Corrosion Protection Applications Research Articles

Experimental and computational analysis of poly(4-vinyl pyridine) and polyvinylpyrrolidone as effective corrosion inhibitors for low carbon steel in sulfuric acid

This study investigates the inhibitory effects of poly(4-vinyl pyridine) (P4VP) and polyvinylpyrrolidone (PVP) on the corrosion of low carbon steel (LCSt) in 1 M H2SO4. Protection efficacy (%PE) was measured using mass loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Results showed %PE values increased with higher polymer concentration and lower temperature. At 450 mg/L, %PE reached 93.13% and 94.19% for P4VP and PVP, respectively. These polymers function as mixed inhibitors, adsorbing onto the LCSt surface per Langmuir’s model as a mode of physical adsorption. EIS indicated that higher polymer concentration increased charge transfer resistance and decreased effective double-layer capacitance. Both P4VP and PVP also reduced pitting corrosion in chloride-containing solutions. Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) optimized the molecular structures of the inhibitors, evaluating electronic parameters such as frontier molecular orbital (FMO) energies, energy gap, softness, hardness, electron transfer fraction, dipole moment, and hyperpolarizability ( β ° ). Monte Carlo (MC) and molecular dynamics (MD) simulations provided insights into adsorption mechanisms, corroborating experimental findings and highlighting the effect of protonation. This comprehensive study enhances our understanding of the relationship between molecular structure and function in polymer inhibitors, improving their application in corrosion protection.

Chitosan and Its Derivatives as a Barrier Anti-Corrosive Coating of 304 Stainless Steel against Corrosion in 3.5% Sodium Chloride Solution

This study investigates the corrosion resistance of chitosan and its crosslinked form coatings applied on stainless steel as substrate using various analytical techniques. Fourier transform infrared spectroscopy (FTIR-ATR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were employed for surface characterization. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques were used to analyze the electrochemical behavior. Four coatings were evaluated along with naked stainless steel (ss): chitosan (Chi), chitosan crosslinked with ammonium paratungstate (Chi/PTA), chitosan crosslinked with polyethylene glycol (Chi/PEG), and chitosan crosslinked with polyvinylpyrrolidone (Chi/PVP). Electrochemical measurement parameters analysis assessed the coating corrosion resistance, such as impedance modulus (|Z|) and corrosion potential (Ecorr). Results indicate varying degrees of corrosion resistance among the coatings. Chi/PTA exhibited notable characteristics in the electrochemical tests, showing promising polarization resistance (Rp) and impedance behavior trends. Conversely, Chi/PEG showed differing electrochemical responses, suggesting higher susceptibility to corrosion under the study conditions. These findings contribute to understanding the electrochemical performance of chitosan-based coatings on stainless steel, highlighting their potential in corrosion protection applications.

Anti-corrosion superhydrophobic micro-GF/micro-TiB2/nano-SiO2 based coating with braid strengthening structure fabricated by a single-step spray deposition

