Search Results (288)

Water supply and sewage drainage pipes have a critical role to play in the provision of clean water and sanitation, and pipe material selection influences infrastructure life, water quality, and microbial communities. Zinc-containing compounds are highly valued due to their mechanical properties, anticorrosion behavior, and antimicrobial properties. However, the effect of zinc salts, such as zinc sulfate heptahydrate and zinc chloride, on biofilm-forming bacteria, including Escherichia coli and Enterococcus faecalis, is not well established. This study investigates the antibacterial properties of these zinc salts under simulated pipeline conditions using minimum inhibitory concentration assays, biofilm production assays, and antibiotic sensitivity tests. Findings indicate that zinc chloride is more antimicrobial due to its higher solubility and bioavailability of Zn²⁺ ions. At higher concentrations, zinc salts inhibit the development of a biofilm, whereas sub-inhibitory concentrations enhance the growth of biofilm, suggesting a stress response in bacteria. zinc chloride also enhances antibiotic efficacy against E. coli but induces resistance in E. faecalis. These findings highlight the dual role of zinc salts in preventing biofilm formation and modulating antimicrobial resistance, necessitating further research to optimize material selection for water distribution networks and mitigate biofilm-associated risks in pipeline systems. Full article

This study investigates the influence of cerium nitrate (Ce(NO₃)₃·6H₂O) content on the performance of Ce(III)/CF/BN/EPN coatings intended for heat exchangers. A series of Ce(III)/carbon fibre (CF)/boron nitride (BN)/epoxy phenolic (EPN) coatings are fabricated with varying concentrations of Ce(NO₃)₃·6H₂O. The results of SEM and EDS show that the dissolution of cerium nitrate in acetone due to the particulate form causes it to be distributed in a diffuse state in the coating. This diffuse distribution does not significantly alter the porosity or structural morphology of the coating. With the increase in cerium nitrate content, both the EIS test results and mechanical damage tests indicate a progressive improvement in the corrosion resistance and self-healing properties of the coatings, while the thermal conductivity (TC) remains largely unaffected. The Ce in the coating reacts with the water molecules penetrating into the coating to generate Ce₂O₃ and CeO₂ with protective properties to fill the permeable pores inside the coating or to form a passivation film at the damaged metal–coating interface, which enhances the anticorrosive and self-repairing properties of the coating. However, the incorporation of Ce(NO₃)₃·6H₂O does not change the distribution structure of the filler inside the coating. As a result, the phonon propagation path, rate, and distance remain unchanged, leading to negligible variation in the thermal conductivity. Therefore, at a cerium nitrate content of 2.5 wt%, the coating exhibits the best overall performance, characterised by a |Z|_0.1Hz value of 6.08 × 10⁹ Ω·cm² and a thermal conductivity of approximately 1.4 W/(m·K). Full article

Nanostructured multilayer anticorrosion coatings offer an effective strategy to mitigate the poor corrosion resistance of aluminum alloys and extend their service life. In this study, four types of Ti/Cr multilayer coatings with varied modulation periods along the growth direction were deposited on 7050 aluminum alloy substrates using direct current magnetron sputtering. The cross-sectional microstructure of the coatings was characterized by scanning electron microscopy (SEM), while their mechanical and corrosion properties were systematically evaluated through nanoindentation and electrochemical measurements. The influence of modulation period distribution on the corrosion resistance of Ti/Cr multilayers was thoroughly investigated. The results show that the average thickness of the Ti/Cr multilayer coatings is 680 nm, the structure is dense, and the coarse columnar crystals are not seen. All Ti/Cr multilayer coatings significantly reduced the corrosion current density of 7050 aluminum alloy by about 10 times compared with that of the substrate, showing good protective effect. Modulation period along the coating growth direction decreases the Ti/Cr multilayer coating surface heterogeneous interface density increases, inhibits the formation of corrosion channels, hindering the penetration of corrosive media, and the other three coatings and aluminum alloy compared to its corrosion surface did not see obvious pore corrosion, showing the most excellent corrosion resistance. Full article

