Anticorrosion properties of nanocomposites coatings: A critical review

Impact of Co3O4 nanoparticles on epoxy's mechanical and corrosion-resistance properties for carbon steel in seawater

Co3O4 nanoparticles (Co3O4-NPs) are synthesized using the facile solvothermal method. FT-IR and XRD spectroscopic analyses verify the creation of cobalt oxide nanoparticles with an average size of 13.20 nm. Furthermore, Zeta potential assessments were carried out to identify the electrical charge of the surface of the produced Co3O4-NPs, which was found to be -20.5 mV.  In addition, the average pore size of Co3O4-NPs is 19.8 nm, and their BET surface area is 92.4 m/g. The study also concerned the effect of Co3O4-NPs on epoxy's improvement of mechanical and corrosion protection for carbon steel in salt solution. By including Co3O4-NPs in an epoxy (EP) coating, corrosion is effectively prevented by non-permeable protective coatings that effectively reduce the transfer of corrosion ions and oxygen.

Influence of Dilution on the Mechanical Properties and Microstructure of Polyurethane-Cement Based Composite Surface Coating

Polyurethane-cement composite are widely used in modern civil engineering, and the method of adding diluent is often used to adjust the construction process to adapt to the engineering environment. Studies have shown that the addition of diluent impacts the performance of polyurethane-cement based composite surface coatings, but there have been few reports on the influence of diluent content on the mechanical properties and microstructure of the coatings. To address this, polyurethane coatings with different diluent contents were prepared, and positron annihilation lifetime spectroscopy was used to test the microstructure of the coatings. The tensile strength and elongation at rupture were tested using a universal material testing machine, and the fracture interface morphology of each coating was observed by scanning electron microscopy. Finally, the correlation between the microstructure parameters and the mechanical properties of the coating was analyzed using grey relation theory. The results demonstrated that with the increase in diluent content, (i) the average radius of the free volume hole (R) and the free volume fraction (FV) of the coating both showed a trend of first decreasing and then increasing. The value of R was between 3.04 and 3.24 Å, and the value of FV was between 2.08 and 2.84%. (ii) The tensile strength of the coating increased first and then decreased, while the elongation at rupture decreased first and then increased. Among them, the value of tensile strength was between 3.23 and 4.02 MPa, and the value of elongation at fracture was between 49.34 and 63.04%. In addition, the free volume in polymers plays a crucial role in facilitating the migration of molecular chain segments and is closely related to the macroscopic mechanical properties of polymers. A correlation analysis showed that the R value of the coating had the greatest influence on its tensile strength, while FV showed a higher correlation with the elongation at rupture.

Synthesis, description, and application of novel corrosion inhibitors for CS AISI1095 in 1.0 M HCl based on benzoquinoline derivatives

This study aims to synthesize and evaluate the corrosion inhibition properties of three newly prepared organic compounds based on benzo[h]quinoline hydrazone derivatives. The compounds structure were characterised using FTIR, 1H-NMR, 13C-NMR and Mass spectroscopy. Electrochemical methods, including Potentiodynamic Polarization (PP), Electrochemical Frequency Modulation (EFM), and Electrochemical Impedance Spectroscopy (EIS) were employed to evaluate the compounds as corrosion inhibitors in HCl (1.0 M) for carbon steel (CS). Additionally, surface examination techniques such as scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to investigate the surface morphology and elemental composition of the CS before and after exposure to the synthesized compounds. The electrochemical measurements showed that compound VII achieved corrosion inhibition efficiency. SEM and EDX analysis further confirmed the creation of a passive film on the CS surface. These findings demonstrated the potential of benzo[h]quinoline hydrazone derivatives as effective organic corrosion inhibitors for CS in aggressive solution.

Insight into the Mechanisms of Nitride Films with Excellent Hardness and Lubricating Performance: A Review

Transition metal nitride (TMN) films with excellent hardness and lubricating performance are versatile low dimension materials, which are widely used in various fields including industries, transportation, aerospace, and so on. This paper introduces one film design strategy and provides a review of the mechanisms for strengthening and lubricating nitride films. The design strategy refers to two aspects which determine the structures, the performance, the components, and the chemical constitutions of nitride films The strengthening mechanisms of nitride films are then illuminated in detail, including the solid solution effect, the grain size effect, the secondary phase effect, the stress or stress field effect, the template effect, and the valence electron concentration effect. Five lubricating mechanisms are next summarized, including the easy-shear nature, the tribo-chemical reactions, the lubricious fluorides, the textured contact surface, and the synergistic effect. This paper aims to give a comprehensive introduction for understanding the mechanisms of strengthening and lubrication of nitride films for students and researchers, as well as to understand the current research progress in nitride films for exploring research gaps.

