protecting effect.

Cellulose Nanofiber as Mask/Personal Protective Equipment Surface Agent for Enhanced Anti-Bacterial Performance

The utilization of face-covering masks as an extended form of personal protective equipment has led to exponential waste measures during the COVID-19 pandemic, with estimations of up to 7200 tons of medical-type waste daily. A primary cause of this waste is surgical layered disposable masks that are constructed by melt-blown nonwovens usually made of non-biodegradable thermoplastic polymers like polypropylene. To increase widespread sustainable options to the public, commercialized or do-it-yourself-based fabric masks serve as a solution, but their resistance to harmful molecules is less than that of the medical-grade masks due to the fabric structure that leaves space for penetration. This project examines a water-soluble dispersion composed of cellulose nanofiber and polyvinyl alcohol, as a spray agent capable of treating the mask fabric surface to promote protection and sustainability against harmful aerosol particles. Cellulose nanofiber spray is also low-cost and biocompatible and could allow multi-use through home laundering. Polyvinyl alcohol was chosen as the water-soluble bonding system and polymer matrix to effectively adhere cellulose nanofiber onto the mask surface. This project follows the biomimic concept of dragonfly wings having uneven nanopillar surfaces to trap and rip bacterial membranes, as the spray decreases the water droplet contact angle on fabric surface, resulting in an increase in adhesion for incident bacteria and/or viruses.

Diving deep into the superior lubrication efficiency: A dynamic approach incorporating covalent organic polymer as strengthening booster in paraffin oil through a holistic blend of experimental and computational approaches

This research addresses the paramount importance of enhancing surface protection and minimizing friction in mechanical systems through the novel design of covalent organic polymer additive (COPA). COPA-1 and COPA-2 were intricately designed to enhance surface protection and minimize wear. Tribological analysis revealed that the addition of an optimized concentration of COPA-1 (25 ppm) to base oil significantly reduced friction (∼60.49% decrease) and wear (∼79.23% decrease) while increasing load-bearing capacity to 588 N. Rheological analysis confirmed excellent shear stability and desirable viscosity behavior. Furthermore, computational tools like density functional theory and molecular dynamics simulations provided valuable insights into the adsorption mechanisms and tribological performance. This integration of experimental and computational insights highlights the transformative potential of COPA in revolutionizing lubrication technology.

Impact of annealing temperature on the structural, morphological and optical properties of Ni doped ZnO nanostructured thin films synthesized by sol–gel methodology

Abstract Nickel doped zinc oxide (NZO) nanostructured thin films were prepared by hydrolysis and poly condensation reaction based on the sol–gel methodology. Nanostructured thin films were prepared over the glass substrate by dip coating. Prepared samples were annealed at 350 °C and 450 °C respectively to tune the desired characteristics. The XRD studies endorses the prepared films were polycrystalline in nature and high intensity sharp peaks were exhibited in (101) direction. EDAX results confirms the presence of Ni, Zn and O elements. FESEM results exhibits the spherical like morphology throughout the sample. The typical grain size of prepared samples are vary from 35 nm to 105 nm. Results of the FTIR divulges the different composition of prepared NZO samples. UV–vis spectrophotometer results reveals that the fabricated 1 at.% NZO thin films annealed at 450 °C were guaranteed to have the lowest absorbance of less than 10 %, while the 0.5 at.% NZO thin films have an energy band gap of roughly 3.08 eV. The obtained results of the prepared films are useful for devices like solar cells, optoelectronic devices, flat panel displays, anticorrosion and surface protection applicant against stainless steel etc.

CoCrFeMnNi0.8V/Cr3C2-Ni20Cr High-Entropy Alloy Composite Thermal Spray Coating: Comparison with Monolithic CoCrFeMnNi0.8V and Cr3C2-Ni20Cr Coatings

High-entropy alloys (HEAs) are revolutionizing the field of surface engineering, challenging traditional alloy frameworks with their superior mechanical attributes and resistance to corrosion. This investigation delves into the properties of the CoCrFeMnNi0.8V HEAs, both as a standalone material and when blended with Cr3C2-Ni20Cr, to evaluate their efficacy as cutting-edge surface treatments. The addition of vanadium to the CoCrFeMnNi0.8V alloy results in a distinctive microstructure that improves hardness and resistance to abrasion. The incorporation of Cr3C2-Ni20Cr particles enhances the alloy’s toughness and longevity. Employing high-velocity oxy-fuel (HVOF) thermal spray methods, these coatings are deposited onto steel substrates and undergo detailed evaluations of their microstructural characteristics, abrasion, and corrosion resistance. Findings reveal the CoCrFeMnNi0.8V coating’s exceptional ability to withstand corrosion, especially in environments rich in chlorides. The hybrid coating benefits from the combination of the HEA’s inherent corrosion resistance and the enhanced wear and corrosion resistance provided by Cr3C2-Ni20Cr, delivering comprehensive performance for high-stress applications. Through the fine-tuning of the application process, the Cr3C2-Ni20Cr reinforced high-entropy alloy coating emerges as a significant advancement in protective surface technology, particularly for use in marine and corrosive settings. This study not only highlights the adaptability of HEAs in surface engineering but also prompts further investigation into innovative material pairings.