The growing prevalence of bacterial infections and the alarming rise of antimicrobial resistance (AMR) have driven the need for innovative antimicrobial coatings for medical implants and biomaterials. However, implant surface properties, such as roughness, chemistry, and reactivity, critically influence biological interactions and must be engineered to ensure biocompatibility, corrosion resistance, and sustained antibacterial activity. This review evaluates three principal categories of antimicrobial agents utilized in surface functionalization: metal/metaloxide nanoparticles, antibiotics, and phytochemical compounds. Metal/metaloxide-based coatings, especially those incorporating silver (Ag), zinc oxide (ZnO), and copper oxide (CuO), offer broad-spectrum antimicrobial efficacy through mechanisms such as reactive oxygen species (ROS) generation and bacterial membrane disruption, with a reduced risk of resistance development. Antibiotic-based coatings enable localized drug delivery but often face limitations related to burst release, cytotoxicity, and diminishing effectiveness against multidrug-resistant (MDR) strains. In contrast, phytochemical-derived coatings—using bioactive plant compounds such as curcumin, eugenol, and quercetin—present a promising, biocompatible, and sustainable alternative. These agents not only exhibit antimicrobial properties but also provide anti-inflammatory, antioxidant, and osteogenic benefits, making them multifunctional tools for implant surface modification. The integration of these antimicrobial strategies aims to reduce bacterial adhesion, inhibit biofilm formation, and enhance tissue regeneration. By leveraging the synergistic effects of metal/metaloxide nanoparticles, antibiotics, and phytochemicals, next-generation implant coatings hold the potential to significantly improve infection control and clinical outcomes in implant-based therapies. Full article

Corrosion is a major issue in many industries, leading to material degradation, increased maintenance costs, and safety hazards. Conventional protective coatings frequently rely on hazardous chemicals, which has driven demand for environmentally friendly materials that can enhance the durability of infrastructure. The present study investigates the structural, mechanical, anticorrosive, and tensile properties of a novel polymer composite based on tannic acid-benzoxazine monomer (TA-BZ), reinforced with epoxy resin and zinc oxide (ZnO) nanoparticles. The composite formulations are designated as Epoxy-TA-BZ1-ZnO (A), Epoxy-TA-BZ2-ZnO (B), and Epoxy-TA-BZ4-ZnO (C). The objective of this research is to develop a sustainable material system with improved anticorrosive and mechanical performance. The composites were synthesized through the crosslinking of TA-BZ with epoxy resin and the incorporation of ZnO nanoparticles, known for their corrosion-inhibiting properties and contributions to tensile strength. The materials were evaluated using Fourier Transform Infrared (FT-IR) spectroscopy, Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), potentiodynamic polarization techniques, and tensile testing. Among the tested formulations, Epoxy-TA-BZ4-ZnO exhibited outstanding anticorrosive performance, achieving a minimal corrosion rate of 0.06 mm/year. This performance is attributed to the favorable dispersion of ZnO nanoparticles at 5 wt%, which serve as effective barriers to corrosive agents under the conditions studied. These findings highlight the potential of TA-BZ-based composites as environmentally sustainable alternatives to conventional coatings in corrosion-sensitive applications. Full article

To assess how the graphite nanosheet size affects the performance of hydrophilic coatings, graphite nanosheets of various sizes were added to a mullite/kaolin epoxy (EP) coating. The experimental results indicated that the mullite/kaolin EP coating enriched with graphite nanosheets (1.01 ± 0.1 μm) exhibited the highest impedance value of 9.18 × 10⁷ Ω cm², demonstrating the best performance after 2880 h of exposure to salt spray. This implies exceptional wear resistance. Appropriately sized graphite nanosheets can create excellent nanonetworks that cover micropores, which cannot prevent the diffusion of corrosive media and provide excellent mechanical properties to coatings. The results of this study serve as a reference for the industrial application of graphite anticorrosive coatings. Full article

Guardrail concrete in cold regions frequently suffers from corrosion due to icing and solutions, significantly shortening the service life of the guardrail. This paper proposed a cement-based composite coating for concrete protection. The hydrophobic agent was synthesized using nano-silica, tetraethyl orthosilicate and perfluorodecyltrimethoxysilane and used for coating modification as an additive or by impregnation. Also, a commercial hydrophobic agent was used for comparison. The modified coating was characterized by wettability, mechanical properties, chemical stability and icephobicity tests. The results showed that the coating prepared with the synthetic hydrophobic agent presented a higher contact angle than that prepared with the commercial one during the above tests. Moreover, it featured excellent icephobicity by effectively delaying the time of icing on concrete and reducing the icing mass and ice adhesion strength. In addition, the hydrophobic agent used by impregnation was a better choice for concrete surface protection. Chemical composition and morphology analysis of the coating showed that hydrophobicity and icephobicity were mainly attributed to F-containing functional groups and rough structure with low surface energy. This study provided an application potential of modified cement-based composite coating for anti-/de-icing of guardrail concrete. Full article