Nanocomposite Coatings for Anti-Corrosion Properties of Metallic Substrates

Nanocomposites are high-performance materials with exceptional characteristics that possess properties that their individual constituents, by themselves, cannot provide. They have useful applications in many fields, ranging from membrane processes to fuel cells, biomedical devices, and anti-corrosion protection. Well-tailored nanocomposites are promising materials for anti-corrosion coatings on metals and alloys, exhibiting simple barrier protection or even smart auto-responsive and self-healing functionalities. Nanocomposite coatings can be prepared by using a large variety of matrices and reinforcement materials, often acting in synergy. In this context, recent advances in the preparation and characterization of corrosion-resistant nanocomposite coatings based on metallic, polymeric, and ceramic matrices, as well as the incorporation of various reinforcement materials, are reviewed. The review presents the most important materials used as matrices for nanocomposites (metals, polymers, and ceramics), the most popular fillers (nanoparticles, nanotubes, nanowires, nanorods, nanoplatelets, nanosheets, nanofilms, or nanocapsules), and their combinations. Some of the most important characteristics and applications of nanocomposite coatings, as well as the challenges for future research, are briefly discussed.

Novel Corrosion Inhibitor for Carbon Steel in Acidic Solutions Based on α-Aminophosphonate (Chemical, Electrochemical, and Quantum Studies)

α-aminophosphonate (α-AP) is used as a novel corrosion inhibitor for carbon steel. The aggressive media applied in this study are HCl and H₂SO₄ acid solutions. The findings indicate that the morphology of the α-AP compound is cubic, with particles ranging in size from 17 to 23 μm. FT-IR, ¹HNMR, ³¹PNMR, and ¹³CNMR analysis confirmed the synthesis of the α-AP molecule. It has been discovered that the compound α-AP plays an important role in inhibiting the corrosion of carbon steel in both HCl and H₂SO₄ acids. This was identifiably inferred from the fact that the addition of α-AP compound decreased the corrosion rate. It is important to report that the maximum inhibition efficiency (92.4% for HCl and 95.7% for H₂SO₄) was obtained at 180 ppm. The primary factor affecting the rate at which steel specimens corrode in acidic electrolytes is the tendency of α-AP compounds to adsorb on the surface of steel through their heteroatoms (O, N, and P). This was verified by SEM/EDX results. The adsorption actually occurs through physical and chemical mechanisms via different active centers which are matched with the calculated quantum parameters. In addition, the adsorption of α-AP follows the Langmuir isotherm.

Electrochemical and theoretical investigations of favipiravir drug performance as ecologically benign corrosion inhibitor for aluminum alloy in acid solution

Aluminum-silicon alloys have become a preferred option in the automotive and aerospace industries thanks to their fault-tolerant process ability and reasonable static characteristics at relatively affordable costs. This study aimed to investigate the use of favipiravir (FAV) drug as a biocompatible and eco-friendly inhibitor to protect aluminum alloy (AlSi) surface in an aggressive acid environment (1.0 M HCl). The electrochemical measurements declare that FAV is categorized as an inhibitor of mixed type with a cathodic effect. At 100 ppm, FAV had the highest inhibitory efficiency (96.45%). FAV is associated with lower double-layer capacitance values and more excellent charge-transfer resistance. These results show that AlSi corrosion in 1.0 M HCl is reduced in the presence of FAV. The Langmuir model is well-suited to the FAV adsorption behavior (R² ≈ 1). Chemisorption is the primary adsorption in this environment. The theoretical calculation studies corrosion inhibitors' molecular structure and behavior. Different quantum chemical properties of the FAV have been calculated, including energy difference (ΔE), softness, global hardness, and energy of back-donation depending on the highest occupied and lowest unoccupied molecular orbitals. In addition, Mulliken and Fukui's population analysis and the Molecular Electrostatic Potential map represent the electron distribution and the molecule's active centers. Experimental findings and quantum chemical computations matched, and FAV is recommended as a green corrosion inhibitor.

