Anti-corrosion Materials Research Articles

Environmental testing of hydrophobic fluorosilane-modified substrates

Surface wettability is one of the key properties in coating science. Development of non-wettable (superhydrophobic) materials is a promising field of study, leading to many potential applications such as anti-icing, drag reduction, anti-corrosive or foul-proof materials. Different approaches to this problem led to several solutions, among which vapor phase modification seems very promising. The effects of such modification were investigated on glass and silica substrates to define changes in surface wettability. The surface was cleaned and activated by low pressure plasma and modified with fluorosilanes. Chosen modifiers were PFOTS and PFDTS. Samples were also tested in different environmental conditions in climate chamber. Obtained materials were characterized by water contact angle (WCA), surface free energy (SFE, van Oss-Good method), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. The results allowed to define surface wettability, and the impact of temperature and humidity on modified surfaces. Moreover, XPS results enabled to determine chemical composition of surface and AFM was used to analyse substrate roughness change after modification. Conducted studies allow for better understanding of surface properties modelling and also put a light on environmental durability of modified materials like nanocomposites or coatings.

Integral assessment of anti-corrosion materials‘ quality

In modern conditions, protective paint and varnish coatings are used everywhere to ensure the safety of metal structures and include the materials of various composition and application. The paints and varnishes market offers conventional hard and thixotropic anticorrosive coatings applied by the devices using airless spray technology. The article describes the experiment results, which consists in conducting a comparative analysis of protective materials in the framework of laboratory studies. The main physical and mechanical properties are determined. Modeling of anticorrosive coatings‘ indicators, which determine the degree of change in material properties in terms of adhesion, thickness, uniformity, flexibility and weather resistance of the treated surface of a metal structure, has been carried out. The values of the indicators were formed within the framework of the existing database, created and replenished using the real data obtained during the maintenance and repair of the existing facilities. The considered method is applicable for any number of analyzed surfaces and parameters of anticorrosive materials. As a result, it was found that the traditional coatings within the considered sufficiency indicators meet the specified requirements by 85-90=. However, the primer “Tectyl BT Coat” is the best option for using anticorrosive materials to protect the steel structures exposed to aggressive environmental influences. The sufficiency level for this primer is 92=, which determines its first place in the rating. The proposed method of experimental research and subsequent integral assessment of satisfying the requirements adequacy is versatile and is a tool that can be used when solving the problems of multi-criteria selection or ranking of a finite number of different anti-corrosion coatings or other objects.

MAX Phase Ceramics/Composites with Complex Shapes.

Ceramics including oxides, carbides, nitrides, borides, carbonitrides, silicates, and MAX phases have wide applications in electrode materials, high-temperature structural materials, and anticorrosive materials for harsh environments. However, the difficulty in processing ceramics with complex shapes from green powders has been restricting applications in emerging areas. Herein, polymer-derived ceramics (PDCs) were used to assist the pressureless processing of MAX phase particles. The processing temperature could be lowered by 400 to 600 °C, which is favorable for both industrialization and engineering applications. The good processability of MAX-preceramic polymer mixtures and high accuracy of replica from preceramic polymer make it possible to fabricate artificial objects with complex shapes and fine texture. This method provides a method to fabricate MAX phase ceramics/composites, as well as some other ceramics.

Environmentally favorable magnesium phosphate anti-corrosive coating on carbon steel and protective mechanisms

