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Copper pillar bumps are widely utilized in advanced packaging technologies, representing a crucial foundation for 3D packaging. However, the mechanical properties of Sn3Ag bumps on copper columns often fall short of meeting increasingly demanding service conditions. Additionally, the loss of effectiveness due to excessive growth of intermetallic compounds at the interface needs to be addressed. To enhance the Sn₃Ag bumps and inhibit the excessive growth of intermetallic compounds, CoSn₃ nanocrystals were prepared, and Sn₃Ag–CoSn₃ composite copper pillar bumps were fabricated through composite electroplating. Upon reflowing, the CoSn3 nanocrystals decomposed, resulting in a significant formation of (Cu,Co)6Sn5 nanoparticles within the Sn3Ag matrix. The (Cu,Co)6Sn5 nanoparticles not only strengthen the solder joints by pinning, but also significantly reduced the excessive growth of interfacial intermetallic compounds, ultimately improving the service performance and reliability of the solder joints.

To improve the corrosion resistance and wide the application of Al alloy sheet in the engineering production, a corrosion potential gradient along the thickness of the Al alloy sheet was fabricated using the sprayed Zn layer. The process of arc spraying was employed to obtain the Zn coating with optimizing the parameters. Electrochemical testing was conducted on the surface of Al alloy sprayed with Zn layers at different depths. As the depth in the thickness direction increases, the content of Zn alloy elements gradually decreases and the potential gradually increases. This exhibits a gradual decrease in corrosion tendency. The results of electrochemical impedance spectra (EIS) revealed the existence of pitting corrosion on the surface of the Al alloy. This even extended to the underlying substrate material. In contrast, the Zn coating, when exposed to a corrosive environment, demonstrated the beneficial cathodic effect as a sacrificial anode and the protective function of a passivating film, thus mitigating corrosion. The gradual increase in charge transfer resistance in the impedance spectrum suggested that the corrosion resistance of the sample is increasingly improved. Therefore, it exhibited remarkable resistance to corrosion. Additionally, the SEM surface morphology and XRD pattern were utilized to further explain the corrosion mechanism of the arc-sprayed Zn coating. The Zn coating can provide sacrificial protection to the Al layer due to its higher negative potential and localized corrosion reactivity. This is attributed to the micro-galvanic couples formed between the Zn and Al layer, thus increasing the corrosion resistance of the sheets.

Ni–Al based coating is one of the common high temperature and corrosion resistant protective coatings. In the present paper, the effect of Si content on the formation of Al2O3 layer and the corrosion resistance of Ni–Al coating to chloride molten salt was studied. The research results show that the Ni–Al coatings with varying Si content mainly form NiAl2O4 and Al2O3 oxide layers after pre-oxidation, and form a three-layer structure after molten salt corrosion. The appropriate amount of Si added to the Ni–Al coating can promote the formation of the α-Al2O3 layer during pre-oxidation and thermal corrosion, improving the corrosion resistance of the coating to high temperature chloride molten salt, and hindering the diffusion of Cr elements. Particularly, the Ni–Al coating with Si content of 1.2 at.% has the thickest and densest Al2O3 protective layer, showing the best corrosion resistance. The simulation results shows that compared with the Ni–Al coating without Si, the Cl atoms in the Si-added Ni–Al coating need to overcome greater energy barriers to diffusion during the molten salt corrosion process, which also indicates that the addition of Si can improve the corrosion resistance of the coating.

Microwave absorption (MA) materials are essential for protecting against harmful electromagnetic radiation. In this study, highly efficient and ultrawide-band microwave-absorbing fabrics with superhydrophobic surface features were developed using a facile dip-coating method involving in situ graphene oxide (GO) reduction, deposition of TiO2 nanoparticles, and subsequent coating of a mixture of polydimethylsiloxane (PDMS) and octadecylamine (ODA) on polyester fabrics. Owing to the presence of hierarchically structured surfaces and low-surface-energy materials, the resultant reduced GO (rGO)/TiO2-ODA/PDMS-coated fabrics demonstrate superhydrophobicity with a water contact angle of 159° and sliding angle of 5°. Under the synergistic effects of conduction loss, interface polarization loss, and surface roughness topography, the optimized fabrics show excellent microwave absorbing performances with a minimum reflection loss (RLmin) of −47.4 dB and a maximum effective absorption bandwidth (EABmax) of 7.7 GHz at a small rGO loading of 6.9 wt%. In addition, the rGO/TiO2-ODA/PDMS coating was robust, and the coated fabrics could withstand repeated washing, soiling, long-term ultraviolet irradiation, and chemical attacks without losing their superhydrophobicity and MA properties. Moreover, the coating imparts self-healing properties to the fabrics. This study provides a promising and effective route for the development of robust and flexible materials with microwave-absorbing properties.

Local defects in coatings allow aggressive electrolytes penetrate to the coating/substrate interface, accelerating the corrosion of the exposed Mg substrate and compromising its biocompatibility. In this work, self-healing calcium hydrogen phosphate dihydrate (DCPD) coating incorporated with 3,5-dinitrosalicylic acid (3,5-D) or 5-amino salicylic acid (5-A) is designed on Mg. The results reveal that the self-healing and corrosion resistance performance of DCPD improves after adding 3,5-D/5-A. Namely, incorporating 3,5-D/5-A into DCPD accelerates the self-healing process and repair the coating at the initial stage. The released 3,5-D/5-A additives could adsorb on the exposed Mg surface and combine with the Ca2+ ions to precipitate. The interfacial adsorption mechanism of 3,5-D/5-A additives is disclosed by quantum chemical calculation. The simultaneously responsive adsorption and deposition of additives during coating degradation increase the thickness and compactness of the deposition layer at the coating defects, further inhibiting corrosion and stabilizing pH. These findings suggest taking biocompatibility recovery into consideration of preparing self-healing coating for biomedical applications.

In the last decades, corrosion control of metals and their alloys has been of environmental, aesthetic, economic, and technical importance. Ecologically acceptable, environment-friendly, and readily available corrosion inhibitors are one of the best options for protecting metals against corrosion. In this regard, use of polymers for inhibiting metallic corrosion is an authentic and acceptable practice, with a low environmental threat. Polymers may be used as composites, blends, or isolation for optimal inhibitory effects. Inhibition efficiencies of corrosion inhibitors were determined using mass loss, electrochemical impedance spectroscopy, potentiodynamic polarization techniques, etc. The present study gives the idea about natural, synthetic, and conducting polymers and their utilization for corrosion inhibition applications. Effects of halide ions as additives or surfactants on their anticorrosion performances are also discussed. Polymeric materials as coatings are reviewed to align with recent research interests, such as cost-effectiveness, environment friendliness, and self-healing products, which are more convenient to synthesize and use in future applications.