Superhydrophobic surfaces with self-cleaning, anti-biofouling and corrosion resistance merits are attractive for applications in major engineering fields. Generally, these surfaces possess low-surface-energy chemistry and micro- or nanoscale surface roughness. However, rough surfaces are fragile and highly susceptible to abrasion for high local pressures under mechanical load, causing loss of superhydrophobicity. In this study, we proposed a "fiber weaving/hard particles embedding-soft membrane" strategy to construct a kind of organic-inorganic composite coating by embedding micro-glass fiber (GF)/micro-TiB2/nano-SiO2 particles into the polydimethylsiloxane (PDMS)@polyurethane (PU) for fabricating robust superhydrophobic coating. The addition of micro-nano ceramic particles plays two roles including "hard" micro-skeletons to overcome vulnerable issue of "soft" organic membrane and creation of wear-resistant bearing points on the surface. Furthermore, "soft" membrane can absorb stress when subjected to external mechanical force and PU serves as an adhesive to improve interfacial bond strength. Additionally, GF intersperses in the coating, providing anchoring effect and PDMS serves as a modifier to decrease surface energy. Consequently, the proposed hybrid coating could simultaneously augment its mechanical robustness and multifunctional performance, breaking the notorious "trade-off" restriction of superhydrophobic coating. The preparation parameters and operation condition on the performance of the coating were investigated systematacially. The optimized superhydrophobic coating exhibits the highest water contact angle (WCA) of 167.3° ± 3.9°, the lowest sliding angle (SA) of 4.6° ± 1.3°, corrosion protection efficiency of 95.7 % in 3.5 wt% NaCl solution, with exceptional self-cleaning, anti-pollution, adaptability to various substrates, thermostable, anti-icing and mechanical stability properties, among the top-tier multifunctional performance. The inherent properties of micro-glass fiber, micro-TiB2 and nano-SiO2 ceramics and their highly ordered arrangement in the superhydrophobic coating are expected to provide an effective and versatile design proposal for potential applications in corrosion protection.

Current Status of Image Recognition Technology in the Field of Corrosion Protection Applications

Current Status of Image Recognition Technology in the Field of Corrosion Protection Applications

NIR-Driven Self-Healing Phase-Change Solid Slippery Surface with Stability and Promising Antifouling and Anticorrosion Properties.

Slippery liquid-infused porous surfaces (SLIPSs) have great potential to replace traditional antifouling coatings due to their efficient, green, and broad-spectrum antifouling performance. However, the lubricant dissipation problem of SLIPS severely restricts its further development and application, and the robust SLIPS continues to be extremely challenging. Here, a composite phase-change lubricant layer consisting of paraffin, silicone oil, and MXene is designed to readily construct a stable and NIR-responsive self-healing phase-change solid slippery surface (PCSSS). Collective results showed that PCSSS could rapidly achieve phase-change transformation and complete self-healing under NIR irradiation and keep stable after high-speed water flushing, centrifugation, and ultrasonic treatment. The antifouling performance of PCSSS evaluated by protein, bacteria, and algae antiadhesion tests demonstrated the adhesion inhibition rate was as high as 99.99%. Moreover, the EIS and potentiodynamic polarization experiments indicated that PCSSS had stable and exceptional corrosion resistance (|Z|0.01Hz = 3.87 × 108 Ω·cm2) and could effectively inhibit microbiologically influenced corrosion. The 90 day actual marine test reveals that PCSSS has remarkable antifouling performance. Therefore, PCSSS presents a novel, facile, and effective strategy to construct a slippery surface with the prospect of facilitating its application in marine antifouling and corrosion protection.

Structure-property relationship and emerging applications of nano- and micro-sized fillers reinforced sialon composites: a review

Oxonitridoaluminosilicates (SiAlON) are renowned in advanced ceramics for their exceptional properties: high temperature stability, excellent oxidation resistance, and good wear resistance. Incorporating micro- and nano-sized fillers into SiAlON matrices enhances their properties, yielding SiAlON composite materials with superior mechanical, tribological, and thermal characteristics. This review examines fabrication techniques for producing SiAlON micro/nanocomposites and the structure-property relationships governing their performance across different phase compositions (β, α, X, and O-phases). A comprehensive literature review scrutinized fabrication techniques and structure-property relationships from various databases and scholarly articles. Although SiAlON composites with micro/nano inclusions hold promise across applications, understanding their fabrication processes, structure-property relationships, and potential applications in different fields is crucial. The review highlights diverse fabrication techniques for SiAlON micro/nanocomposites and provides insights into their structure-property relationships. Additionally, emerging applications in structural domains, cutting tools, coatings, corrosion protection, solar cells, LEDs, biomedical realms, and filtration membranes are discussed. This review is a valuable resource for researchers and engineers interested in designing SiAlON products tailored for sophisticated applications. It emphasizes understanding fabrication processes and structure-property relationships to unlock SiAlON-based materials' full potential across industries.