Silicon oxycarbide coatings are the subject of research due to their exceptional optical, electronic, anti-corrosion, etc., properties, which make them attractive for a number of applications. In this article, we present a study on the synthesis and characterization of thin SiOC:H silicon oxycarbide films with the given composition and properties from a new organosilicon precursor octamethyl-1,4-dioxatetrasilacyclohexane (²D₂) and its macromolecular equivalent—poly(oxybisdimethylsily1ene) (POBDMS). Layers from ²D₂ precursor with different SiOC:H structure, from polymeric to ceramic-like, were produced in the remote microwave hydrogen plasma by CVD method (RHP-CVD) on a heated substrate in the temperature range of 30–400 °C. SiOC:H polymer layers from POEDMS were deposited from solution by spin coating and then crosslinked in RHP via the breaking of the Si-Si silyl bonds initiated by hydrogen radicals. The properties of SiOC:H layers obtained by both methods were compared. The density of the cross-linked materials was determined by the gravimetric method, elemental composition by means of XPS, chemical structure by FTIR spectroscopy, and NMR spectroscopy (¹³C, ²⁹Si). Photoluminescence analyses and ellipsometric measurements were also performed. Surface morphology was characterized by AFM. Based on the obtained results, a mechanism of initiation, growth, and cross-linking of the CVD layers under the influence of hydrogen radicals was proposed. Full article

As one of the decay-resistant woods, Korean pine is widely used in the construction industry. However, even the most corrosion-resistant wood is still susceptible to decay under the right humidity and temperature conditions. In this study, Bacillus amyloliquefaciens (B. amyloliquefaciens) bacterial liquid and filter bacterial solution were prepared for the anti-corrosion treatment of Korean pine wood, aiming to improve its decay-resistant property. Through the plate confrontation test, it was discovered that B. amyloliquefaciens AW3 could significantly inhibit the growth of Fomitopsis pinicola (F. Pinicola). The results of mass loss rate, mechanical properties test, XRD, FTIR and SEM analysis showed that the preserved Korean pine wood had significant improvement in various properties compared with the decayed wood, which was manifested in the significant reduction of mass loss, improvement of mechanical properties, and increased wood cellulose diffraction peak intensity. There is no mycelium infection of F. pinicola in Korean pine wood, and the antiseptic liquid can penetrate into the wood evenly, which plays an effective antiseptic role. The B. amyloliquefaciens bacterial liquid exhibited superior preservative performance compared to the B. amyloliquefaciens filter bacterial solution. In conclusion, B. amyloliquefaciens, as an efficient and environmentally friendly biological preservative, holds broad application prospects in improving the anti-corrosion performance of Korean pine wood. Full article

This review article focuses on providing an accumulated knowledge on state-of-the-art composite polymer coating technologies that are studied for corrosion protection. A specific focus has been given to epoxy resin-based composite systems, considering their wide use due to remarkable chemical resistance, excellent adhesion to substrate, thermal stability, and mechanical strength. The addition of various functional polymers to the epoxy matrix has spurred significant advancements in the prevention of corrosion. Light has been shed on the epoxy resin composite systems that are produced by blending with functional polymers like conductive polymers, hydrophobic polymers, etc., and nanofillers. In many cases, the formation of a passive layer at the metal/polymer interface was aided by the addition of such a functional polymer and nanofiller to the epoxy matrix. As a result, corrosive ions are prevented from penetrating by the physical barrier that composite coatings provide. Comparable blends of epoxy and polyamide, epoxy and polyester, and epoxy/poly(vinyl alcohol) and epoxy/polyurethane have superior adhesion, wear, barrier, and anticorrosion properties due to the fine dispersion of nanocarbon and inorganic nanoparticles. The several strategies used to prevent metals from corroding are covered in this review article. Full article

Corrosion-resistant coatings are essential for prolonging the lifespan of metal structures, yet conventional formulations often lack sufficient mechanical strength and chemical durability. This study focuses on the development of polyurethane/epoxy hybrid coatings (PUAE) with varying epoxy resin content (5%, 10%, and 15% by weight) to enhance performance. The hybrid films demonstrated improved mechanical properties with increasing epoxy content, including a rise in tensile strength from 39.1 MPa (PUA) to 86.3 MPa (PUAE15) and adhesion from 2.5 MPa to 8.3 MPa. Hardness also increased from 69 Shore A to 98 Shore A, while elongation at break decreased from 158% to 95%, indicating a shift toward a stiffer material. The thermal stability, assessed by TGA, showed higher degradation temperatures, with PUAE15 reaching a maximum decomposition temperature of 390 °C, compared to 320 °C for pure polyurethane. Viscosity at 5 rpm increased from 12.300 mPa·s to 18.563 mPa·s, and the contact angle improved from 105° to 149°, highlighting enhanced hydrophobicity. PUAE15 also displayed superior resistance to solvents and acidic environments. These results affirm that epoxy content significantly influences the structural, mechanical, and corrosion-resistant properties of polyurethane-based coatings, making PUAE15 a promising candidate for advanced anticorrosive applications. Full article