Complex formation structures lead to significant differences in the failure mechanisms of hobs. WC-reinforced medium entropy composite coatings exhibit excellent comprehensive properties. However, the wear mechanism of coatings in different formation structures is still unclear. In this study, FeNiCr-WCx (x = 0, 40, 50, 60 wt%) composite coatings were prepared on the surface of H13 steel using laser cladding technology. The friction and wear mechanism of FeNiCr-WC composite coatings under different friction pair conditions was discussed. The results show that FeNiCr-WC composite coatings mainly consist of reinforced phase, lamellar eutectic structure and solid solution phase. As the WC content increases, the content of M6C and carbide phases in these coatings increases. The average microhardness of 40WC, 50WC and 60WC coatings is 3.28 times, 3.61 times and 4.20 times that of H13 steel, respectively. The wear rates of 40WC, 50WC and 60WC coatings are respectively about 0.25, 0.10 and 0.06 times that of FeNiCr coating under Al2O3 friction pair conditions. Three-body wear and oxidation wear mainly occurred on the surface of FeNiCr-WC composite coatings. The wear rates of 40WC, 50WC and 60WC coatings are respectively about 0.34, 0.35 and 0.16 times that of FeNiCr coating under Si3N4 friction pair conditions. Glaze layers with high Si content were formed on the surface of 50WC and 60WC coatings. The glaze layer is prone to cracking and peeling, resulting in increased wear rates for both coatings. As the hardness of the coating increases, the GCr15 friction pair undergoes severe abrasive wear.

The agriculture sector is currently facing a decline in plant productivity and yield. Different technologies are being developed to combat these risks. However, innovation in existing technologies is required. Nanotechnology has the potential to solve these difficulties by modifying traditional farming practices and approaches. Nanoparticles (NPs) can bind and transport various substances, such as plant nutrients, and govern their slow release over a longer period, which can reduce the danger of nutrient losses while maintaining environmental safety. In this aspect, the role of zinc oxide nanoparticles (ZnO NPs) and their derivatives in agriculture has recently sparked a lot of interest. ZnO NPs can be coated with different compounds which enhance their biocompatibility within the plant cells. The unique nanostructures and nano-characteristics of ZnO NPs and their derivatives have resulted in the development of a novel approach for boosting plant development and productivity as well as improved stress tolerance via targeted delivery and slow-release mechanism, resulting in enhanced nutrient use efficiency, regulating phytohormone levels, enhancing root morphology, and increasing enzyme activity, leading to their application as nanofertilizers. There are important knowledge gaps regarding the long-term environmental consequences and the specific biochemical pathways influenced by ZnO NPs. This review aims to provide an overview of the most recent advancements in the use of ZnO NPs in agriculture, identify areas where more research is needed, and suggest potential future research directions.

Metallic bipolar plates (BPPs) manufactured by stamping have great commercialization prospects in proton exchange membrane fuel cells (PEMFCs) owing to their significant advantages of low density, small volume, high mechanical strength, and low cost. The development of coatings on metallic BPPs is essential for its application in PEMFCs. However, both the design and preparation of metallic BPP coatings face great challenges of increasing requirements, low efficiency, insufficient performance, and high cost. In present work, the design, manufacture and evaluation of coatings on metallic BPPs are extensively reviewed and explored. The changing requirements including corrosion resistance, conductivity, hydrophobicity, and mechanical properties for metallic BPP coatings and corresponding evaluation methods are comprehensively discussed. Especially, improved mechanical properties are critical for the emerging precoated metallic BBPs. Numerous coatings previously developed are quantitatively compared to provide guidance for the coating material selection. For highly efficient development of high-performance and low-cost coating, the material-structure-properties relationship of coatings is thoroughly summarized as the coating design principle. Moreover, different design methods including experimental, calculation, and machine learning are respectively in depth explored and compared, suggesting that machine learning combining decreased experiments and material calculation is a high-efficiency and effective method for coating design.

Long-lasting protective coatings are essential, particularly under harsh operating conditions. Surface coatings provide a flexible alternative; electrodeposition is becoming an established approach for protecting steel. The intent of this study is to determine how effectively zinc oxide (ZnO) coatings for mild steel corrosion protection effect when integrated with snail shell particle (SSP). The experimental setup consisted of producing a coating bath with ZnO and SSP particles, then electrodeposting the mixture under conditions onto polished steel surfaces. The created coatings were subjected to an array of tests, including electrical conductivity and resistivity testing, morphological analysis using SEM/EDS, corrosion testing in a 1M HCl solution, hardness testing. The findings show that when SSP content increases, steel corrosion rates significantly decrease, suggesting improved corrosion resistance from 21.85(mm/yr) to 12.80(mm/yr), and polarization resistance of 4.47E+01(Ω) to 8.00E+01(Ω). Morphological examination shows that SSP particles are dispersed throughout the coating matrix, which promotes adhesion and stability. Also, coatings with more SSP show better electrical characteristics. Overall, the study shows how ZnO-SSP coatings can shield mild steel components from adverse conditions and have prospective uses in sectors where surfaces resistant to corrosion are needed.

Sutures are essential for wound healing. Sutures cannot influence biological healing processes; hence their efficacy is still limited. Active healing sutures must be made. We created a biocompatible, biodegradable polymer suture material to reduce allergic reactions. Non-biocompatible materials that cause tissue rejection and inflammation impede wound healing. To improve wound healing, cellulose and chitosan (CS) were utilized to make a suture material. Dip coating with graphene oxide (GO) nanoparticles improved the suture material. The properties were assessed using FTIR, SEM, EDS, and other analytical methods. In an immersion investigation, coated suture material deterioration in simulated bodily fluid (SBF) was examined. When coated suture material inhibited bacterial growth, its antibacterial activity was tested. These properties suggest that GO nanoparticles, cellulose, and chitosan may be coupled for the first time to generate an aggressive mediator. Coated suture biocompatibility is assessed using in vitro cell survival and hemolysis tests. This paper reviews the latest suture material innovations and explores how natural polymers can advance this area.

Natural fiber-reinforced composites are becoming popular day by day because of their low cost and renewable nature. However, a major concern of these composites is water absorption. To minimize the water absorption in natural fiber-reinforced composites, wood varnish coating was used in this paper to investigate the effect of this coating on water absorption and mechanical properties of jute fiber-reinforced composites. Four types of composites were fabricated using the hand lay-up technique, among them on Type 1 no coating was used, Type 2 was surface coated, Type 3 was fiber coated and Type 4 was both fiber and composite surface coated. Water absorption, tensile, bending, short beam shear, and impact tests were performed on the composite specimens according to their respective ASTM standards to see the effect of coating. Both fiber and fracture surface morphology were observed using Scanning Electron Microscope. It was found that the water absorption was significantly reduced for Type 2 (50.31 %) and Type 4 (56.01 %) specimens. However, the tensile strength and bending strength were reduced by 74.17 %, and 72.71 % for Type 3 and 77.07 % and 84.24 % for Type 4 composites while for Type 2, they were slightly increased (7.26 % and 1.13 %). The ILSS of Type 3 and Type 4 were reduced by 69.34 % and 58.07 % respectively while it was reduced by only 4.49 % for Type 2 composite. On the other hand, the impact energy absorption was increased by 85.32 % for Type 4 composite. The findings of this study suggest that Type 2 composite (only composite surface coating) has the overall best performance and wood varnish coating has the potential to reduce the water absorption on natural fiber-reinforced composites.

