This study examined graphene-embedded polypyrrole (PPy) composites with varying weight ratios of PPy to graphene (100 : 0, 90 : 10, 80 : 20, and 70 : 30). The composites were prepared via in situ chemical oxidative polymerization. They were thoroughly analyzed for their electrical, electrochemical, structural, thermal, and optical properties. Among the different compositions, the 80 : 20 ratio demonstrated the highest specific capacitance, energy density, and cycling stability. For this optimal composition, the sheet resistance was measured at 448.2 Ω/sq, optical transparency was at 47
Bone fractures occurring in various parts of the body often require the use of implants to restore the lost structural integrity and function of the affected area. Additionally, joint-related disorders such as rheumatoid arthritis and osteoarthritis commonly demand surgical interventions, including the replacement of hip and knee joints. In these scenarios, biomaterial implants play a vital role in stabilizing fractures or replacing damaged tissues. HAp is a well-known bio-ceramic recognized for its excellent biocompatibility and bioactivity. Its structure closely resembles that of natural bone, making it widely used as an implant material for hard tissue applications. However, despite these advantageous properties, HAp suffers from several limitations, including low mechanical strength, poor structural stability, susceptibility to microbial colonization over time, and limited degradability. Metals and synthetic polymers are the predominant classes of biomaterials used, chosen for their ability to replicate the mechanical performance of natural bone. Frequently used metallic biomaterials include stainless steel and titanium due to their excellent strength and biocompatibility. On the other hand, synthetic polymers like polydopamine (PDA) are favored for their flexibility and compatibility with bodily tissues. This review focuses on a comparative evaluation of metallic and polymeric implant materials for load-bearing bone applications and suitability for enduring the physiological mechanical loads within the human body.
The interaction of sulfonate groups of an MK-40 cation exchange membrane with water molecules during hydration was analyzed using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The obtained spectra show the presence of two forms of sulfonate groups—acidic and salt, the symmetry of which remains virtually unchanged during the process of swelling and cation exchange. Water surrounding the sulfonic acid groups forms an electrical double layer (EDL), creating three phases: (1) bound water, (2) water localized in the interphase space between bound water and water at the zero potential boundary (diffuse layer), and (3) free water between the zero potential boundaries of the EDL. The second type of water is water whose hydrogen bonds are formed by the electric field of a cation in an anion–cation pair. Increasing water saturation leads to a weakening of the interaction of the Na+ cation on the SO_3^ - group with possible rupture of an ion pair and the formation of symmetrical micelles with a cation core (Na+), which significantly affects the cation exchange process. Experimental data from TGA and DSC showed that the mechanism of water loss during thermolysis of membrane samples in the range from 50 to 450°C completely coincide with the conclusions made on the basis of IR spectroscopy data.
This study investigated the activation of potassium feldspar by sodium hydroxide roasting and the preparation of spherical Y-type zeolites using silicon-extraction residues as the aluminum and silicon source. Single-factor experiments determined the optimal process conditions: the molar ratio of alkali to ore was 4, the roasting temperature was 550°C, and the roasting time was 2 h. Under these conditions, the SiO2 extraction rate reached 97.99
Binders play a crucial role in binder jetting, as they determine printing process stability, geometric accuracy, and the properties of the final products. Analysis of modern research shows that the basis of binders is usually water, organic solvents or their mixtures in various proportions, and all three types are of almost equal importance depending on the specific application. Particular attention is paid to the rheological characteristics of binders, which determine the printability, as well as the binder removal process, which affects the phase composition of the resulting products. This review proposes a classification of binders for binder jetting, categorizing them into four types: liquid organic, solid, nanoparticle-filled, and reactive. Further development of binder jetting technology and expansion of its industrial application directly depend on research aimed at creating new binder systems that meet growing industrial requirements. An integrated approach combining chemical synthesis and materials science analysis opens up prospects for the development of specialized formulations adapted to specific classes of materials and functional requirements.