Organic-inorganic hybrid epoxy resin coating with high thermal stability and hydrophobicity for corrosion protection prepared by (3-aminopropyl) triethoxysilane as a bridging agent

The corrosion protection application of epoxy resin (EP) in high-temperature environments is greatly restricted due to thermal stability limit and inherent hydrophilicity. In this study, a hybrid epoxy resin was synthesized by grafting hexadecyltrimethoxysilane (HDTMS), 1 H,1 H,2 H,2 H-perfluorodecyltrimethoxysilane (PFDTMS), and tetraethyl orthosilicate (TEOS) onto the molecule of epoxy resin, using (3-aminopropyl) triethoxysilane (APTES) as a bridging agent. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses revealed the presence of C-N bonds and Si-O-Si bonds in the hybrid epoxy resin, confirming the success of the hybridization. Compared to pure epoxy resin, the hybrid epoxy resin coating effectively enhances the thermal stability while maintaining both corrosion resistance and hydrophobicity. Thermal gravimetric analysis (TGA) indicated that the initial decomposition temperature (T5%) of the hybrid epoxy resin coating increased from 327°C to 372°C. This enhancement is attributed to the introduction of Si-O-Si bonds and an increase in cross-linking density in the hybrid epoxy resin. Water contact angle measurements showed that with the introduction of C-F bonds and long carbon chains, the contact angle increased from 71° to 106°. The hydrophobic hybrid epoxy resin coating maintained a contact angle of 100° at 300°C for 300 hours. The transition from hydrophilicity to hydrophobicity improves the corrosion resistance of the coating.

High‐potent trifunctional polybenzoxazines coatings for superhydrophobic cotton fabrics and mild steel corrosion protection applications

AbstractNew trifunctional polybenzoxazines were developed and utilized as a high‐potent coating material for superhydrophobic cotton fabrics and mild steel corrosion protection applications. New trifunctional benzoxazines resin have been synthesized using trihydroxytriphenylmethane (TTM) with dimethylaminopropylamine (dmapa), 1‐(3‐aminopropyl)imidazole (ipa) and aminoethoxyethanol (aee) as amine sources with paraformaldehyde through Mannich condensation. The structural confirmation of synthesized benzoxazines was ascertained by spectral studies. The ring opening polymerization of TTM‐Bzs was studied using DSC analysis. All the three TTM‐Bz monomers show curing temperature lower than 210°C. The thermo‐stability and water contact angle (WCA) of polybenzoxazines were studied using thermogravimetric analysis and goniometer, respectively. Among the TTM‐PBz studied, the poly(dmapa) exhibit better thermo‐stability and hydrophobic behavior when compared to rest of the synthesized polybenzoxazines. Poly(TTM‐dmapa)‐coated cotton fabric exhibits the superhydrophobic behavior and mild steel (MS)‐coated specimen possesses the higher charge transfer resistance value of 3.47 × 107 Ω cm2. It was also inferred that all the TTM‐PBz‐coated MS specimens exhibit higher corrosion protection behavior as well as good thermo‐stability and hydrophobic nature. Further, the obtained results suggested that these materials can be suitably exploited for hydrophobic anticorrosion applications with improved performance and enhanced longevity.

Synergistic effect of α-alumina integrated silica ceramic nanocomposites prepared using waste beverage cans and rice husk for corrosion protection application