The present study used polymers such as PLA and ABS filaments for the 3D printing parts with varying layer thicknesses. The mechanical properties and surface finish of the as-printed and epoxy resin-coated samples were investigated. Noteworthy findings indicate that when the PLA material is printed at a layer thickness of 0.06 mm followed by no coating one can achieve superior tensile strength of approximately 39 MPa as compared to 20 MPa of ABS material. The ultimate tensile strength of the coated materials averaged approximately 15 MPa for both PLA and ABS. The surface roughness of PLA material printed with a 0.06 mm layer thickness showed a 95.13 % reduction after coating. Despite ABS samples being harder than PLA material, the layer thickness emerged as the most influential factor in enhancing the hardness. The dominance of lower layer thickness over other conditions is particularly evident in the modulus of elasticity. In addition to the experimental investigation, a non-linear structural analysis of the uniaxial tensile behaviour of the coated and uncoated 3D prints was also carried out. The fracture modes and deformation behaviours in numerical modelling and experimental results across various parametric conditions were found to be in good agreement. Specifically, the numerical results at lower loading conditions for a layer thickness of 0.06 mm PLA and ABS samples, in the uncoated conditions, mirrored the experimental outcomes.

In this study, composite adsorbents are developed by using various compositions of activated carbon (AC)/polyvinyl alcohol (PVA) with graphite powder (GP). The optimal adsorption material chosen for the adsorption cooling system (ACS) is found to be composite A, which comprises 93 % AC, 5 % graphite powder, and 2 % PVA. This selection is made based on the physical characterization of the composite materials by BET, FESEM, adsorption capacity, desorption capacity and thermal conductivity tests. The specific cooling power (SCP), coefficient of performance (COP), and exergetic COP of the adsorption chiller are experimentally evaluated. By maintaining the optimal desorption and condenser temperatures (Tdes = 70 °C and Tcon = 35 °C), the maximum COP, SCP and exergetic COP of the system are found to be 0.582, 206 W/kg and 0.19 for packed bed and 0.738, 261.37 W/kg and 0.25 for coated bed, when the adsorption temperature (Tads) = 30 °C and evaporation temperature (Teva) = 25 °C. The Freundlich isotherms exhibit a better correlation with the vapour pressure of methanol. The samples exhibited no deformations after 17 adsorption/desorption cycles, confirming the durability of the activated carbon. The more uniform coating thickness and smooth surface structure could ensure long-term stability and performance of the adsorbent.

Silicones such Sylgard 184 are widely employed in biological applications due to their versatile properties. However, their inherently adhesive surfaces can restrict their application, especially in direct contact with damaged biological tissues, potentially compromising patient comfort. To enhance the surface properties of Sylgard 184 while maintaining its transparency in the visible spectrum, a novel low-temperature method (70 °C) has been developed. This method involves immersing PDMS in a solution of titanium (IV) ethoxide in THF, thus inducing swelling of the silicone's polymer network, followed by the diffusion and condensation of titanium (IV) ethoxide within the polymer matrix. The resulting hybrid material, incorporating amorphous titanium oxide within the silicone network, exhibits significantly increased surface hardness compared to unmodified Sylgard 184, while retaining transparency and improving biological behaviour. The elaborated method holds promising potential for enhancing the performance of silicone-based materials in diverse biomedical applications.

The High Entropy Alloy (HEA) coatings exhibit diverse properties contingent upon their composition and microstructure, addressing current industrial requirements. Machine Learning (ML) regression emerges as a proficient solution for predicting the properties of HEA coatings, offering a significant reduction in experimental work. The ML regressions including Support Vector Regression (SVR), Gaussian Process Regression (GPR), Ridge Regression (RR), and Polynomial Regression (PR), are effectively employed to predict Young's modulus of HEA coated Stainless Steel (SS) through a significant database. The statistical responses of the developed regression models are analyzed through evaluation indices of Coefficient of determination (R2), Mean Absolute Error (MAE), and Root Mean Square Error (RMSE). Among the regression models, the 2-degree PR model stands alone with a high prediction accuracy of R2-0.95, MAE-16.12, and RMSE-21.53. The 2-degree PR model demonstrates a significant correlation between the predicted and experimental Young's modulus, contributing to the accurate prediction of unknown Young's modulus of the HEA-coated SS. The prediction of Young's modulus by the PR model is more reliable, as proved by an error percentile of ±4.76 %, compared to the experimental values of Young's modulus.

The safety and reliability of high-speed trains depend on the brake disc. In order to improve the lifetime of brake disc and reduce the waste of resources, a coating with higher microhardness and well wear resistance is urgently needed. The effect of chromium content on the microstructure, microhardness and wear resistance of NiCr coating has been studied. Nano-crystalline Ni and NiCr coatings with superior mechanical properties were successfully prepared on the 30CrNiMo steel substrate by pulse current electrodeposition method. The inclusion of formic acid and sodium citrate was found to significantly expedite the co-deposition of Ni and Cr. The NiCr coatings with various Cr contents were prepared at current densities ranging from 200 to 300 mA/cm2. These coatings significantly enhance microhardness and wear resistance of the substrate. The microhardness of the NiCr coating increased to 603 HV, outperforming pure Ni coating by 119 HV. Additionally, the wear rate of the NiCr coating decreased by 50% at a load of 10 N in comparison to the Ni coating. The high microhardness is attributed to grain refinement and solution strengthening. This study successfully addresses the challenges associated with electrodepositing Ni-based coatings on 30CrNiMo steel substrate and lays a theoretical foundation for the utilization of Ni-based coatings to enhance the tribological properties of materials used in high-speed train brake disc.

To address the functional failure caused by low-surface-tension liquid wetting and adhesion in superhydrophobic materials, in this study, we constructed a bilayer coating with superamphiphobic properties using an epoxy (Ep) bonding layer and an organosilane-grafted attapulgite (OG-ATP) layer through spray-coating technique. The prepared superamphiphobic bilayer coating exhibited high contact angles (CAs) and low sliding angles (SAs) for cold water (25 °C), hot water (85 °C), glycerol, ethylene glycol, peanut oil, and even n-hexadecane (CA = 150.4 ± 0.3° and SA = 7 ± 2°) with surface tension of 27.5 mN m−1. Surface morphology and elemental analysis confirmed the coating's unique micro-nano hierarchical structure and low surface energy characteristics. Electrochemical impedance spectroscopy (EIS) results showed that the surface charge transfer resistance (Rct) and low-frequency modulus (|Z|0.01Hz) were enhanced by 6–7 orders of magnitude compared to the bare aluminum alloy substrate. The anti-corrosion performance remained stable even after 5 days of 3.5 wt% NaCl immersion. Additionally, icing experiments with water droplets at −10 °C and −15 °C revealed a significant delay in ice formation on the substrate protected by the bilayer coating. The development of this protective material, combining superamphiphobicity, self-cleaning, corrosion resistance, and anti-icing functions, will provide advanced technological reserves in areas such as marine, aviation, transportation, and manufacturing.