The present work focuses on the results of the study of adsorption of carbon dioxide and nitrogen onto the synthesized metal-organic framework polymer (MOF) ZrBDC-NH2. The isotherms were recorded at temperatures of 243, 273, 293, and 333 K within the pressure range of 0 to 120 kPa. The isotherms of individual gas adsorption were calculated using the Dubinin–Radushkevich (D–R) equation within the framework of the theory of volume filling of micropores (TVFM). The IAST method was used to predict the adsorption of the binary CO2/N2 mixture with the gas component ratio of 0.04/99.96 vol
Corrosion presents significant issues in both everyday life and industrial applications; effective corrosion management solutions are critical for lowering costs and improving safety. The present work is the first study to computationally investigate the potential of novel 3-(2-((E)-2-((E)-3-((Z)-2-(3-(2-carboxyethyl)-1,1-dimethyl-1,3-dihydro-2H-benzo[e]indol-2-ylidene)ethylidene)-2-chlorocyclohex-1-en-1-yl)vinyl)-1,1-dimethyl-1H-benzo[e]indol-3-ium-3-yl)propanoate (MK245DYE) as corrosion inhibitors. The current work is innovative in that it uses a some of methods to predicate computational investigations: GaussView 6.0 was applied. DFT/B3LYP/6-311G(d,p) level of theory used to compute electronic stracture, global reactivate parameters, adsorption energy, electron charge transfer from molecules to metals, and charge density: topological analyses, the Multiwfn program used to shows LOL, ELF, DOS, NCI, RDG to calculating the electron density: Monte Carlo (MC) simulations in acidic environment (250H2O, 8 (Cl– and H3O+), and dry environment on the Fe (110) surface. In LOL maps, the white circles surrounding the middle of the H atoms point out that the electron density is higher than the highest limit of the color scale (0.8). The data MC suggests that the acidic environment is substantially more negative adsorption energy –7577.0 kcal/mol for corrosive than the dry environment. The results show that these novel compounds have promising inhibitory properties, underlining their potential for practical applications in corrosion prevention.
To investigate the regulation mechanism of deep cryogenic treatment (DCT) after artificial aging on the properties of ultra-strong and highly alloyed Al–Zn–Mg–Cu–Zr–Sc aluminum alloy, this study systematically examined the influence of DCT duration on the alloy’s microstructure, mechanical properties, and corrosion resistance. The results show that DCT can significantly increase the dislocation density of the alloy and enhance the dislocation strengthening effect, among which the DCT-9 scheme exhibits the optimal strengthening effect. However, DCT has no significant impact on the morphology, size, quantity of coarse second phases or the average grain size of the alloy. In terms of mechanical properties, DCT can improve the alloy’s hardness, yield strength, and tensile strength, with a slight decrease in plasticity. The DCT-9 alloy achieves the optimal comprehensive mechanical properties, with a yield strength, tensile strength, and elongation after fracture of 808.2, 837.6 MPa, and 2.9
An investigation gives insights into the nature of the transition metal (TM)–boron electronic interaction in boron-bearing intermetallics and its effects on surface hydrogen adsorption and energy storage activity. This article wants to investigate the hydrogen storage increase through doping of Cr, Ni, Zn, Mo, Pd, Cd on the boron nitride nanocage. Based on NQR analysis, nickel, and palladium with atomic charges of 0.2658 and 0.3266 C on the complexes of Ni@BN and Pd@BN, respectively, have shown much more tendency for H2 adsorption than other complexes. The results of NMR spectroscopy have exhibited that the efficiency of electron admitting for implanting atoms on the [Cr, Ni, Zn, Mo, Pd, Cd]@BN through H2 adsorption can be ordered as: Ni > Pd ≫ Cr > Mo ≈ Zn > Cd. Regarding thermodynamic properties, it was indicated that for hydrogen sites in H2 molecules, the consistencies of heteroclusters of decorated elements of Cr, Ni, Zn, Mo, Pd, Cd can be brought up as: Ni@BN > Pd@BN ≫ Cr@BN > Mo@BN ≈ Zn@BN > Cd@BN complexes. In addition, the hydrogen adsorption on transition metals doping BN heterocluster has been estimated through density of states analysis of total density of state (TDOS), partial density of states (PDOS), overlap partial density of states (OPDOS) and localized orbital locator analysis (LOL). Thus, the transition metal implanted BN can be used for designing novel materials for H2 adsorption and sensing applications. Strong hybridization between the d orbitals of TM and the sp orbitals of boron exists in a family of six TM–boron intermatallics (TM@B), and hydrogen atoms adsorb more weakly to the metal-terminated intermetallic surfaces than to the corresponding pure metal surfaces.
Ni—Cr—ZrO2 nano-composites are electrodeposited from sulfate electrolyte and a comparison is made with Ni—ZrO2 in terms of structure and properties. The coatings have been electrodeposited on cylindrical parts made of copper. The influence of the various experimental conditions has been considered by varying the concentration. The different electrodeposited layers are characterized by various analytical techniques: adhesion quality, corrosion resistance in sea water, Vickers microhardness, X-ray diffraction, morphology by scanning electron microscopy Followed by a microanalysis (EDX). The coatings prepared have a very good adhesion, are more resistant to corrosion, have a good hardness, an homogeneous and compact morphology and exhibit a high degree of co-deposition of particles incorporated in the nickel-chromium matrix.