Experimental Investigation on the Effects of Mineral Water Composition on the Leaching of Cement-Based Materials.

The common phenomenon observed for concrete in aggressive water is leaching, which involves the dissolution of cement hydration products. Many studies have focused on leaching in demineralised water or acid attacks, but mineral water still deserves further investigation. In most standards, the aggressiveness of a given water body is determined by its pH and not its composition. The effect of the calcium content of the water on degradation is yet to be determined. In this paper, the leaching of Portland cement-based mortar was induced by two types of drinking water with different calcium contents and buffer capacity in controlled conditions. The Langelier saturation index (LSI) was used to describe water aggressiveness based on the calco-carbonic equilibrium. The studied waters had the same pH but LSIs of +0.5 and -1.0 corresponding to scaling with respect to aggressive water; demineralised water was used as a reference. Microstructural damage was checked by TGA and X-ray microtomography. Macroscopic measurements were used to monitor global degradation. The soft water caused a 53% deeper deterioration of the mortar sample than the hard water. Soft water-induced leaching was found to be similar yet slower to leaching via demineralised water (with a mass loss of -2.01% and -2.16% after 200 days, respectively). In contrast, hard water induced strongly time-dependent leaching, and the damage was located close to the surface. The roughness of leached specimens was 18% higher in hard water than in soft water. The formation of calcite on the sample surface not only affects the leaching rate by creating a protective surface layer, but it could also act as a calcium ion pump.

The influence of heterogeneous catalytic processes on the heat flux to the surface and the chemical composition of the shock layer at high-speed flow around blunt bodies

Numerical modeling of the high-speed flow of a multicomponent dissociated gas around a blunt body was carried out for the flow regime corresponding to the thermally stressed point of the gliding trajectory of entry into the Earth's atmosphere in the surface temperature range of 800–2000 K. As boundary conditions, a stage-by-stage model of heterogeneous catalysis of the interaction of dissociated air with the thermal protection material SiO2 was used, previously developed by the authors on the basis of transition state theory and quantum mechanical calculations. The dependence of the modes of heterogeneous chemical reactions on the surface temperature and the density of surface adsorption centers and their influence on the chemical composition of the shock layer and the convective heat flux to the streamlined surface are analyzed. The contributions of individual mechanisms of heterogeneous recombination to the total rate of formation of molecules on the surface are estimated. The possibility of using the density of adsorption sites as an effective parameter when setting boundary conditions on a real thermal protection surface in flow problems is shown.

Investigation of the change in the characteristic properties of epoxy and silane coated natural stone surfaces

Travertine is a natural stone with macro and micropores; these pores are connected by capillary means. Their visual appearance and porous structure add a different style and diversify their usage areas. However, the large pore structure of travertine brings some limitations in determining the usage areas. In the study, protective solutions called silane and epoxy, which provide protection against water, were used to prevent and/or minimize decomposition in areas of use, depending on the porosity of the travertine, and their effects on travertine were compared. Treatment of both chemicals separately on the travertine surface was carried out by spraying, applying with a brush, and dipping into chemicals. With the findings obtained from the physical examinations after curing, the work continued using the applying and dipping method. The dipping method was evaluated with the chemical's 10, 20, and 40-minute waiting times. The study found that the best application conditions were chemical immersion for 10 minutes. However, in SO2 wear experiments, it was understood that surfaces treated with epoxy were more durable due to the high viscosity of the chemical. As a result, it has been determined that silane application provides more effective surface protection results than epoxy.