This study introduces an innovative approach to enhance the antibacterial properties of lithium disilicate glass ceramics, widely used in dental restorations. We explored the efficacy of tannic acid (TA) and polyethyleneimine (PEI) as coating agents, capitalizing on a robust defense against microbial colonization and biofilm formation. We employed various analytical techniques, including differential thermal analysis (DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), to characterize the physical, chemical, and antibacterial properties of the TA/PEI coated glass-ceramics. Results indicated a notable improvement in the mechanical properties, such as Weibull modulus, elastic modulus, and fracture toughness of the coated samples. Moreover, the TA/PEI coatings displayed superior thermal stability and effective leaching behavior in different pH, pertinent to dental applications. Significantly, the TA/PEI coatings exhibited high antibacterial activity against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria, making them promising candidates for enhancing the bioactivity of dental restorative materials. This study lays the foundation for developing advanced antibacterial coatings for dental applications, aiming to improve patient outcomes in dental care.

Much attention has been paid to the coating of energetic materials to improve their properties. However, the present coating technology has drawbacks, and it fails to meet the requirements of engineering applications. In this study, observation of the toad spawning process gave an idea for efficient preparation of millimeter-sized coated granules by directly using unrefined HMX. In this technique, the preparation device was cheaper and requirements were simpler. The mechanism of formation mechanism and curing of the coated granules were studied. The preparation process and its formula were continuously optimized during the exploration process. The morphologies and properties of the granules coated with different binders were studied by various techniques and the industrial productivity was evaluated. The coated granules showed regular and full morphology after optimization of the formula and were not easily deformed. Compared with unrefined HMX, the flowability was significantly improved, the mechanical sensitivity was reduced, the response time for ignition was shorter, and the flame intensity was higher. This method solved the problems of sedimentation of particulates and curing of large-sized droplets, while its high production efficiency and little wastage provided a new reference for producing large-sized high-energy coated granules for use in engineering applications.

Background: This in vivo study evaluated the effect of graphene oxide and graphite coatings, coupled with the micro-arc oxidation (MAO) surface roughening technique, known for their mechanical strength, chemical stability, and antibacterial properties. The main objective was to assess the degree of improvement in osseointegration of titanium implants resulting from these interventions. Materials and methods: In this study, 32 female rats were utilized and randomly allocated into four groups (n = 8 each): machined surface titanium implants (control), those roughened by the MAO method, those coated with graphene oxide-doped MAO, and those with a graphite-doped MAO coating. Titanium implants were surgically placed in the right tibia of the rats. Rats undergoing no additional procedures during the 4-week experimental period were sacrificed at the end. Then, the implants and surrounding bone tissues were separated and embedded in acrylic blocks for reverse torque analysis. Using a digital torque device, the rotational force was applied to all samples using a hex driver and racquet until implant separation from the bone occurred, with the corresponding values recorded on the digital display. Then, statistical analysis was performed to analyze the data. Results: No statistically significant difference between the groups was observed in the biomechanical bone–implant connection levels (N/cm) (P = 0.268). Post-hoc tests were not required because no discernible differences were identified between the groups. Conclusion: Within the scope of this study, implants treated with the MAO method, along with those coated with graphene oxide- and graphite-doped MAO method, did not exhibit significant superiority in terms of osseointegration compared to machined surface titanium implants.

In this study, a novel approach was employed to address the persistent challenge of biofouling in membrane-based separation processes. The method involved enhancing the antifouling and antibacterial properties of polyethersulfone (PES) membranes through the incorporation of dragon's blood resin (DBR) and silver nanoparticles (AgNPs). Four types of membranes with different compositions were prepared and subjected to various characterization including antibacterial test. The introduction of silver coating (M-DB/Fe/Ag) led to an increase in hydrophilicity of the membrane, which changed to higher permeability and very good humic acid rejection (R: 98.32 %) and flux recovery ratio (FRR: 95.87 %). SEM analysis revealed the presence of crystalline particles, indicating a successful Ag coating, followed by a stable negative charge on the membrane surface. Among the prepared membranes, only M-DB/Fe/Ag exhibited antibacterial activity against E. coli with an inhibition zone diameter of 9.46 mm. Based on its anti-biofouling properties, the results have significant potential for various applications.

Objective: Fracture-related infection (FRI) remains a major concern in orthopaedic trauma. Functionalizing implants with antibacterial coatings are a promising strategy in mitigating FRI. Numerous implant coatings have been reported but the preventive and therapeutic effects vary. This systematic review aimed to provide a comprehensive overview of current implant coating strategies to prevent and treat FRI in animal fracture and bone defect models. Methods: A literature search was performed in three databases: PubMed, Web of Science and Embase, with predetermined keywords and criteria up to 28 February 2023. Preclinical studies on implant coatings in animal fracture or defect models that assessed antibacterial and bone healing effects were included. Results: A total of 14 studies were included in this systematic review, seven of which used fracture models and seven used defect models. Passive coatings with bacteria adhesion resistance were investigated in two studies. Active coatings with bactericidal effects were investigated in 12 studies, four of which used metal ions including Ag+ and Cu2+; five studies used antibiotics including chlorhexidine, tigecycline, vancomycin, and gentamicin sulfate; and the other three studies used natural antibacterial materials including chitosan, antimicrobial peptides, and lysostaphin. Overall, these implant coatings exhibited promising efficacy in antibacterial effects and bone formation. Conclusion: Antibacterial coating strategies reduced bacterial infections in animal models and favored bone healing in vivo. Future studies of implant coatings should focus on optimal biocompatibility, antibacterial effects against multi-drug resistant bacteria and polymicrobial infections, and osseointegration and osteogenesis promotion especially in osteoporotic bone by constructing multi-functional coatings for FRI therapy. The translational potential of this paper: The clinical treatment of FRI is complex and challenging. This review summarizes novel orthopaedic implant coating strategies applied to FRI in preclinical studies, and offers a perspective on the future development of orthopaedic implant coatings, which can potentially contribute to alternative strategies in clinical practice.

The demand for advanced materials with exceptional mechanical and thermal properties has increased significantly in various aerospace, automotive, and power generation industries in recent years. Inconel 718 superalloy is preferred due to its exceptional strength, corrosion resistance, and elevated temperature stability. However, machining Inconel 718 poses substantial challenges due to its inherent toughness, low thermal conductivity, and high work hardening rate. This study investigated the drilling performance of Yttrium Stabilized Zirconia (YSZ)-coated Inconel 718 superalloy using Abrasive Water Jet machining. The objective of this study is to comprehensively examine the effects of process parameters, such as water pressure (WP), abrasive flow rate (AFR), and stand-off distance (SOD), on the quality and efficiency of drilling YSZ-coated Inconel 718. Experimental investigations are conducted using a specially designed AWJ setup. Further, the dragon-fly optimization algorithm is proposed to identify optimal drilling process parameters to simultaneously minimize output responses like entry, exit, and erosion diameters. Comparing the proposed algorithm's performance against that of the Harmony Search and Jaya algorithms demonstrates its effectiveness.

The icing of wind turbine blades leads to a decrease in output power, seriously jeopardizing the economic benefits and operational reliability of wind farms. Conventional deicing techniques require expensive equipment and consume a large amount of energy. Low-interfacial toughness coatings without energy dissipation are believed to be a highly potential passive deicing technology. However, the durability in service is facing challenges. Herein, low-interfacial toughness PDMS coatings were prepared by physical blending. Through the optimization of added plasticizers and SiO2, PDMS coatings with excellent large-scale deicing performance were obtained. The constant deicing force and ice adhesion strength were reduced to 14.69 N/cm and 12.63 kPa, respectively. Moreover, a systematic durability assessment of the PDMS coating was carried out to address the actual operating conditions of wind turbines. Fortunately, the results showed that the PDMS coating could withstand 200 icing/deicing cycles while maintaining constant deicing force and ice adhesion strength of less than 50 N/cm and 30 kPa, respectively. After long-term thermal aging (21 days), UV irradiation (42 days) and salt spray corrosion (20 days), the PDMS coating still retained superior icephobicity and outstanding large-scale deicing performance. This work contributes to the research and development of low-interfacial toughness materials for large-scale deicing applications on wind turbine blades.