In this study, we investigated the synergistic effect of α-alumina-integrated silica nanocomposites as a promising material for corrosion protection. We synthesized these nanocomposites in different proportions (90 wt% silica:10 wt% alumina (AS-1) and 70 wt% silica:30 wt% alumina (AS-2)) via ball milling using rice husk and waste beverage cans as the precursor source. XRD, FTIR and EDX analysis of α-Al2O3 integrated silica nanocomposites revealed distinct peaks corresponding to both silica and α-Al2O3 components, confirming the successful formation of the nanocomposites. FESEM and TEM analyses showed that the α-alumina and silica nanoparticles were agglomerated and inhomogeneous, with sizes ranging from 150 nm to 250 nm. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests showed that pure silica, AS-1, and AS-2 had corrosion rates of 1.7648, 0.4396, and 0.0610 mm/yr, respectively. AS-1 and AS-2 exhibited higher charge transfer resistance (Rct) values of 34.54 KΩ and 48.60 KΩ, respectively, compared to pure silica (24.4 KΩ). Nyquist and Bode plots revealed the improved corrosion resistance of α-alumina-integrated silica nanocomposites compared to pristine silica-based protective coatings on mild steel. It is noted that the amount of α-alumina content enhances the corrosion resistance efficiency of the nanocomposites. The synergistic effect of the α-alumina-integrated silica nanocomposites can be attributed to the improved barrier properties and forming a protective layer on the metal substrate, effectively mitigating the corrosion process.

Sustainable Surface Engineering Techniques: Evaluating the Environmental Footprint of Laser and Electron Beam Methods

This study provides an extensive overview of the latest developments in metal surface engineering, including methodologies, characterizations, and applications. The study highlights how important surface engineering is for improving metallic materials’ functionality and performance across a range of sectors. Therefore, a series of techniques are presented in this paper for evaluating design surfaces’ mechanical properties, topological properties, and microstructure. This paper presents a review of current advances in the field, focusing on functionalized surfaces for energy applications, nanostructured coatings for corrosion protection, and biomedical applications of modified surfaces. Since lasers and electron beams are mechanically and tribologically superior, there is a long discussion about their environmental footprint. A special focus in the study is on surface functionalization, nanostructured coatings, corrosion protection, and biological applications, as well as recent developments in the field. The paper also discusses the impact they have on the environment. Surface engineering approaches have long been known to enhance corrosion protection, wear resistance, and component functionality in aerospace, automotive, electronics, and healthcare sectors. Thus, the paper’s conclusion emphasizes that more research and development are needed to overcome constraints and take advantage of emerging trends in surface engineering in order to overcome constraints and take advantage of new trends. The paper provides a solid foundation for future research and development in a range of industries affected by surface engineering.

Construction of eco-friendly multifunctional cashew nut shell oil-based waterborne polyurethane network with UV resistance, corrosion resistance, mechanical strength, and transparency

Vegetable oil-based waterborne polyurethane possesses numerous advantages, including its sustainability, environmental friendliness, and economic benefits. Nevertheless, its application is constrained by inferior mechanical properties and a low glass transition temperature. Hereon, the renewable polyols of sorbitan monooleate/cytidine were incorporated into the anionic cashew nut shell oil-based WPU network through molecular structure design. Series of CNSL-based WPU with outstanding UV resistance, mechanical properties, corrosion resistance, and transparency were successfully synthesized. The effects of Ce/SP content on the performance of CNSL-based WPU dispersions and films were investigated. The results demonstrated a remarkable enhancement in the properties of the modified WPU films. Specifically, the tensile strength and Tg were increased from 9.7 MPa to 23.9 MPa and 1.1 °C to 45.8 °C, respectively, while maintaining a toughness of 26 MJ/m−3, which attained or even surpassed the current vegetable oil-based WPU systems. It was confirmed excellent UV resistance within the UVB and UVC spectrums. Furthermore, with the increase in Ce/SP content, the water contact angle of films increased slightly, enhancing its water resistance. The IE of WPU-Ce and WPU-SP films reached 97.93 % and 98.42 % respectively, indicating outstanding corrosion resistance. This work presented novel strategies for the advancement of high-performance bio-based WPU, which held promising potential in diverse areas including coatings, corrosion protection, inks, and wearable applications.