Corrosion inhibition of mild steel in hydrochloric acid solution by the expired Ampicillin drug

This study examines the utilization of the expired drug, namely ampicillin, as a mild steel corrosion inhibitor in an acidic environment. The inhibitor was evaluated using weight loss and electrochemical measurement accompanied with surface analytical techniques. The drug showed a potential inhibitory efficiency of > 95% at 55 °C. The inclusion of the inhibitor increased the charge transfer resistance at the steel-solution interface, according to impedance analyses. According to potentiodynamic polarisation measurements, expired ampicillin drug significantly decreased the corrosion current density and worked as a mixed-type corrosion inhibitor. The Langmuir adsorption isotherm was followed by the adsorption of ampicillin drug on the steel substrate, exhibiting an association of physical and chemical adsorption mechanisms. The surface study performed using contact angle and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) measurements supported the inhibitor adsorption on the steel substrate.

New imidazolium-based ionic liquids for mitigating carbon steel corrosion in acidic condition

Two environmentally friendly inhibitors of imidazolium-based ionic liquids namely 3-benzyl-1-hexadecyl-1H-imidazol-3-ium chloride (IL-H), and 3-(4-chlorobenzyl)-1-hexadecyl-1H-imidazol-3-ium chloride (IL-Cl) were manufactured and their chemical structures were confirmed by spectra tools (FT-IR, and 1H NMR). The utilizing of these two new ionic liquids as green corrosion inhibitors for low carbon steel (LCS) in 1.0 M HCl under altered experimental conditions. Mass loss (ML), potentiodynamic polarization (PP), AC impedance spectroscopy (EIS) and surface morphology are take place in this study. The protection performance found to increase with increasing ionic liquid dose and temperature, reaching 92.9% and 95.1% for IL-H and IL-Cl at 120 ppm, respectively. Based on the PP records, the investigated ionic liquids behave as mixed-type inhibitors, influencing both anodic and cathodic responses. The inhibitory activity from these explored ionic liquids was stimulated by their adsorption on the effective surfaces of the steel surface in accordance with the Langmuir adsorption isotherm. The Density Functional Theory (DFT) method is used to analyze the relationship between quantum chemical calculations and the protection efficiency of ionic liquids.

Anticorrosion performance assessment of silane-modified chitosan/epoxy primer coatings on mild steel in saline environment using computational simulation techniques

The anticorrosion performance of silane-modified chitosan/epoxy primer coatings was evaluated using quantum chemical computations (QCC) and molecular dynamics simulation (MDS) techniques. The objective was to appraise the molecular/atomistic level performance of silane-modified chitosan/epoxy primer coating system on mild steel in saline water to be able to design robust anticorrosion epoxy nanocomposite primer coating for marine application. The QCC showed that quantum parameters for (3-aminopropyl) trimethoxy silane-modified chitosan nanocluster (AMCN) are optimum and therefore correspond to high corrosion protective capability. The adsorption energies (E_ads) for AMCN/epoxy, tetraethoxysilane-modified chitosan/epoxy, chitosan-modified epoxy, and unmodified epoxy coatings were found to be - 3094.65, - 2,630.00, - 2,305.77, and - 1,189.33 kcal/mol, respectively. The high negative value of E_ads indicates the coating molecules interacted and adsorbed strongly on the mild steel surface. Hence, AMCN/epoxy coating is potentially most corrosion-resistant than the others. Further, it is established that shorter bond length corresponds to higher bond strength and therefore indicates chemical interaction. Thus, the radial distribution function showed the bond lengths between atoms of the AMCN and mild steel surfaces were shorter than those of other molecules. Overall, AMCN/epoxy coating molecules possess good anticorrosion properties and therefore would perform well if deployed for service in saline environments.

Strategies for CO2 capture: positive and negative feature

Carbon dioxide is one of the primary greenhouse gases affecting climate change and global warming. Thus, capturing carbon dioxide (CO2) has always been a significant issue in the environmental industry. Numerous procedures have been used to remove acid and natural gas from the flue. This review aims to illustrate and discuss the primary CO2 capture technologies, such as adsorption, absorption, and membrane separation. Moreover, the development of every technology.

The most popular and effective synthesis processes for Co3O4 nanoparticles and their benefit in preventing corrosion

Cobalt oxide nanostructures are gaining popularity in the scientific community because they are reasonably priced, easy to develop, and have unique properties that make them valuable for coating, corrosion inhibitors, supercapacitors, photocatalysis, and other applications. In this review, the most well-known and effective synthetic methods are mentioned along with their particle size. A description of the main experimental methods used to describe the nanoparticles is also provided. In addition, the green production of cobalt oxide nanoparticles using plant extract is summarized. In particular with regard, we mentioned the use of cobalt oxide nanoparticles in the construction of nanocomposites coatings and future prospective approaches.