Traditional hot-dip galvanized coatings, typically single-silver in color, present increasing aesthetic challenges in diverse applications, while prevailing organic coating methods involve complex processes with high energy consumption and pollution emissions. In this study, a novel hot-dip process for in-situ synthesis of color coating on steel was proposed, capable of producing various uniform color coating. The microstructure of color coatings on steel was systematically examined, and an assessment of their corrosion and weather resistance was conducted. The results demonstrate the sequence of typical color variation is gold, purple, blue, cyan, red, green, and grey. By controlling the immersion temperature range, and regulating the final stable color of the oxide film. The coloration mechanism mainly is attributed to the light interference on the Mn oxide film. The cyan and brown coatings mainly consist of the dense rod-like ζ-FeZn13 phases which provide a structural foundation for corrosion resistance. Furthermore, the brown coating exhibited excellent weather resistance.

Pomelo peel pectin coating preserves egg quality by sealing eggshell pores, making it a useful alternative when refrigeration is unavailable. This research aimed to assess the effectiveness of pomelo peel pectin coating in maintaining the quality and nutritional content of chicken eggs during 35 days of storage at room temperature. The eggs were analyzed across four treatments: uncoated eggs stored at room temperature (URT, control), uncoated eggs stored at 4 °C (U4 °C), pomelo peel pectin coated eggs stored at room temperature (PRT), and pomelo peel pectin coated eggs stored at 4 °C (P4 °C). Weight loss percentage, Haugh unit (HU), yolk index (YI), and albumen pH were measured weekly. Nutritional composition (protein, fat, ash, moisture, carbohydrate, and energy) was determined every two weeks. Results showed that PRT had lower weight loss and higher HU and YI compared to URT. No significant differences were observed between U4 °C and P4 °C. Both refrigerated treatments retained a Grade A HU on day 35, whereas PRT maintained a Grade A HU until day 28. Pomelo peel pectin coating had no significant impact on albumen pH and nutritional values. Overall, the coating effectively preserved egg quality by reducing weight loss and maintaining HU and YI at room temperatures (25–30 °C). However, it did not show the same effects at 4 °C. Without refrigeration, the coating offers an alternative method for extending shelf life, maintaining Grade A HU for up to 28 days at room temperature.

In the absence of refrigerated storage, coating materials may offer effective alternatives for preserving egg shelf life. Durian rind, rich in pectin, seals eggshell pores, while nisin, a natural antimicrobial peptide, helps reduce bacteria. This study investigated the effectiveness of durian rind pectin combined with nisin to preserve egg quality and reduce bacterial contamination. Eggs were divided by treatment: (1) uncoated or control; (2) durian rind pectin coated; and (3) coated with durian rind pectin and nisin. All eggs were kept at room temperature (25–30 °C) for five weeks and evaluated weekly for weight loss, Haugh unit (HU), yolk index (YI), egg white pH, and total bacterial count on eggshells and egg content. Results were that durian rind pectin coating, with or without nisin, significantly reduced weight loss (8.5–8.7 % in coated eggs versus 10.5 % in uncoated eggs by day 35); maintained Grade A HU until day 28 (uncoated eggs dropped to Grade B by day 14); and preserved a higher YI with a lower egg white pH compared to uncoated eggs. The total bacterial count on eggshells was lowest in eggs coated with durian rind pectin and nisin (4.06 log10 CFU/mL), compared to durian rind pectin alone (5.15 log10 CFU/mL) and uncoated eggs (5.85 log10 CFU/mL) at day 35. These findings suggest that durian rind pectin coating may extend egg shelf life up to 28 days by maintaining a Grade A HU and an egg white pH under 9.2. Adding nisin enhances antibacterial activity, reducing bacterial count on eggshells.

This study focuses on creating a superhydrophobic, durable, and exceptionally transparent coating with dual-scale roughness by naturally formed raspberry-like particles. This approach facilitates the management of surface roughness at both single and dual scales through variations in surface functionalization temperature. We illustrated that adjusting the temperature of organosilanes functionalization on the surface allows for various reactions, such as the direct grafting of metallic precursors or their polymerization on the surface, resulting in the formation of large raspberry-like particles.We investigated the impact of nanoparticle concentration, functionalization duration, and reaction temperature on surface properties. Our results reveal that a concentration of 1.5 % SiO2 nanoparticles, combined with surface functionalization using TCMS for 4 h at 3 °C, provides the optimal conditions for creating a surface that combines superhydrophobicity, transparency, and acceptable durability. The resulting surface exhibits an impressive contact angle of 158.9°, a sliding angle of 2°, and a transmittance rate of 82 %.Furthermore, the coating demonstrates remarkable resistance to abrasion for up to 35 cycles and can withstand temperatures up to 280 °C. It also offers enhanced protection against UV radiation for 50 h and improved resistance to sand abrasion for up to 30 s, enduring bombardment pressures of up to 6 bars. Moreover, the coating presents several advantages in terms of surface cleaning.

The effect of hot isostatic pressing (HIP) on the microstructure and properties of hot dip aluminum coating cooled in a magnetic field was investigated in this study. In order to improve the microstructure and properties of magnetic dip aluminum coating, hot isostatic pressing technology was used for post-treatment. Initially, a traditional aluminum-impregnated coating was prepared on the surface of titanium alloy TA15, an alternating electromagnetic field was applied during the forming and solidification process of the coating. Finally, the coating was treated with hot isostatic pressing technology. Analyzed three different coatings of the microstructure and element distribution, and tested the microhardness of the coatings at various positions. The test results revealed that the TA15 titanium alloy hot-dip aluminum coatings obtained through the three different processes exhibited a gradient structure. Compared with the traditional hot-dipped aluminum air-cooled coating, when an appropriate intensity of alternating electromagnetic field was applied during the coating solidification process, the outer coating structure was enhanced, the number of holes was reduced, the microstructure density increased, and the number of cracks significantly decreased. The defects of the 800 °C hot isostatic magnetic cold and hot dip aluminum coating were repaired under high temperature and pressure, resulting in a uniform and fine microstructure. The comprehensive properties of the magnetic cold and hot dip aluminum coating on the surface of the titanium alloy were effectively enhanced through hot isostatic pressing.