Polymer coatings are commonly used to protect carbon steels from corrosion but they are susceptible to weathering and many of them have environmental concerns. Therefore, we studied the possibility of an environmentally favorable inorganic magnesium phosphate cement (MPC) coating for protecting mild steel. A formulation suitable for coating steel was developed by compositional modification [i.e., incremental replacement of dead-burned magnesia (MgO) with magnesium hydroxide (Mg(OH)2)] to a road-repair MPC. This modification yielded an acceptable working time and prevented pore formation at the coating-steel interface. Corrosion monitoring by linear polarization and electrochemical impedance spectroscopy for 14 days found that, the MPC coating substantially increased the linear polarization resistance (Rp) [e.g., day 1: (8.2 ± 1.7) × 103 (nadir value) vs. 495 ± 55 Ω cm−2] and charge transfer resistance (Rct) (e.g., day 1: 9.3 × 103 vs. 3.8 × 102 Ω cm−2). The coated steel underwent neutral sodium chloride (NaCl) salt spray for 2400 h without visible rusting. Immersion for 24 h in liquids simulating the pore fluid indicated that, passivation by the excess MgO in the coating was a major contributor to its anti-corrosive property. Tafel polarization in the liquids found that, corrosion current density (Icorr) followed the rank: 3.5% NaCl solution (6.0 µA cm−2) > 3.5% NaCl solution containing MgO (3.6 µA cm−2) > 3.5% NaCl solution containing fragmented MPC (1.7 µA cm−2), suggesting that a physical barrier effect and dissolved phosphate ions improved its protection. This study shows that, MPC coating is a promising durable and environmentally favorable anti-corrosive material for protecting steel structures in some applications.

A Review of Graphene-Based Materials for Marine Corrosion Protection

Graphene-based anti-corrosion materials exhibit excellent chemical inertness and impermeability and are promising and emerging materials for the protection of metals. In this review, the recent progress in the production of graphene-based materials for protection against marine corrosion is discussed. Major mechanisms of marine corrosion and strategies for corrosion protection are illustrated. The properties and methods used for the preparation (micromechanical stripping method and chemical vapor deposition) of graphene are introduced. Two fabrication strategies for graphene-based corrosion protection materials are presented. For pure graphene films, fewer defects and low conductivity lead to the enhancement of anti-corrosion properties. For graphene composite coatings, improving the dispersibility of graphene in the coating matrix and strengthening the durability render graphene coatings to be more effective for marine corrosion protection. Insulation is highly desirable for avoiding electrochemical reactions to protect against heavy marine corrosion in the later stages. Finally, we provide perspectives on the future of graphene-based materials for marine corrosion protection, anticipating that a properly prepared graphene composite coating can serve as a long-term anti-corrosive material for marine applications.

Experimental-numerical study of residual stress in Tight Fit Pipe

For transmission of high-pressure corrosive fluids, it is required to pipe that with both anti-corrosive and high strength material. One of the economical and reliable approaches is the use of Tight Fit Pipe (TFP). Tight Fit Pipe is a double-walled pipe, where a corrosion-resistant alloy liner is fitted inside a carbon steel outer pipe through a thermal-hydraulic manufacturing process. TFP is manufactured under specified conditions for conducting this research. The most influential parameter to improve these pipes' structural response is the residual stress between the inner and outer pipes. In this study, finite element analysis and experimental method were utilized to calculate residual stress between the inner and outer pipes. A 2D finite-element model was performed in ABAQUS software to simulate the lined pipe with considering the effects of heat on the mechanical properties of the pipes and nonlinear isotropic/kinematic hardening material model. Analytical and experimental (Saw cut) methods were applied to measure residual stresses of two pipes to validate the numerical method's results. By comparing the simulation results with the experimental results, an appropriate agreement has been observed.

Research of physical and mechanical properties and development of anti-corrosion composite materials and epoxy resins and industrial waste coatings

Research of physical and mechanical properties and development of anti-corrosion composite materials and epoxy resins and industrial waste coatings

Advanced liquid epoxy and polyurethane materials: internal and external coatings for pipeline and tubing protection

The paper discusses anticorrosive materials developed by JSC “СRONOS SPb” for different application for oil/gas industry. A series of coatings were tested for compliance with industrial Russian and international standards. Epoxy KronEpur 80 and KronEpur NKT coatings for the internal surfaces of pipelines and tubing with high Tg comply with Russian state standard GOST 58346. KronTag developed for RFID tags protection meet the requirements for internal coatings according GOST 58346. Hybrid epoxy-urethane coating Eton-SAP has extremely low operational thickness. Repairing material Polykron-R tested by DIN EN 10290.