Microscale Corrosion Inhibition Behavior of Four Corrosion Inhibitors (BTA, MBI, MBT, and MBO) on Archeological Silver Artifacts Based on Scanning Electrochemical Cell Microscopy.

The problem of corrosion-induced discoloration and embrittlement in silverware is a significant concern for the long-term preservation of excavated archeological silver artifacts, even after thermal restoration. The key to addressing this issue lies in the meticulous selection and evaluation of corrosion inhibitors that possess targeted corrosion inhibition capabilities. This study focuses on the evaluation of corrosion inhibitors for archeological silver artifacts using scanning electrochemical cell microscopy (SECCM) and X-ray photoelectron spectroscopy (XPS). The researchers aimed to compare the inhibition effects of four corrosion inhibitors [1,2,3-benzotriazole (BTA), 2-mercaptobenzimidazole (MBI), 2-mercaptobenzothiazole (MBT), and 2-mercaptobenzoxazole (MBO)] on a simulated Ag-Cu alloy sample and understand their mechanisms. The results showed that MBT exhibited better corrosion inhibition for microstructural regions with higher silver content due to its ability to form stable chelation structures with Ag(I). MBO exhibited better corrosion inhibition for microstructural regions with higher copper content due to its strong affinity with Cu(I). The targeted corrosion inhibition ability for the β-phase was ranked as MBO > BTA ≈ MBI > MBT, while for the α-phase the ranking was MBT > MBO > MBI > BTA. The study demonstrated the feasibility and capabilities of SECCM in the targeted screening of corrosion inhibitors for different compositions and microstructural regions in archeological metal artifacts. This study highlights the potential of SECCM in corrosion inhibitor research for archeological metal artifacts and wider applications in metal material corrosion protection.

Chlorine resistance of tannic acid anticorrosive coating on galvanized steel in simulated concrete pore solution

Reinforced concrete structures are easily damaged by corrosion in a chloride environment. Although zinc coating provides a promising method for inhibiting steel corrosion, it can inevitably dissolve and fail under a chlorine-containing concrete environment. In this study, the chloride corrosion resistance of coatings prepared with different concentrations of tannic acid was studied in a simulated concrete pore solution. The surface morphology and chemical composition of the different samples were investigated. The results of the corrosion immersion and electrochemical tests showed that the prepared corrosion resistance coating effectively enhanced the chlorine corrosion resistance of steel. The 10 wt% tannic acid coating on the galvanized steel surface had good corrosion resistance. The corrosion resistance efficiency increased 77.8%. The green and environmentally friendly method is expected to provide an essential application in chloride corrosion protection of concrete structures.

Role of different metal precursors based MOFs for boosting anti-corrosion performance of mild steel in acid media

Benefiting from their significant features such as large specific surface area, adjustable structure and function, regular pore arrangement, and abundant active sites, metal organic frameworks (MOFs) exhibit great application prospects as anti-corrosion materials. Herein, (M-BTC, M = Mn, Fe, and Co, and BTC = benzenetricarboxylate) was prepared under solvothermal conditions and used as a highly efficient inhibitor for the protection of mild steel. The microstructure and physicochemical properties of the compounds were determined by powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR), N2-adsorption, and microscopic analysis. The addition of MOF-based corrosion inhibitors decreases the rate of mild steel surface corrosion in acidic media due to the formation of an adsorbed layer on the metal surface. The inhibition mechanisms obey the Langmuir adsorption isotherm. A Mn-MOF based corrosion inhibitor recorded an inhibition efficiency of 94.7% at 200 ppm. At the end, the future outlooks of prepared MOFs for corrosion protection are provided. We hope this work will illuminate the achievement of high-performing anticorrosion MOFs and offer new ideas for the development of MOF-based materials for future corrosion protection applications.