M420 stainless steel has good mechanical properties, but its corrosion resistance is poor, which limits its application in marine conditions. Single-technology processing has been unable to meet the development needs of modern industry. In this work, plasma nitrocarburizing (PNC) and CrN/CrTiAlSiN/WCrTiAlN multi-layer coating were carried out on M420 martensitic stainless steel by hollow cathode-assisted plasma treatment and multi-arc ion plating, respectively. The modified layers were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The results show that the nitrocarburized layer effectively improves the hardness gradient between the coating and the substrate. The presence of the composite strengthening layer enables the sample to obtain a thick and dense corrosion-resistant surface, effectively blocking the invasion of the corrosive medium. The corrosion rate of the PNC + C sample decreased by an order of magnitude. Combining hollow cathode-assisted rapid nitrocarburizing technology and multi-arc ion plating technology can significantly improve the mechanical properties and corrosion resistance of M420 stainless steel in a shorter time. The duplex surface-treated M420 stainless steel by plasma nitrocarburizing and WCrAlTiSiN multilayer coating exhibited excellent corrosion resistance compared to the nitrided and coated M420 stainless steel.

The complex biological process of osseointegration and the bio-inertness of bone implants are the major reasons for the high failure rate of long-term implants, and have also promoted the rapid development of multifunctional implant coatings in recent years. Herein, through the special design of peptides, we use layer-by-layer assembly technology to simultaneously display two peptides with different biological functions on the implant surface to address this issue. A variety of surface characterization techniques (ellipsometry, atomic force microscopy, photoelectron spectroscopy, dissipation-quartz crystal microbalance) were used to study in detail the preparation process of the dual peptide functional coating and the physical and chemical properties, such as the composition, mechanical modulus, stability, and roughness of the coating. Compared with single peptide functional coatings, dual-peptide functionalized coatings had much better performances on antioxidant, cellular adhesion in early stage, proliferation and osteogenic differentiation in long term, as well as in vivo osteogenesis and osseointegration capabilities. These findings will promote the development of multifunctional designs in bone implant coatings, as a coping strategy for the complexity of biological process during osteointegration.

In this study, the corrosion behavior and degradation mechanism of Ti–Pt-coated stainless steel bipolar plates were investigated through electrochemical tests and surface analysis in a polymer electrolyte membrane water electrolysis (PEMWE) operating environment. The coated bipolar plate has a corrosion current density of only 1.68 × 10−8 A/cm2, which is an order of magnitude lower than that of the bare SS316L substrate (1.94 × 10−7 A/cm2), indicating that its corrosion resistance is superior to that of bare SS316L substrate. However, in the PEMWE operating environment, the protection efficiency of the coating and the corrosion resistance of the coated bipolar plate decreased. The degradation of the coated bipolar plate can be attributed to electrolyte penetration into the blistering areas of the coating layer with micro voids. Defects in the coating layer occur because of the pressure of oxygen gas generated within the coating layer under high-potential conditions, thereby exposing the substrate to the electrolyte and corrosion.

For wearable smart textile sensors, stability, accuracy and multi-functionality are key objectives. Achieving the optimal application requires delicately balancing the crucial physical properties of strain sensors, presenting a key technological challenge. This study addresses these challenges by presenting several properties and potential applications of a triple hierarchic polymeric knitted fabric. The fabric incorporates an internal conductive network constructed with silver nanowires (AgNWs) and polydopamine (PDA) coating on its outer surface. This innovative textile successfully strikes a balance between strain sensing and electromagnetic interference shielding while concurrently exhibiting biocompatibility and antimicrobial properties. Significantly, acknowledging the susceptibility of measurements from polymer-based strain sensor materials to time drift, we introduce both a modeling approach and a novel calibration technique. This advancement facilitates the generation of stable cyclic sensing signals, even under substantial deformations of up to 80 % at a high stretching speed. Importantly, it provides a practical solution for addressing signal drift observed in flexible sensors when utilized in environments characterized by long-term and large deformations.

This paper presents the surface plasmon resonance (SPR) characteristics of D-shaped silica multimode optical fiber coated with bilayer silver-gold film. The effect of various coating thicknesses on the SPR characteristics was investigated through simulation using COMSOL Multiphysics. The inner layer Ag thickness varied from 20 nm to 60 nm, and the outer layer Au thickness ranged from 5 nm to 25 nm. Prior simulation results indicated that a single-layer silver (Ag) coating produces a narrower plasmonic curve than a single-layer gold (Au) coating. The confinement loss and the resonance wavelengths were simulated for the sensing medium with a refractive index (RI) range of 1.40–1.45. The simulation results show that the Ag/Au bilayers coated sensors have better full-width-half-maximum (FWHM) and figure-of-merit (FOM) than the single-layer coated sensors. The Ag/Au with a 40 nm/5 nm thickness exhibits the highest confinement loss, with a wavelength sensitivity of 10 000 nm/RIU and a figure-of-merit (FOM) of 500 RIU−1. The proposed sensor using a D-shaped optical fiber coated with Ag/Au layers has a high potential for remote sensing applications involving chemical liquids, offering robust and accurate measurements within the tested refractive index range.

In order to reveal the correlation between the accelerated corrosion test of epoxy polysiloxane coating and the real sea environmental test, the real sea environmental test was carried out in the atmosphere and tidal range area of Zhairuoshan Island in the East China Sea, and the multi-factor coupling test I (Cycle of 7-day xenon lamp aging test + 7-day Wetting-drying test) and test II (Cycle of 7-day xenon lamp aging test + 3-day damp heat test + 4-day salt spray test) were designed with reference to the environment of the East China Sea. The correlation between indoor accelerated corrosion test and real sea environmental test was analyzed by using Grey Relation Analysis, Spearman's rank correlation coefficient and Acceleration factor conversion method. The results show that both the indoor accelerated corrosion test and the real sea environmental test have corrosive effects on the epoxy polysiloxane coating of concrete. In the indoor accelerated corrosion test, it was found that the Wetting-drying test caused the highest loss of light rate. In the real sea environmental test, the loss of light rate of the coating in the atmosphere is higher than that in the tidal area, and the color difference is slightly lower. When the loss of light rate is used as the criterion, the grey correlation coefficient between the multi-factor coupling test I and the tidal range test is 0.63, and the maximum acceleration factor during the test is 5.3, indicating a good correlation between the two tests. Through this study, an effective indoor accelerated corrosion test method with good correlation and acceleration characteristics to the loss of light rate of concrete epoxy polysiloxane coating in a real sea environment was obtained.

This study investigates the development of a cost-effective and sustainable dry-shake surface hardener for enhancing the durability of industrial concrete floors. Utilizing locally sourced materials, the research aimed at not only ensuring the hardener's strength and finish but also its economic viability and environmental friendliness. Fourteen unique mixtures were formulated by altering the sand ratios and incorporating superplasticizers to optimize the composition. These mixtures underwent rigorous testing over 7, 14, and 28 days, evaluating their compressive and flexural strengths, flowability, water absorption, and impact resistance. The findings revealed that the modified floor hardener, specifically the FH-12 mixture, exhibited superior performance across all tested parameters. It showed higher compressive and flexural strengths, enhanced impact resistance, and reduced water absorption compared to other variants and commercially available hardeners. Notably, the use of finer coarse sand and the adjustment of superplasticizer quantities significantly contributed to these outcomes. This breakthrough demonstrates the potential of employing locally available materials to create a durable, cost-effective, and environmentally friendly solution for industrial flooring. The study underscores the importance of material characterization and methodical formulation in developing construction materials that meet the dual criteria of performance and sustainability. This option is preferred for its lower environmental impact and compatibility with sustainable practices, contributing to Sustainable Development Goal 9 on industry, innovation, and infrastructure. It highlights the role of floor hardeners in global sustainability efforts.

