Search Results (350)

Ocean energy is an abundant, eco-friendly, and renewable energy resource that is useful for powering sensor networks connected to the maritime Internet of Things (MIoT). These sensor networks can be used to measure different marine environmental parameters that affect ocean infrastructure integrity and harm marine ecosystems. This ocean energy can be harnessed through hybrid nanogenerators that combine triboelectric nanogenerators, electromagnetic generators, piezoelectric nanogenerators, and pyroelectric generators. These nanogenerators have advantages such as high-power density, robust design, easy operating principle, and cost-effective fabrication. However, the performance of these nanogenerators can be affected by the wear of their main components, reduction of wave frequency and amplitude, extreme corrosion, and sea storms. To address these challenges, future research on hybrid nanogenerators must improve their mechanical strength, including materials and packages with anti-corrosion coatings. Herein, we present recent advances in the performance of different hybrid nanogenerators to harvest ocean energy, including various transduction mechanisms. Furthermore, this review reports potential applications of hybrid nanogenerators to power devices in marine infrastructure or serve as self-powered MIoT monitoring sensor networks. This review discusses key challenges that must be addressed to achieve the commercial success of these nanogenerators, regarding design strategies with advanced simulation models or digital twins. Also, these strategies must incorporate new materials that improve the performance, reliability, and integration of future nanogenerator array systems. Thus, optimized hybrid nanogenerators can represent a promising technology for ocean energy harvesting with application in the maritime industry. Full article

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

In this paper, a series of polyaniline (PANI)/Ti₃C₂ MXene composites (PMCs) with a biomimetic structure were prepared and employed as an anticorrosion coating application. First, the PANI was synthesized by oxidative polymerization with ammonium persulfate as the oxidant. Then, 2D Ti₃C₂ MXene nanosheets were prepared by treating the Ti₃AlC₂ using the optimized minimally intensive layer delamination (MILD) method, followed by characterization via XRD and SEM. Subsequently, the PMC was prepared by the oxidative polymerization of aniline monomers in the presence of Ti₃C₂ MXene nanosheets, followed by characterization via FTIR, XRD, SEM, TEM, CV, and UV–Visible. Eventually, the PMC coatings with the artificial biomimetic surface structure of a macaw feather were prepared by the nano-casting technique. The corrosion resistance of the PMC coatings, evaluated via Tafel polarization and Nyquist impedance measurements, shows that increasing the MXene loading up to 5 wt % shifts the corrosion potential (E_corr) on steel from −588 mV to −356 mV vs. SCE, reduces the corrosion current density (I_corr) from 1.09 µA/cm² to 0.035 µA/cm², and raises the impedance modulus at 0.01 Hz from 67 kΩ to 3794 kΩ. When structured with the hierarchical feather topography, the PMC coating (Bio-PA-MX-5) further advances the E_corr to +103.6 mV, lowers the I_corr to 7.22 × 10⁻⁴ µA/cm², and boosts the impedance to 96,875 kΩ. Compared to neat coatings without biomimetic structuring, those with engineered biomimetic surfaces showed significantly improved corrosion protection performance. These enhancements arise from three synergistic mechanisms: (i) polyaniline’s redox catalysis accelerates the formation of a dense passive oxide layer; (ii) MXene nanosheets create a tortuous gas barrier that cuts the oxygen permeability from 11.3 Barrer to 0.9 Barrer; and (iii) the biomimetic surface traps air pockets, raising the water contact angle from 87° to 135°. This integrated approach delivers one of the highest combined corrosion potentials and impedance values reported for thin-film coatings, pointing to a general strategy for durable steel protection. 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 development of power engineering requires the introduction of new materials and technologies to improve the quality and durability of products. One promising direction is the creation of heat-protective coatings for the protection of working surfaces of turbine blades of gas turbine engines operating at temperatures up to 1000–1200 °C. Intermetallic coatings based on iron aluminides (Fe₃Al, FeAl) have high resistance to oxidation due to the formation of an oxide layer: Al₂O₃. However, their application is limited by brittleness due to the so-called third element effect, which can be reduced through alloying with chromium. In this study the processes of formation of Fe–Al–Cr intermetallic coatings produced by air plasma spraying and the mechanisms affecting their stability at high temperatures were investigated. Experimental studies included the analysis of the microhardness, wear resistance, and corrosion resistance of coatings, as well as their phase composition and microstructure. The results showed that the optimization of sputtering parameters, especially in the FrCrAl (30_33) mode, promotes the formation of a coating with improved tribological and anticorrosion characteristics, which is associated with its dense and uniform structure. These data have an important practical significance for the creation of wear-resistant and corrosion-resistant coatings applicable in power engineering. 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

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

Green coating research and development has taken a new turn in recent years because of the combination of nanomaterials and anticorrosive and antifouling coatings. Because of its distinct physicochemical characteristics, graphene, a novel two-dimensional material, exhibits significant promise in anticorrosive and antifouling coatings. The fundamental characteristics of graphene are presented in this paper along with an overview of its uses in anticorrosive films, anticorrosive coatings, and antifouling coatings. The mechanism underlying graphene anticorrosive and antifouling coatings is also presented, along with the difficulties associated with them and their potential future development. It seeks to serve as a resource for the study and use of anticorrosion and antifouling coatings based on graphene. 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

The novel pyridine oxime-based complexing agents 2-pyridinecarboxaldehyde oxime, 2-acetylpyridine ketoxime and 2-pyridine amidoxime were synthesized for alkaline Zn-Ni alloy electrodeposition, outperforming conventional citrate/TEPA systems in corrosion resistance and microstructural control. The N,O-bidentate chelation mechanism governs metal ion reduction kinetics via diffusion-limited pathways, enabling γ-phase Ni₅Zn₂₁ intermetallic formation and nanocrystalline refinement. Electrochemical and microstructural analyses demonstrate suppressed random nucleation and hydrogen evolution side reactions, leading to enhanced charge transfer resistance and reduced corrosion current density. Notably, 2-pyridine amidoxime achieves ultrasmooth surfaces through defect-free nanocluster growth, while 2-pyridinecarboxaldehyde oxime maximizes γ-phase crystallinity. The synergy between grain boundary density and surface integrity establishes a dual protection mechanism combining barrier layer formation and active dissolution suppression. This work advances microstructure engineering via coordination chemistry, offering a breakthrough over traditional zincate electroplating for high-performance anti-corrosion coatings. 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