Fabrication and characterization of graphene oxide-based polymer nanocomposite coatings, improved stability and hydrophobicity

In this study, acrylic-epoxy-based nanocomposite coatings loaded with different concentrations (0.5–3 wt.%) of graphene oxide (GO) nanoparticles were successfully prepared via the solution intercalation approach. The thermogravimetric analysis (TGA) revealed that the inclusion of GO nanoparticles into the polymer matrix increased the thermal stability of the coatings. The degree of transparency evaluated by the ultraviolet–visible (UV–Vis) spectroscopy showed that the lowest loading rate of GO (0.5 wt.%) had completely blocked the incoming irradiation, thus resulting in zero percent transmittance. Furthermore, the water contact angle (WCA) measurements revealed that the incorporation of GO nanoparticles and PDMS into the polymer matrix had remarkably enhanced the surface hydrophobicity, exhibiting the highest WCA of 87.55º. In addition, the cross-hatch test (CHT) showed that all the hybrid coatings exhibited excellent surface adhesion behaviour, receiving 4B and 5B ratings respectively. Moreover, the field emission scanning electron microscopy (FESEM) micrographs confirmed that the presence of the functional groups on the GO surface facilitated the chemical functionalization process, which led to excellent dispersibility. The GO composition up to 2 wt.% showed excellent dispersion and uniform distribution of the GO nanoparticles within the polymer matrix. Therefore, the unique features of graphene and its derivatives have emerged as a new class of nanofillers/inhibitors for corrosion protection applications.

Coating of Carbon Nanotubes Using Chemical Method to Enhance the Corrosion Protection of Copper and Aluminum Metals in Seawater Medium

In this study, carbon nanotubes were prepared using a pure chemical method modified similar to the Hummers method with simple changes in the work steps. The carbon nanotubes were then coated and reduced on copper and aluminum metals using the electrodeposition method (EDP) for corrosion protection application in seawater medium (NaCl 3.5%) at four different temperatures: 20, 30, 40, and 50 °C, which were studied using three electrode potentiostats. All corrosion measurements, thermodynamics, and kinetics parameters were nominated from Tafel plots. The films deposited by the carbon nanotubes were examined by the SEM technique, and this technique showed the formation of carbon nanotubes.

8‐Hydroxyquinoline‐functionalized chitosan Schiff base as an efficient and environmentally friendly corrosion inhibitor for N80 steel in acidic environments

AbstractChitosan is an environmentally friendly biomolecule with great potential for application in metal corrosion protection. First, Chitosan benzaldehyde schiff base (CTSB) and 8‐hydroxyquinoline functionalized chitosan benzaldehyde schiff base (HQ‐CTSB) were synthesized from chitosan, benzaldehyde, and 8‐hydroxyquinoline as high‐efficiency and environment‐friendly corrosion inhibitors. The structures of the synthesized products were characterized by infrared spectroscopy. The corrosion of N80 steel was tested using electrochemical measurements and analysis by varied concentrations of CTSB and HQ‐CTSB in a hydrochloric acid solution. The PDP results confirmed that both CTSB and HQ‐CTSB corrosion inhibitors were mixed corrosion inhibitors. Furthermore, the EIS findings revealed that the corrosion inhibition efficiency of the two inhibitors was 87.11% and 98.52% at 800 mg/L, respectively. According to SEM and XPS analyses, the CTSB and HQ‐CTSB molecules bonded to the surface of N80 steel and formed a surface protective layer. Density functional theory (DFT) calculations showed that CTSB and HQ‐CTSB have multiple active sites that may become adsorbent on the metal surface. And molecular dynamics (MD) simulations showed that corrosion inhibitors CTSB and HQ‐CTSB lie flat on the surface of Fe(110). The theoretical calculation agreed well with the experimental results.