In this paper the microstructural features of the glass former Fe68Cr8Mo4Nb4B16 coatings are unveiled and related to their electrochemical and tribological responses. The coating was mostly glassy with some embedded borides (M3B2, M2B-tetragonal; M being the metallic elements of the alloy) and ferrite. The tribological behavior of the HVAF coated sample, characterized by a thickness of about 200 µm, ∼6% porosity and a Vickers hardness of 357 HV0.5, was assessed in a sphere-on-plate configuration, revealing a specific wear rate of approximately 5 ×10−4 mm3∙N−1m−1. The wear mechanism was dominated by delamination caused by fragile intersplats. The corrosion resistance of HVAF coatings was evaluated in 0.6 M NaCl solution and compared with the results obtained for the crystalline Fe68Cr8Mo4Nb4B16 ingot, produced by melting in an induction furnace, and for the AISI 1020 steel substrate. The HVAF coating showed satisfactory corrosion resistance compared to the carbon steel substrate and the crystalline ingot, with the highest corrosion potential, Ecorr, values (−533 mVSCE) and the lowest corrosion current density, icorr, (10−6 A∙cm−2) followed by a clear passivation window upon anodic polarization in 0.6 M NaCl solution. Evaluations of HVAF coating showed a higher glassy content compared to the gas-atomized feedstock powders. This suggests that during spraying, certain particles were molten and experienced cooling rates adequate to inhibit crystallization, resulting in the freezing of the supercooled liquid. This phenomenon contributes to the good corrosion resistance observed in the present work and offers an opportunity to enhance the electrochemical behavior of HVAF coatings.

Pomelo (Citrus maxima (Burm. f.) Merr) fresh cut has a highly sensitive fruit and has a short shelf life after peeling. The fruits represent high potentials for local consumption and international export. The objective of the study was to focus on the effects of different concentrations of sodium alginate (1%, 1.5% and 2%) combined with fixed concentrations of calcium chloride (2%) and ascorbic acid (2.5%) to biologically active compounds and allowable microbial content on the surface pomelo fresh cut slices. The results showed that the presence of coating has improved several important quality parameters of the fruit. Specifically, the combination of AL (2%) + AA (2.5%) + calcium chloride (2%) Ascorbic acid (AA) has effectively maintained the total polyphenol content and the total ascorbic acid of the pomelo slice samples, thus exhibiting higher DPPH scavenging activity, as compared to control samples. Furthermore, the pomelo coated with alginate showed good conditions for consumption with minimal microbial degradation and describe good acceptance after 6 days of storage.

Mg-based alloys are used in various industrial sectors due to the unique combination of mechanical and biomedical behaviors. However, they are challenging in terms of corrosion protection and do not produce a protective oxide layer on their surface. The unregulated corrosion rate of these alloys restricts their application. One of the strategies that can provide a protective coating that prevents the direct contact of corrosive media with the substrates is coating on magnesium and its alloys. In recent years, MOF‒MOF-containing coatings have been investigated as a means of protecting various metal alloys against corrosion. The results show that these inhibitors have significantly reduced the rate of metal dissolution by affecting the kinetics of electrochemical reactions and greatly increasing corrosion resistance. So, these coatings are useful for increasing the corrosion resistance of magnesium alloys. Also, the anti-corrosion mechanisms and performance of MOFs in the coating matrix are discussed accordingly. This review article attempts to highlight the importance of MOFs for coating applications and enhancing corrosion resistance.

This study investigated the effect of an edible water-extractable arabinoxylan (WEAX) coating on the postharvest preservation of strawberries and cherries. The WEAX film was prepared using carboxymethyl chitosan (CMCS) film as a control, with thorough characterization of its film properties. Subsequently, strawberry and cherry fruits were submerged in a solution containing edible film-forming materials and left to be stored at room temperature, followed by the analysis of their physicochemical parameters to assess their preservation efficacy. The results show that the WEAX film exhibited enhanced flexibility, superior water vapor permeability, thermal stability, and surface morphology. Furthermore, the implementation of WEAX film effectively mitigated weight loss, decay, color degradation, softening process, ascorbic acid decline, anthocyanin accumulation, and an increase in malondialdehyde content in fruits. Thus, the incorporation of WEAX coating demonstrates its capability in prolonging the shelf life of fruits post-harvest, underscoring its potential in fruit preservation practices.

Along with corrosion, erosion is one of the main causes of damage to civil infrastructures. The continuous impact of fine particles carried by the air produces a deterioration in the elements of these structures. When this damage is significant, these elements are replaced by new ones. In this work, the possibility of extending the useful life of these components by spraying coatings on the damaged areas is proposed. In this sense, repair techniques such as cold spray deposition are possibilities for this purpose. Therefore, this study focuses on evaluating the erosion behaviour of stainless-steel coatings deposited on structural steel. In addition, the erosion results have been correlated with the model proposed by Hutchings, and an energetic interpretation of the erosion process through this model has been proposed. To carry out this study, stainless steel coatings have been deposited on carbon steel substrates to improve their resistance to corrosion. Different spraying temperatures, from 800 °C to 1100 °C, combined with different pressures of the carrier gas, from 40 to 70 bar, have been analysed. The elastic moduli of the coatings, and their stress-strain curve, have been determined by depth sensing indentation tests with Berkovich and spherical tips, respectively. Erosion tests with normal incidence have been programmed to obtain the corresponding erosion rates. From the results of this work, the optimal projection conditions of stainless steel on carbon steel substrates for the repair of civil infrastructures subjected to erosion processes could be identified.

In this study, Vicia villosa protein isolate (VVPI), with a high and valuable protein source, was used to create an edible coating containing ZnO nanoparticles (ZnO NPs) to investigate the effect of active coating on the quality of chicken breast fillets during refrigerated storage. The results showed a low growth rate in total viable count (TVC) and lactic acid bacteria (LAB) in coated samples. Moreover, as ZnO NPs concentration increased, thiobarbituric acid reactive substances (TBARS) decreased in the coated samples. In addition, the acid value and total volatile basic nitrogen (TVB-N) in the coated samples were significantly lower than the control group. Fourier transform infrared (FTIR) spectrum confirmed the chemical interactions of the coating components. Scanning electron microscopy (SEM) showed a homogeneous layer of coating on the surface of the coated chicken meat. Organoleptic indicators including color, smell, texture and overall acceptability were acceptable in all coated samples. These findings showed that the coating based on protein isolate containing ZnO NPs has a good potential to increase the safety and shelf life of chicken meat.