О ПРОБЛЕМАХ ЗАЩИТЫ ОТ АТМОСФЕРНОЙ КОРРОЗИИ ТЕХНИКИ И ОБОРУДОВАНИЯ В АПК

An analysis is given of some corrosion problems in the agro-industrial complex associated with various climatic conditions, specific operating environments for machinery and equipment, and some particular solutions are shown related to the use of anti-corrosion materials available and effective in agricultural production. When tested in a 3% NaCl solution for 160 days, sunflower and rapeseed oil sludges, waste motor oil purification products are effective. Protective efficiency is 89-90%. The study of soil extracts by the method of polarization curves showed that leached chernozem is more corrosive than ordinary chernozem and dark chestnut soils. Additives to soils with mineral fertilizers increase their corrosive aggressiveness, especially in the presence of moisture. The rate of corrosion in soil extracts in the presence of ammonium nitrate is 10-15% higher than in the presence of azophoska, superphosphate, and urea. Sunflower oil sludge protects the surface of 0.8 kp steel with traces of mineral fertilizers with a protective efficiency of 97-100. It has been found that at high humidity, steel is more susceptible to general corrosion than copper or brass. This trend persists at H = 100% and the simultaneous presence of CO2, H2S, NH3 in concentrations three times higher than the maximum allowable for livestock buildings. Solving the problem of the correct choice of anti-corrosion materials will reduce the losses from corrosion destruction of agricultural machinery and equipment, while observing the principle of adequacy of the cost of protection and corrosive aggressiveness of the environment.

Cationic polyurethane from CO2-polyol as an effective barrier binder for polyaniline-based metal anti-corrosion materials

An internal crosslinked waterborne cationic polyurethane from CO2-polyol featuring neutral characterization was designed and prepared for the development of a sustainable polyaniline-based metal anti-corrosion material.

Ti3C2Tx/PANI composites with tunable conductivity towards anticorrosion application

Introduction of MXene nanoflakes into organic coating is critical for enhancing mechanical properties and corrosion protection, relying on its characteristic structure and nature. But considering the high conductivity of Ti3C2Tx, it may accelerate the corrosion of steel substrate once forming an electrode, so tailoring its conductivity is of great concern. Herein, three-dimensional (3D) Ti3C2Tx/polyaniline composites (TPCs) were synthesized by oxidative polymerization of aniline monomers in Ti3C2Tx dispersion. Of great significance is to achieve the tunable conductivity from 1307 S·cm−1 (Ti3C2Tx MXene) to 0.5 S·cm−1 (TPCs) via controlling polyaniline. The correlation between the anticorrosion ability and own structure/performance of TPCs-containing coatings was assessed by multiple methods. The results demonstrate that 3D TPCs can remarkably enhance the corrosion protection, especially multilayer TPCs12-containing coating (MTPCs12, where TPCs12 denotes that the mass ratio of Ti3C2Tx MXene and aniline was 1:2) with the best anticorrosion performance. The open circuit potential (OCP) and impedance modulus of MTPCs12 can achieve a value of approximately 0.2 V vs. SCE after three hours immersion and 1.05 × 107 Ω·cm2 after 5 weeks immersion, respectively. 3D TPCs with tunable performance characteristic contribute to such an excellent corrosion protection because they can serve as a reservoir and trap caustic ions. Prospectively, TPCs show promising potentials for water splitting, desalination, electronic devices, and other desirable fields. This work not only highlights the application potential of TPCs as an effective anticorrosion material, but also broadens the application of Ti3C2Tx MXene.