Mesoporous silica nanoparticles as carriers of active agents for smart anticorrosive organic coatings: a critical review

Mesoporous silica nanoparticles (MSN) have attracted increasing interest for their applicability as smart nanocarriers of corrosion inhibitors, due to their porous structure, resistance to main corrosive environments and good compatibility with polymer coatings. In this review, the main synthetic routes to obtain MSN with tailored textural properties, the design of different loading and stimuli-induced release strategies, the development of advanced organic nanocomposite coatings with MSN and the validation of their anticorrosive performances are reviewed and compared. Through a critical analysis of the literature, the most promising research trends and perspectives to exploit the highly interesting properties of MSN in advanced organic coatings are proposed.

Cold-Cured Bisphenolic Epoxy Adhesive Filled with Low Amounts of CaCO3: Effect of the Filler on the Durability to Aqueous Environments

The effects of aging exposures to three non-saline aqueous environments on the compressive mechanical properties of a calcium carbonate-filled bisphenolic epoxy adhesive, cold-cured with the addition of two curing agents suitable for the cure at ambient temperature (i.e., Mannich base and triethylenetetramine), were assessed. The amount of the added filler (CaCO₃) varied from 1 to 3 g per 100 g of resin; the immersion times in each of the selected medium varied from 1 to 10 months. It was found that the mechanical properties measured in compression mode on cylindrical specimens of unfilled and CaCO₃-loaded epoxy were scarcely influenced by the kind of curing agent employed; only the compressive modulus was limitedly affected by this parameter. Referring to the behavior when aged in water, the CaCO₃-filled epoxies displayed noticeable growths in modulus, small reductions in strength, and limited variations in strain, with a certain influence of the exposure time, especially when comparing the properties at the lowest time with those at medium–long times. On the basis of the results of statistical MANOVA analysis, it can be concluded that among the compositional factors (i.e., the type of curing agent employed to cure the epoxy compounds and the micro-filler content), only the amount of CaCO₃ filler significantly affects the compressive modulus.

DFT, Monte Carlo and molecular dynamics simulations for the prediction of corrosion inhibition efficiency of novel pyrazolylnucleosides on Cu(111) surface in acidic media

Five novel pyrazolylnucleosides have been evaluated theoretically for their corrosion inhibition efficiency on the Cu(111) surface in acidic media. DFT calculations were carried out to exhibit the intrinsic properties such as lowest unoccupied (ELUMO) and highest occupied (EHOMO) molecular orbital energies, as well as energy gap (∆E), chemical hardness (η), chemical softness (σ), electronegativity (χ), electrophilicity (ω) and nucleophilicity (ε). The theoretical FT-IR spectra were recorded to indicate the presence of the specific bonds in the studied molecules. The surface interactions between the inhibitor molecules and the metal surface were investigated using molecular dynamics simulations and Monte Carlo (MC) simulations. As a result, we have found that the inhibitor pyrazolylnucleosides 5a-e have strong interactions with Cu(111) surface, and therefore have excellent predictive inhibition power against copper corrosion.

Recent Advances and Trends of Nanofilled/Nanostructured Epoxies

This paper aims at reviewing the works published in the last five years (2016–2020) on polymer nanocomposites based on epoxy resins. The different nanofillers successfully added to epoxies to enhance some of their characteristics, in relation to the nature and the feature of each nanofiller, are illustrated. The organic–inorganic hybrid nanostructured epoxies are also introduced and their strong potential in many applications has been highlighted. The different methods and routes employed for the production of nanofilled/nanostructured epoxies are described. A discussion of the main properties and final performance, which comprise durability, of epoxy nanocomposites, depending on chemical nature, shape, and size of nanoparticles and on their distribution, is presented. It is also shown why an efficient uniform dispersion of the nanofillers in the epoxy matrix, along with strong interfacial interactions with the polymeric network, will guarantee the success of the application for which the nanocomposite is proposed. The mechanisms yielding to the improved properties in comparison to the neat polymer are illustrated. The most important applications in which these new materials can better exploit their uniqueness are finally presented, also evidencing the aspects that limit a wider diffusion.