Influence of AR injection on shielding layer properties and surface protection from transient high heat loads under the QSPA plasma exposures

The paper presents experimental studies of a shielding plasma layer formation in front of a tungsten surface exposed with hydrogen plasma in the QSPA-M test-bed facility under the conditions of additional seeding of argon (Ar) along the target surface into the zone of plasma-surface interaction. A pulsed gas injector on the base of a fast electromagnetic valve has been developed for the local injection of Ar. The injector is capable of generating a homogeneous argon gas flow with a maximum concentration above n Ar = 6 × 1023 m−3 and a pulse duration of 0.5 ms. It is shown that the increase in the argon gas density in front of the surface leads to an essential decrease (in 1.5–2 times) in the energy load delivered to the target surface. In the presence of a strong magnetic field (up to 1 T), both the thickness of the shielding layer and the fraction of energy dissipated by the shield increase further. Even for moderate energy densities of the QSPA plasma streams in the experiments with Ar gas injection, less than 40% of the impacting plasma load is absorbed by the tungsten surface. The results demonstrate that this additional shielding attributed to the formation of a dense Ar plasma layer in front of the exposed W surface would be favourable for the divertor armour performance, causing the decreasing erosion of plasma-facing components in the course of transient events in a fusion reactor.

Ultra-High-Efficiency Corrosion Protection of Metallic Surface Based on Thin and Dense Hexagonal Boron Nitride Coating Films.

Quest for ultrathin and highly effective anticorrosion coating films is critical for both fundamental community of materials science and industrial economics. A two-dimensional hexagonal boron nitride (h-BN) film is a newly developed effective anticorrosion material due to its superior impermeability, thermal stability, and chemical stability. However, research in growth and anticorrosion properties of large-area dense h-BN coating films still lies in its infancy. Here, we report on the synthesis of a large-area and continuous dense few-layer (∼4) h-BN coating film onto a metal surface by chemical vapor deposition (CVD) and its anticorrosion properties both in air and seawater environments. Cu coated in h-BN, which functions as an anticorrosive coating, exhibits an impressively reduced corrosion rate (CR) in a 3.5% NaCl solution (which mimics a seawater environment) when compared to bare Cu (approximately 27 times). At 200 °C, the h-BN coating can prevent Cu foil's surface from oxidizing, although doing so will cause a significant amount of oxide particles to simultaneously form on the bare Cu surface. In the meantime, the performance of the h-BN film remains unaltered after 100 days in an atmospheric environment, demonstrating the ultrahigh stability and corrosion resistance of the as-grown h-BN film.

Performance and Surface Modification of Cast Iron Corrosion Products by a Green Rust Converter (Mimosa tenuiflora Extract)

One of the alternative materials used for conducting conservation treatment of iron artifacts is the rust converter, since it generates barrier properties and more stable oxides. The protective properties and surface modifications from using Mimosa tenuiflora extract as a green rust converter on a gray iron oxide layer were studied. The surface characterization was carried out using a Scanning Electron Microscope coupled to an energy-dispersive X-ray spectrometer (SEM-EDS), along with infrared spectroscopy (IR), Raman spectroscopy, X-ray Diffraction (XRD), and Water Contact Angle (WCA). Electrochemical characterization was performed with an Electrochemical Impedance Spectroscope (EIS) using 3.5 wt.% NaCl as the electrolyte. According to the results of the Raman spectroscopy and XRD, the layer of corrosion products formed after 90 days in the atmosphere was composed of goethite, lepidocrocite, maghemite, hematite, and magnetite. The surface of the corrosion products was transformed with the rust converter into an amorphous and microcracked layer. By IR, the Fe-O and C-O-Fe bonds associated with the iron chelate were found with absorption bands at 1540 and 1567 cm−1, respectively. By XRD, a modification of the magnetite crystallinity was observed. Finally, the Water Contact Angle and the protective capacity of the corrosion products were improved by the presence of the rust converter.

Flexible, hydrophobic, and robust composite films with sandwich structure for electromagnetic interference shielding and Joule heating

Electromagnetic interference (EMI) shielding materials with favorable flexibility, robustness, and multipurpose capabilities are urgently desired for smart wearable devices. Herein, flexible PDMS/cellulose nanofiber/Ag nanowire composite films with sandwich structures were successfully fabricated by a facile method. First, silver nanowires (AgNWs) were uniformly stacked in the upper part of the cellulose gel using a controlled two-step vacuum-assisted filtration; next, AgNWs were tightly embedded in the cellulose matrix by a hot-pressing strategy; finally, a hydrophobic protective layer, PDMS, was introduced. The water contact angle (WCA) of composite films could reach 121°. Compared with uniformly mixed films, AgNWs deposited only on the surface of the matrix allowed the conductivity to reach 381 S/cm at a low weight fraction of AgNWs (6 wt%). Thanks to such excellent conductivity, the composite films exhibited superior EMI shielding effectiveness (49 dB) at only 40 μm thickness, and Joule heating performance, i.e., the surface temperature reached 111.3 °C at 1.5 V driving voltage. It was worth noting that after bending and peeling damage, the WCA and EMI shielding effectiveness of composite films were not significantly impacted due to the hot-pressing strategy and hydrophobic surface protection. The robust composite films show huge application potential in the wearable electronics field.