The application of coatings on concrete surfaces serves as a protective shield, guarding the structure against chlorides and averting corrosion of the reinforcement, consequently enhancing its durability. This study investigates the resistance of cement mortar samples to chloride ion penetration when coated with an amine-based carbon dioxide (CO2) solvent. Various factors, including monoethanolamine (MEA) concentrations of 1, 10, and 30 wt%; water-to-cement ratios (w/cm) of 0.35, 0.4, and 0.5; coating timings on day 3 and day 27; and pre-conditioning methods such as air drying, are investigated for their impact on the performance of chloride penetration resistance. Specifically, pre-conditioning significantly enhanced the performance of the coatings, especially in samples with a higher w/cm. Coatings applied at an early stage demonstrated superior resistance to chloride ion penetration compared to those applied later in the curing process. Moreover, solutions with higher concentrations of MEA, capturing more CO2, encouraged the resistance against chloride penetration by reducing capillary macropores within the cement mortar samples. Diffusivity analysis of the coated surface layer confirmed the efficacy of the CO2-dissolved MEA solution as a barrier against chloride ion penetration. Optimal performance was possibly observed in the samples produced by a w/cm of 0.4 and their treatment with more than 10% MEA concentrations.

The introduction of the pulse electroplating method at the beginning of the 21st century and its promising applicability to produce coatings with modified properties have led to its popularity in both scientific and industrial communities. The relationships between the corrosion behavior of pulse-electroplated cobalt-tungsten coatings and their respective chemical composition, morphological and structural properties (that are affected by pulse-electroplating parameters like peak current density and frequency) are investigated in the present study using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), x-ray diffraction spectroscopy (XRD), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques, respectively. The results showed both the coatings' chemical composition and crystal structure can affect their corrosion behaviors; by decreasing pulse frequency (from 5000 to 100Hz) at peak current density of 50 mA/cm2, coatings with higher tungsten content (up to 48.6 wt%), fewer microcracks, coarser crystallite size (up to 57.6 nm) and less lattice microstrain (up to 5.8*10−3) will be deposited which has more corrosion resistance (with corrosion current density of 2.5 μA/cm2). Formation of less defective coatings (with finer crystallite size, up to 52.3 nm, and more lattice microstrain, up to 6.8 × 10−3) including slightly higher tungsten content (up to 49.8 wt%) that have more corrosion resistance occurred at lower applied current densities (25 mA/cm2). So, in the absence of microcracks in the coating's morphology, its tungsten content would be the most effective factor, among other microstructural features, on the coating's corrosion behavior.

Bioactive non-woven dressings can be prepared by dip coating of non-woven cloth in solutions containing bioactive polyethylene bearing pendant arms of polyethylene (PE5000) and modified PEG3400-biomolecules including linear Arg-Gly-Asp (RGD), collagen fragment (Gly-Pro-Hyp)3, laminin-derived peptide (AGQWHRVSVRWGC) (A5G81) and hyaluronic acid (HA). Obtainment of ultimate coating concentration for each type of non-woven cloth is achieved such that the technically demanding bioactive polyethylene does not delaminate from the non-woven cloth itself but is of sufficient quantity for bioactivity. Scanning electron microscopy images show uniform polyethylene deposition on the non-woven cloth. Good water absorption and permeability allow the use of such bioactive polyethylene coated non-woven cloth as wound dressings. Material biocompatibility is demonstrated using in vitro human skin fibroblast assays. In vivo porcine full thickness excisional wound model shows PE5000-coated non-woven cloth can remarkably accelerate skin regeneration to close the wounds faster than clinical gold standard dressing. Thus, the results presented here may provide a promising guide for bioactive polyethylene-modified non-woven materials for wound dressing applications.

For previous studies have neglected the effect of coating thickness and crystal plane on materials deformation during machining, this work is to investigate how coating thickness affect materials deformation with distinct crystal orientation. Using the nanoindentation technique, the mechanical response and plastic deformation of Cu substrate containing FeNiCrCoCu high-entropy alloy coating are investigated. This work provides direct evidence that coating thickness influences the deformation behavior of the workpiece at the atomic level. The results show that the crystal orientation influenced the change of the load–displacement and the deformation behavior, i.e., the mechanical feedback of different crystal planes to the nanoindentation was different, and even the opposite phenomenon occurred with the increase of coating thickness. The anisotropy of the internal phase transition patter and surface morphology deformation in different crystal planes were analyzed by the crystallographic analysis. The work offer microstructure information support for the effect of material anisotropy, coating thickness, and coating atoms on substrate defect-formation, defect/defect interactions, strengthening mechanisms upon loading.

Strawberries rapidly deteriorate postharvest, necessitating effective measures to extend their shelf life. This study focused on developing an eco-friendly chitosan-based protective film for strawberry preservation. Strawberries were treated with a coating solution containing varying concentrations of hawthorn leaf extract (HLE) (0.4%, 0.7%, and 1.0%), 1.5% chitosan (CH), and 1% acetic acid. The results demonstrated that coating strawberry fruit with 1% CH-HLE notably delayed fruit spoilage. In-depth analysis revealed that, compared with the uncoated strawberry fruits, the 1% CH-HLE coating effectively reduced weight loss, the respiration intensity, malondialdehyde (MDA) levels, and superoxide anion (O2·−) production. Additionally, the coated strawberries exhibited improved firmness, total soluble solids (TSS), vitamin C (Vc) content, titratable acidity (TA), and total phenolic compound (TPC) content. The enzyme activities of superoxide dismutase (SOD) and catalase (CAT) in the CH-HLE-coated strawberries were greater than those in their uncoated counterparts. The application of a 1% CH-HLE coating successfully delayed spoilage and extend the shelf life of the strawberries by approximately 4–5 days. These findings suggest that CH-HLE has significant potential as a resource for protecting fruits and vegetables, offering an environmentally sustainable solution for postharvest preservation.

Cavitation-resistant FeMnCrSi coatings were developed in the past years as a cost-effective alternative to Co-containing alloys to increase the lifespan of hydraulic machinery. The effect of different chemical compositions, surface finishing, and post-processing treatments was investigated for various processing techniques, namely: Arc Spraying Process (ASP), High-Velocity Oxy-Fuel (HVOF), High-Velocity Air-Fuel (HVAF), Plasma Transferred Arc (PTA), and Cold Gas Spray (CGS). This works consists of a compilation and review of original and literature results, and discusses the microstructure changes imparted by each type of processing and their impact on the coating properties and cavitation resistance. Low heat input high-velocity processes (HVOF, HVAF, CGS) developed a reduced degree of oxidation and porosity, accounting for a cavitation resistance higher than that of the coatings that ASP processed. In addition, ASP coatings showed reduced cohesive strength, with the oxidized inter-splat interface being a preferential site for crack propagation.

The in situ coating of polymer substrate with polypyrrole, described herein with detailed know-how, represents a novel technique of surface functionalization. The choice of oxidizing agent and the polymerization time both affect the properties of the thin polypyrrole layer. The specific conductivity, free surface energy, thickness, topography, and FTIR spectra of polypyrrole layer were determined. The conductive coatings were further used to functionalize both isotropic and anisotropic electrospun polyurethane nanofibrous mats to show their applicability and study the bioactive effect of both the anisotropy and conductivity together. The morphology of composites was studied by means of atomic force microscopy and scanning electron microscopy. A complex cytocompatibility study was performed, including determining cytotoxicity by optical and fluorescence microscopy, the advanced qualification of cell morphology by cell-image analysis, and a study of stem cell behavior. The results clearly showed the significant impact of substrate modification on cells, especially on fibroblasts while the embryonic stem cells were less affected. This study shows not only the effective way to prepare a thin conducting layer based on polypyrrole but also demonstrates its importance for the fabrication of smart biomaterials.