SiO2 nanoparticles-containing slippery-liquid infused porous surface for corrosion and wear resistance of AZ31 Mg alloy

A slippery liquid-infused porous surface (SLIPS) was developed, based on MgAl-layered double hydroxide (LDH), in order to improve the corrosion and wear resistance of AZ31 Mg alloys. In particular, different concentrations of SiO2 nanoparticles were incorporated into the silicone oil to further ameliorate the performances of Mg alloys, which can effectively seal the nanopores constructed by MgAl-LDH. With increasing SiO2 nanoparticle concentration, the nanosheet microstructure of MgAl-LDH was gradually covered by the hierarchical structure of SiO2 nanoparticles. The formed composite SiO2-SLIPSs exhibited good surface hydrophobicity and superior corrosion and wear resistance. When the concentration of SiO2 nanoparticle was 10 mg mL−1, the composite SLIPS showed the best performances, with the lowest corrosion current density of 2.43 × 10-10 A cm−2 and wear volume of 0.041 mm3. The developed composite SLIPSs could find wide applications in effective corrosion and wear protection of Mg alloys in industry.

Comparison of the Electrochemical Response of Carbon-Fiber-Reinforced Plastic (CFRP), Glassy Carbon, and Highly Ordered Pyrolytic Graphite (HOPG) in Near-Neutral Aqueous Chloride Media

Carbon-fiber-reinforced polymers (CFRP), being conductive, are capable of supporting cathodic oxygen reduction reactions (ORR) and thus promote galvanic corrosion when coupled to many metallic materials. Hence, understanding cathodic processes at carbon surfaces is critical to developing new strategies for the corrosion protection of multi-material assemblies. In the present work, the electrochemical responses of CFRP, glassy carbon, and HOPG (Highly Ordered Pyrolytic Graphite) have been evaluated in a quiescent 50 mM NaCl solution, and their respective activities towards ORR have been ranked. Employing the averages of the specific charges (CFRP, 129.52 mC cm−2; glassy carbon, 89.95 mC cm−2; HOPG, 60.77 mC cm−2) passed during 1 h polarization of each of the 3 carbon surfaces at −1000 mVSCE in the test media as a ranking criterion, the propensities of the 3 carbon surfaces (CFRP, GC, and HOPG) to support cathodic activities that can lead to anodic metal dissolution on galvanic coupling to metallic materials are ranked thusly; CFRP > GC > HOPG. This ranking is consistent with the trend of capacitance values obtained in this work: CFRP (19.5 to 34.5 μF cm−2), glassy carbon (13.6 to 85.5 μF cm−2), and HOPG (1.4 to 1.8 μF cm−2). A comparison of electrochemical data at potentials relevant to galvanic coupling to metals indicated that at these cathodic potential(s) the CFRP surface is the most electrochemically active of the studied carbon surfaces. On the basis of the values and trends of the electrochemical parameters evaluated, it is postulated that the observed differences in the electrochemical responses of these 3 carbon-rich surfaces to ORR are significantly due to differences in the proportions of edge sites present on each carbon surface. These results could provide valuable insights on plausible strategies for designing carbon surfaces and carbon fiber composites with reduced activity toward ORR for corrosion protection applications or enhanced activity towards ORR for energy applications.

Layered double hydroxides for corrosion-related applications-Main developments from 20years of research at CICECO.

This work describes the main advances carried out in the field of corrosion protection using layered double hydroxides (LDH), both as additive/pigment-based systems in organic coatings and as conversion films/pre-treatments. In the context of the research topic "Celebrating 20years of CICECO", the main works reported herein are based on SECOP's group (CICECO) main advances over the years. More specifically, this review describes structure and properties of LDH, delving into the corrosion field with description of pioneering works, use of LDH as additives to organic coatings, conversion layers, application in reinforced concrete and corrosion detection, and environmental impact of these materials. Moreover, the use of computational tools for the design of LDH materials and understanding of ion-exchange reactions is also presented. The review ends with a critical analysis of the field and future perspectives on the use of LDH for corrosion protection. From the work carried out LDH seem very tenable, versatile, and advantageous for corrosion protection applications, although several obstacles will have to be overcome before their use become commonplace.