Liquid-infused surfaces based on ZnO/Co3O4/SiO2 with omniphobicity and durable anti-corrosion properties

Slippery liquid-infused porous surfaces (SLIPSs) are gaining remarkable amount of interest because of their exceptional liquid and solid repellency properties, their tolerance to high pressures and transparency. The lubricant layer may be depleted, leading to the loss of the “slippery” characteristics of the SLIPSs. Herein, we aimed to increase the lubricant storage capacity to enhance the long-term stability of SLIPSs through the construction of a hierarchical structure on the alloy substrates; the SLIPS herein thus represents a new kind of anti-corrosion material. By comparing the wetting speed of the lubricant and shear resistance properties, we showed that SLIPS with a ZnO/Co3O4/SiO2 hierarchical structure provided the best lubricant wettability among the samples investigated herein; the lubricant was contained in the interior of this sample, thus providing the highest shear-tolerance observed. We also investigated the anti-corrosion property of SLIPSs that comprised ZnO/Co3O4/SiO2. The hierarchical structure had enough space to store the lubricant, which provided excellent corrosion protection for the alloy substrate.

Corrosion inhibition of layered double hydroxides for metal-based systems

Layered double hydroxide (LDH), a kind of 2D layered materials, has been recognized as the promising anticorrosion materials for metal and its alloy. The microstructure, physical/chemical properties, usage in corrosion inhibition and inhibition performance of LDH have been studied separately in open literature. However, there is a lack of a complete review to summarize the status of LDH technology and the potential R&D opportunities in the field of corrosion inhibition. In addition, the challenges for LDH in corrosion inhibition of metal-based system have not been summarized systematically. Herein, we review recent advances in the rational design of LDH for corrosion inhibition of metal-based system (i.e. Mg alloy, Al alloy, steel and concrete) and high-throughput anticorrosion materials development. By evaluating the physical/chemical properties, usage in metal-based system and the corrosion inhibition mechanism of LDH, we highlight several important factors of LDH for anticorrosion performance and common features of LDH in applying different metal alloys. Finally, we provide our perspective and recommendation in this field, including high-throughput techiniques for combinatorial compositional design and rapid synthesis of anticorrosion alloys, with the goal of accelerating the development and application of LDH in corrosion inhibition of metal-based system.

Chemical transformation of renewable algae oil to polyetheramide polyols for polyurethane coatings

Algae are a group of photosynthetic marine or freshwater plants that exhibit high CO2 capturing capacity. Algae have been among the most promising renewable resources for overcoming climate change issues. In this study, algae oil (AO) was chemically transformed to polyols through two-step reactions and incorporated into value-added and industrially important polyurethane (PU) coatings. First, AO was reacted with diethanolamine to afford fatty amide. Then, polyetheramide polyols (AEAs) were prepared by reacting the fatty amide with bisphenol-A, 1,4-butanediol, or isosorbide. PU coatings were prepared by reaction between the AEAs and diphenylmethane diisocyanate. The PUs exhibited typical semicrystalline and three-step degradation behaviors with enhanced gel content values, supporting the high reactivity of the AEAs as polyols. The hydrophobic characteristics of the fatty acid chains of the AEAs resulted in decreased water absorption of the PUs, which improved the antimicrobial characteristics of the PUs. In particular, the PU coatings exhibited excellent resistance against alkaline aqueous media and organic solvent (xylene) along with reasonable gloss, hardness, flexibility. In saline aqueous media, the PU coatings exhibited anticorrosion performance superior to that of typical poly(tetramethylene ether) glycol-based PU coating. This study demonstrates the high potential of the PUs as anticorrosion and antimicrobial materials from the environmentally friendly renewable resource.