Understanding the mechanism of organic corrosion inhibitors through density functional theory

Abstract Organic corrosion inhibitors have been widely used to prevent and mitigate the damaging effects of corrosion on metal surfaces. However, their underlying mechanisms of action and effectiveness are still not fully understood. In recent years, the use of density functional theory (DFT) has emerged as a powerful tool to investigate the interaction between organic inhibitors and metal surfaces at the molecular level. This review article provides an overview of the principles of DFT, its advantages and limitations, and its application to the study of organic corrosion inhibitors. The factors affecting the performance of organic inhibitors, such as molecular structure, functional groups, and metal surface properties, are discussed in detail. The interaction between organic inhibitors and metal surfaces, including the adsorption and desorption of inhibitors, the role of intermolecular forces, and the effects of pH and temperature, are also explored. Finally, the challenges and future directions in the development of organic inhibitors using DFT are highlighted, including limitations and challenges in using DFT and potential avenues for further research. Overall, this review demonstrates the potential of DFT to provide valuable insights into the mechanism of organic corrosion inhibitors and to guide the development of new and more effective inhibitors for the protection of metal surfaces.

Research on Surface Protection Technology of Aluminum Alloy Heat Sinks in Lithium Battery with Composite Anodic Oxide Film

Aluminum alloy sheets are immersed in a mixed acid electrolyte for anodic oxidation to prepare different types of anodic oxide films. The mass concentration of TiO2 nanoparticles in the electrolyte is appropriately increased, and under the action of liquid flow disturbance, the number of nanoparticles adsorbed on the surface of aluminum alloy specimens increases, which plays a good role in homogenizing current and filling, promoting more uniform film formation and inhibiting local excessive corrosion and dissolution of the anodic oxide film, Gradually generate a composite anodized film with good density. The composite anodized film constructs a protective barrier on the surface of the aluminum alloy heat sink in lithium batteries, which can effectively block corrosive media and has a better protective effect on the heat sink than conventional anodized film and mixed acid anodized film, thereby significantly improving the corrosion resistance of the heat sink.

Texture Inspection using the Voice Based Biometric Authentication in the Quantum Computation

Texture inspection has remained an important substance throughout the whole history because with the advances of the mobile graphics and many hardware, high-quality image processing for the basic wood texture in the Wolfram mathematical. We also used wood in the building material and household furniture to find out the type of wood that can be used as a specific material and to help in the development of the different wood texture in the android studio. Cedar is a fibrous and a porous structural tissue found in the roots of trees and other woody plants. The colour of the wood has been depend on the reflection of the most important component of the wood grain may be the process of refining or protection of the wooden surface in the production of the manufacturing cost 5 and 30%. Various Woods textures having the appearance of the wood that require the wood joints for the great variation between sapwood and heartwood.

Nanocosmeceuticals: Trends and Recent Advancements in Self Care.

The term cosmetics refers to any substances or products intended for external application on the skin with the aim of protection and better appearance of the skin surface. The skin delivery system promotes the controlled and targeted delivery of active ingredients. The development of this system has been driven by challenges encountered with conventional cosmeceuticals, including low skin retention of active components, limited percutaneous penetration, poor water dispersion of insoluble active ingredients, and instability of effective components. The aim is to create cosmeceuticals that can effectively overcome these issues. This review focuses on various nanocarriers used in cosmeceuticals currently and their applications in skin care, hair care, oral care, and more. The importance of nanotechnology in the sphere of research and development is growing. It provides solutions to various problems faced by conventional technologies, methods, and product formulations thus taking hold of the cosmetic industry as well. Nowadays, consumers are investing in cosmetics only for better appearance thus problems like wrinkles, ageing, hair loss, and dandruff requires to be answered proficiently. Nanocarriers not only enhance the efficacy of cosmeceutical products, providing better and longer-lasting effects, but they also contribute to the improved aesthetic appearance of the products. This dual benefit not only enhances the final quality and efficacy of the product but also increases consumer satisfaction. Additionally, nanocarriers offer protection against UV rays, further adding to the overall benefits of the cosmeceutical product. Figure 1represents various advantages of nanocarriers used in cosmeceuticals. Nanotechnology is also gaining importance due to their high penetration of actives in the deeper layers of skin. It can be said that nanotechnology is taking over all the drawbacks of the traditional products. Thus, nanocarriers discussed in this review are used in nanotechnology to deliver the active ingredient of the cosmeceutical product to the desired site.