This study investigates the corrosion behavior of newly produced quinary lead-free solder alloys, specifically Sn–2Ag–0.5Cu–1Bi–xAl (SACBi–xAl) with varying aluminum contents (x = 0.05, 0.1, 0.3, 0.5, and 0.6 wt
The corrosion inhibitive efficiencies of naproxen sodium (NAP) and ibuprofen sodium (IBU) for copper in 0.5 M HCl solution were investigated by Tafel polarization method. Corrosion potential, corrosion current density, cathodic and anodic Tafel slopes, and inhibition effectiveness were determined. The experimental results suggest that NAP is a good corrosion inhibitor at different concentrations whereas IBU shows low-efficiency values. The reactivity of NAP and IBU was analyzed through quantum chemical calculations based on density functional theory (DFT) in gas and aqueous phases to explain the different efficiencies of these compounds as corrosion inhibitors both in the neutral and protonated forms. Electrophilic and nucleophilic sites of molecules were investigated by Fukui functions.
The modifying effect of a polyfluorinated amine synthesized by bisalkylation of tris(2-aminoethyl)amine with a polyfluorinated alcohol on the structure and properties of polyurethane elastomers is studied. The structure of the modified polyurethane is studied by diffraction and small-angle X-ray scattering, NMR spectroscopy, and sol–gel analysis. It is shown that introducing the modifier at the stage of migration polymerization of isocyanate and polyol favorably affects the strengthening of the obtained fluoropolymer, increase in the hydrophobicity of the obtained coatings, and their stability under the conditions of photochemical degradation and action of aggressive environments.
The presence of chloride ions in a harsh acidic environment poses significant corrosion threats to metals. Zeolitic imidazole frameworks (ZIFs) emerge as a promising candidate for corrosion protection, owing to their favorable microstructural features and corrosion inhibiting imidazole ligands. In this study, we employed ZIF-67 in conjunction with 1,10-phenanthroline (Phen), a material that exhibits both corrosion sensing and inhibition properties, as nano-fillers for anticorrosive water-borne acrylic epoxy coating (EA). The morphology, composition and microstructure of the performed ZIF-67@Phen nanoparticles and the hybrid ZIF-67@Phen/EA coating systems were characterized, and the protective performance of the coatings was evaluated through electrochemical tests. Simultaneously, the impact of varying ratios of ZIF-67 and Phen in ZIF-67@Phen complexes on the anticorrosion properties of the coatings was also examined. The ZIF-67@Phen/EP coating with the ratio of ZIF-67 and Phen of 0.12, demonstrated superior active inhibition properties and conferred long-term protection on the metal substrate through the synergistic effect of Phen and ZIF-67. This multifunctional coating that possesses both active inhibition and stable and durable anticorrosive capabilities, represents an efficacious approach for the protection of metals against corrosion.
Hydrogen transportation pipelines require steels with enhanced hydrogen barrier properties. This study aims to develop a composite coating with integrated functions of corrosion resistance and hydrogen barrier. Firstly, a dense black oxide layer was chemically formed on X65 pipeline steel at room temperature by a modified blackening process. Then, the traditional epoxy resin was applied onto the surface of black oxide layer, obtaining a novel black oxide/epoxy resin composite coating. For the blackening process, the effects of surface pretreatment methods (untreated, polished, sandblasted) and blackening solution pH (1.5, 2.5, 3.5) on the microstructure, corrosion resistance and hydrogen barrier performance were investigated, as well as the adhesion strength of composite coating. Results show that corrosion resistance and hydrogen barrier performance of coatings depended on both blackening solution pH and pretreatment method, with polished substrates and pH 2.5 yielding optimal results. Additionally, the black oxide layer served as an effective adhesion-promoting interlayer, enhancing the bonding and durability of the composite coating. This novel black oxide/epoxy composite coating system offers valuable insights for designing hydrogen barrier coatings for pipeline steels.
The macrocyclic octaaza-bis-α-diimine complex was synthesized through the condensation of dione dihydrazone with an acid. Through the reaction of this complex with lanthanide chloride, [Ln(C36H34N10O4)Cl] complexes were formed, where Ln represents La(III), Ce(III), or Yb(III). Thorough spectral characterization was conducted on both the ligand and its respective metal complexes. Infrared spectroscopy, energy-dispersive X-ray spectroscopy (EDS), and elemental analysis were employed to confirm the successful synthesis of the complexes and accurately identify their constituent elements. The stability of the metal-ligand complex was evaluated through thermogravimetric analysis (TGA). Additionally, fractal analysis was performed on the ligand lanthanide (III) complex. The cube counting method revealed that the fractal dimension (Df) value followed the order of La > Ce > Yb, indicating that lanthanum exhibited the highest surface roughness. Consequently, La demonstrated the greatest antibacterial and antifungal properties, attributable to its rough surface. The enhanced biological activity of the La(III) complexes can be attributed to the presence of surface roughness. Furthermore, due to the structural modification of the metal complexes into nanostructures, the antimicrobial activities exhibited by the metal complexes surpassed those of the ligands. Notably, the La(III) nanosized complex displayed excellent antimicrobial activity. The results of these evaluations are presented and discussed in detail within this paper.