Mapping Atmospheric Corrosivity in Shandong

Air pollution can significantly accelerate the process of material corrosion, which may cause significant economic losses and serious safety incidents. Atmospheric corrosion maps provide atmospheric corrosivity in a given geographic scope, which can guide the designers to select the most suitable anti-corrosion materials for outdoor projects, also provide useful information for maintenance. This article investigated mapping of atmospheric corrosivity in Shandong Province, China. In order to obtain atmospheric corrosivity data, 100 exposure corrosion test sites were established in Shandong according to International Standard Organization (ISO) 8565. Hot-dip galvanized steel samples were exposed for 1 year in the test sites. Taking the results of exposure corrosion test as the data, inverse distance weighting (IDW) and ordinary kriging (OK) interpolation algorithm were used to estimate the atmospheric corrosivity of Shandong Province according to ISO 9223. The validity of OK and IDW was compared in developing atmospheric corrosion maps of Shandong Province on a 1 × 1 km resolution. The cross-validation results showed that OK interpolation algorithm with Gaussian semivariogram model get the best result in the prediction of corrosion rate. When the corrosion category was used as the criterion, the IDW interpolation algorithm of power 4 performed best, predicted results of 74 sites (n = 100) were consistent with observed. However, high mean relative errors (MRE more than 37%) and relatively low correlation (R2 about 24%) indicated that the prediction results of the two interpolation algorithms had a large error, which was caused by the low data density and the complicated corrosive factors of the atmosphere.

Efficient photocathodic protection enabled by a multi-dimensional quaternary hybrid superstructure

The global annual steel waste associate with interface corrosion represent significant challenges for steel’s lifetime as well as sustainable development of modern society. Herein, we report a unique multi-dimensional quaternary hybrid superstructure for photocathodic protection (PCP) which not only has an intense visible to near-infrared absorptivity for generating ‘hot’ electrons but also can provide time-delay anti-corrosion functions in the dark. We exemplified the PCP performance of this quaternary composite on a typical 304 stainless steel (304SS) which results in its surface potential shifting negatively by about 660 mV compared to its natural corrosion potential under visible light illumination. Besides, time-delay protection without illumination is also demonstrated, which is resulted from the “electron pool” effect associates to the embedded zero-dimensional quantum dots. Based on density functional theory (DFT) simulations as well as comprehensive electron microscopy studies, we elucidate the origin of the enhanced PCP performances are attributed to the improved work per photon using ‘hot’ carriers, which surpass the limit of the state-of-the-art PCP technologies. In addition, we found the use of one-dimensional titanium dioxide nanorods and two-dimensional reduced graphene oxide as a scaffold can structure the metal nanoparticles and forces photoinduced ‘hot’ electrons to transfer to the functionalized 304SS. Various promising functionalities arises from the use of as-proposed multi-dimensional quaternary superstructure as a sustainable anti-corrosion material can be envisioned.

1-Naphthols as components for multifunctional material systems (MFMS): the molecular modeling approach

Increasing research interests have been paid to developing efficient multifunctional material systems (MFMS) by using various composite materials, owing to their useful properties and good stability. Here, we systematically studied 1-naphthols, especially how the type and position of a substituent influence the reactivity and properties, using different electron-directing groups. During computations, important preparation guidelines for thiol derivatives of 1-naphthol were obtained. It is very interesting to note that some molecules could exhibit intramolecular O–H–O interactions. Careful theoretical investigation reveals that all the tested compounds are stable and the molecules with substituents in positions 4 and 8 are the least reactive. It is also worth noting that for the stability and polarizability tensor values, it is more favorable when both substituents are in the same benzene ring. Among tested 1-naphthols, the greatest values of alpha, beta, and gamma are more than 5, 60, and 110 times better respectively, than in the urea molecule; the change of electron-withdrawing group (EWG) to electron-donating group (EDG) increases NLO effects. This study provided a new scope of 1-naphthols applicability by using them as anti-corrosion materials and as very good materials for NLO devices due to the high stability of the aromatic structure coupled with polarity given by the substituents. Also, the understanding of IR vibrations for more complex organic compounds with thiol substituent has been improved.