Laser surface texturing (LST) is a versatile method for enhancing material surface properties, offering high precision and flexibility for surface modification. This review comprehensively examines the application of laser texturing technology for surface protection and functional regulation of aluminum alloys, focusing on wettability, anti-icing, corrosion resistance, and wear resistance. It highlights recent progress in laser surface patterning techniques, describing the principles and attributes of methods such as direct laser writing, laser interference patterning, and laser shock treatment. The influence of laser intensity, scanning velocity, and texture spacing on surface topography is discussed thoroughly. Mechanisms of wettability control via laser surface texturing are summarized, emphasizing the key factors required to achieve superhydrophobic or hydrophilic properties through texture design. Advancements in enhancing anti-icing, anti-frost, anti-fouling, and anti-corrosion properties through multi-scale textures and their synergistic effects with functional coatings are analyzed. Additionally, the enhancement of wear resistance and friction performance under both dry and lubricated conditions is reviewed, with a focus on how the geometry and arrangement of textures affect the coefficient of friction and wear rate. Finally, the paper addresses challenges and future directions, including process optimization, scalability, and the integration of LST with advanced coatings to maximize its potential in aluminum alloy applications. Full article

The ongoing electrification process also requires improvements in the efficiency of power transmission devices, such as transformers, the main part of which is the magnetic core. Despite great progress in the development of core material, losses and audible noise during their operation is still a critical issue to be solved. Currently, a magnetic material used to produce the transformer core is amorphous steel, which is gaining popularity. Compared to traditionally used grain-oriented silicon electrical steel, a significantly larger number of very thin amorphous ribbons is needed to produce the core, which is due to the fact that they are about an order of magnitude thinner, making mechanical stability a challenge. The presented article describes the preparation of a hybrid binder for amorphous steel based on the two types of silanes, tetraethyl orthosilicate and 1,2-bis(triethoxysilyl)ethane, for which their anticorrosive character and good dielectric properties were confirmed. Using the obtained binders, model toroidal cores were produced and their magnetic and acoustic properties were tested. The obtained results indicate that the applied silane-based hybrid binders improved important functional properties by reducing the magnetic no-load losses and audible noise. Full article

Bimetallic-clad pipes demonstrate exceptional advantages in transporting corrosive oil and gas through the combination of the load-carrying capacity of the base material and the anti-corrosive function of the thin layer of corrosion-resistant alloy. This study investigates the mechanical properties of 24-inch X65 + Alloy625 metallurgically clad pipes through experimental tests and finite element analysis. Uniaxial tensile testing with digital image correlation reveals uniform deformation between the base and clad layers until interfacial failure initiates at an average strain threshold of 34.17%. Microstructural characterization shows continuous metallurgical bonding, with the X65 layer exhibiting polygonal ferrite and bainitic phases, contrasting with the austenitic equiaxed grain structure of Alloy625. In terms of numerical modeling, finite element analyses that consider both initial geometric imperfections and manufacturing-induced residual stresses are performed to evaluate the bending response of the clad pipe. The effect of initial ovality and residual stresses on its bending capacity is also studied. Full article

Epoxy resin (EP) is a candidate material for offshore oil platform safety signs due to its excellent corrosion resistance property. However, fabricating EP with good anti-corrosion as well as mechanical properties remains a significant challenge. Here, we report a new modification strategy to simultaneously improve the corrosion resistance and mechanical performance of EP by coupling it with KH550 silanized graphene oxide (KGO) and KH550 silanized glass fiber (KGF). KGO and KGF were grafted onto EP to obtain the modified EP material, i.e., KGO/KGF/EP composites and were characterized by FITR, XRD, SEM, and TGA to confirm the successful synthesis of the composites. It is shown that the tensile strength and adhesion strength of KGO/KGF/EP were 85.5 MPa and 16.0 MPa, which are 10.3% and 23.1% higher than KGO/GF/EP. Compared with KGF/EP, the corrosion potential increased by 9.9% and the corrosion rate decreased by 98.8%. Moreover, fluid–structure coupling simulation indicated the maximum stress of the material was within the criteria under extreme wind speeds, demonstrating its great potential for offshore oil platform safety sign applications. Full article