The influence was studied of argon consumption on the structure and properties of Ti–Nb–B–C coatings obtained by magnetron sputtering of a ceramic heterophase target of the composition (Ti,Nb)B2–40
Sulfate-reducing bacteria (SRB) are major contributors to microbiologically influenced corrosion (MIC) in oil and gas production systems due to their ability to generate hydrogen sulfide (H2S) during dissimilatory sulfate reduction. Although SRB have been extensively studied in reservoirs and produced waters, oil-contaminated soils remain insufficiently investigated despite their potential to serve as long-term microbial sources of sulfide and corrosion activity. This study investigates the occurrence, abundance, metabolic activity, and corrosion-related effects of sulfate-reducing bacteria in oil-contaminated soil samples collected from the Bibi-Heybat OGPD. Soil samples were enriched and cultivated under anaerobic conditions using selective Postgate B medium. SRB abundance was determined by culture-based methods, sulfide production was quantified iodometrically, and the corrosive aggressiveness of soil-derived aqueous extracts was evaluated gravimetrically using carbon steel coupons. Molecular identification of representative isolates was carried out by partial 16S rRNA gene sequencing. The results demonstrated significant SRB populations ranging from 104 to 106 cells g–1 dry soil, with Desulfovibrio species dominating the microbial community. Active sulfate reduction was confirmed by sulfide accumulation reaching approximately 400 mg L–1 after 7 days of incubation. Higher SRB abundance was associated with slightly alkaline soil pH and increased corrosion rates, indicating that oil-contaminated soils represent an important and previously underestimated corrosion risk factor in oilfield environments. The obtained results contribute to understanding the microbial diversity and corrosion potential of subsurface environments associated with offshore oil extraction.
Copper electroplating is widely employed to enhance the corrosion resistance of steel substrates in various industrial applications. However, conventional cyanide‑based electrolytes present severe environmental and safety challenges due to the high toxicity of free cyanide ions. In recent years, significant research efforts have been directed toward developing environmentally benign, non‑cyanide copper plating processes. This study presents a systematic comparison of four promising non‑cyanide plating systems—citric acid–tartrate, citrate, HEDP (1‑hydroxyethylidene‑1,1‑diphosphonic acid), and electroless copper plating on low‑carbon steel substrates. The corrosion‑protective performance of the resulting coatings was thoroughly evaluated using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. Coating thickness, adhesion, and surface morphology were also characterized to correlate microstructural features with electrochemical behavior. Results indicate that the citric acid–tartrate plating bath produces the most uniform and adherent coatings with the highest thickness ( 8.15 µm), leading to the lowest corrosion current density (3.98 µA cm–2) and the most noble corrosion potential (–293 mV). HEDP‑plated samples exhibited moderate protection, while citrate‑plated and electroless‑plated coatings showed comparatively inferior performance. The optimized parameters for citric acid–tartrate plating were determined as: bath temperature 40°C, current density 1.5 A dm–2, pH 8.5–9, and plating time 30–40 min. This work not only identifies the most effective cyanide‑free copper plating process but also elucidates the underlying electrochemical mechanisms governing corrosion protection, providing a practical framework for industrial adoption of safer and more sustainable plating technologies.
In this study, TC4 (Ti–6Al–4V) titanium alloy was employed as the substrate, and micro-arc oxidation (MAO) coatings were fabricated in electrolytes containing different concentrations of Nd2O3 particles. The influence of Nd2O3 addition on coating growth behaviour, microstructural characteristics, and mechanical and corrosion performance was systematically investigated. Surface morphology, phase composition, hardness, and adhesion strength were analyzed, while corrosion resistance was evaluated in simulated seawater through electrochemical measurements. The results indicate that an Nd2O3 concentration of 1.5 g/L yields the most favorable coating formation conditions, characterized by enhanced growth efficiency and a compact microstructure. Under this condition, the coating exhibits a maximum hardness of 630.44 HV and an adhesion strength of 15.4 N. In addition, the corrosion current density decreases to 6.142 × 10–10 A cm–2 corrosion resistance has been significantly improved. These findings suggest that appropriate Nd2O3 incorporation during MAO effectively enhances the durability of TC4 titanium alloy in marine environments.