Peach Pomace Extract as Efficient Sustainable Inhibitor for Carbon Steel Against Chloride-Induced Corrosion

The aim of this paper is to investigate peach pomace extract as a cheap, raw, green and non-toxic anti-corrosion material for mild steel corrosion in neutral media of 0.5 M NaCl solution. The chemical profile of the extract was analyzed using gas chromatography mass spectrometry (GC–MS) and high performance liquid chromatography analysis. Gravimetric, PR technique, scanning electron microscopy were used to study the corrosion inhibitive. The influence of immersion period on inhibition efficiency was evaluated. The mechanism of action of the inhibitor is also discussed. The gravimetric, polarization measurements and surface analysis evinced that the growth of inhibitory properties is prolonged and corrosion rate reduction after 40–50 h of exposure. The potentiodynamic polarization curves indicated that PPE acts as a mixed-type inhibitor. The phenomenon of prolonged action “40–50 h” and the influence of the time of film formation on its effectiveness were explained. The formation of polymerisation flavanol-aldehyde adduct, polymers of flavan-3-ols-anthocyanins and oxidation compounds of the p-quinones structure due to extract transformation in water causes main corrosion reduction in 40–50 h.

Effect of the feeding mode of cross-linker and microcapsule on the corrosion resistance and hydrophobicity of composite coatings

The interface combination of anti-corrosive materials and polymer matrix has a significant effect on the overall performance of the composite coating. However, past research has focused on blending anti-corrosive materials to improve the performance of the polymer matrix. Herein, we proposed a layer-by-layer spray-coating process to further enhance the reinforcing effect of anti-corrosive materials on the polymer matrix by changing their feeding modes. In this paper, taking waterborne polyacrylate (WPA) as an example, two kinds of reinforcement materials commonly used to improve the corrosion resistance of polymer matrix were introduced into the coating system and then applied to the tinplate: cross-linker and microcapsule. Firstly, five types of WPA composite coating systems were designed according to the feeding mode of aziridine cross-linker and the position of benzotriazole@zinc oxide microcapsules (BTA@ZnO MCs). Electrochemical impedance spectroscopy (EIS) and electrical equivalent circuits were used to evaluate the corrosion resistance of these composite coating systems and analyze their electrochemical processes. By spraying the mixture of WPA and aziridine crosslinker as the bottom layer and BTA@ZnO MCs as the top layer, the resulting composite coating exhibited higher corrosion resistance and hydrophobic properties. Scanning electron microscope (SEM) and contact angle tests indicated that the feeding mode of aziridine cross-linker and the position of BTA@ZnO MCs played important roles in the compactness and hydrophobicity of the composite coating. Subsequently, the effects of the amount of aziridine cross-linker and BTA@ZnO MCs on the corrosion resistance and physical properties of the composite coating were further analyzed by EIS, water absorption test, contact angle test and atomic force microscopy (AFM). The significant improvement in the corrosion resistance of this composite coating was mainly attributed to the synergistic effect of highly cross-linked network structure and superhydrophobic surface.

Synthesis, Characterization and Corrosion Inhibition Performance of Glycine-Functionalized Graphene/Fe3O4 Nanocomposite (Gr/Fe@Gly NC) for Mild Steel Corrosion in 1 M HCl

We have synthesized a ternary glycine-functionalized graphene/Fe3O4 nanocomposite referred as Gr/Fe@Gly NC which was characterized by fourier transform infrared spectroscopy analysis (FT-IR), X-ray diffraction, high-resolution scanning electron microscopy/energy-dispersive X-ray spectroscopy (HR-SEM/EDS) and the transmission electron microscopy. The effectiveness of synthesized nanocomposite as anticorrosive material for mild steel in the acid medium was assessed using weight loss, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) complemented with FT-IR and SEM studies. The results of weight loss study depicted its effectiveness and stability up to 60 °C at very low concentrations. FT-IR and SEM studies supported the existence of a protective film on the inhibited steel surface. The adsorption followed the Langmuir adsorption isotherm; as such, it approximated and defined the thermodynamic and kinetic parameters governing the adsorption process. ANOVA statistical check confirmed that there is statistically no significant difference between the inhibition efficiencies obtained through weight loss, PDP and EIS techniques.