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Magnesium alloys have been extensively studied as degradable biomaterials for clinical applications due to their biocompatibility and mechanical properties. However, their poor corrosion resistance can lead to issues such as osteolysis and the release of gaseous hydrogen. This study investigated the influence of the activation time of magnesium surfaces in a sodium hydroxide (NaOH) solution on the concentration of active hydroxyl groups and corrosion resistance. The results indicated that immersion time significantly influences the formation of a corrosion-resistant film and the distribution of surface hydroxyl groups. Specifically, specimens treated for 7.5 h exhibited the highest concentration of hydroxyl groups and the most uniform oxide film distribution. Electrochemical tests demonstrated capacitive behavior and passive surface formation for all evaluated times, with the 7.5-h immersion in NaOH yielding superior corrosion resistance, lower current density, and a more efficient and thicker protective film. SEM and EDS analyses confirmed increased formation of Mg(OH)2 for samples treated for 5 and 7.5 h, while a 10-h treatment resulted in a brittle, porous layer prone to degradation. Statistical analysis using ANOVA and Fisher's LSD test corroborated these findings. The optimal 7.5-h alkali treatment enhanced magnesium's corrosion resistance and surface properties, making it a promising candidate for orthopedic implants. However, further studies are necessary to assess biocompatibility and physiological responses before clinical implementation.

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Thin films of transition metal oxides and oxynitrides have proven highly effective in protecting stainless steels against corrosion in both chemically aggressive environments and biological fluids. In the present work, cerium zirconium oxynitride thin films were deposited to enhance the corrosion resistance of surgical-grade stainless steel to be used in osteosynthesis processes. Two techniques were employed: co-sputtering and radiofrequency (RF) sputtering, and the morphology and corrosion efficiency of the coatings deposited by each technique were evaluated. X-ray diffraction, X-ray photoelectron spectroscopy and field emission transmission electron microscopy were used to characterize the morphological and chemical structure, respectively. Additionally, the corrosion resistance of the oxynitride-coated surgical grade stainless steel system (ZrCeOxNy-AISI 316L) was assessed using Hank's solution as the corrosive electrolyte, to determine its resistance to corrosion in biological media. The results show that ZrCeOxNy coatings increase the corrosion resistance of surgical grade stainless steel by two orders of magnitude and that the Ce(III)/Ce(IV) equilibrium decreases the corrosion rate, thereby increasing the durability of the steel in a biological environment. The results show that Ce coatings increase the corrosion resistance of surgical grade stainless steel by two orders of magnitude and that the Ce(III)/Ce(IV) equilibrium decreases the corrosion rate, thereby increasing the durability of the steel in a biological environment.

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Sulfuric acid anodizing assisted by a hydrothermal sealing with inhibitors [Ce3+-Mo6+] was used to prevent pitting corrosion on spray-deposited hypereutectic Al-Si alloy (A390). An investigation concerning the evaluation of pitting corrosion resistance on the anodic oxide thin film with ions incorporated was carried out in NaCl solution using electrochemical measurements (i.e., potentiodynamic polarization and electrochemical impedance spectroscopy, EIS). The influence of Si phase morphology and size on the growth mechanism of an anodic oxide film was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results were then compared with those for its equivalent IM390 alloy (Al-17Si-4.5Cu-0.6Mg) produced through a conventional process ingot metallurgy, IM. The electrochemical findings indicate that sulfuric acid anodizing followed by a simple hot water sealing treatment was ineffective. In this manner, an intense attack was localized by pitting corrosion that occurred on the anodic oxide film in less than three days, as denoted by characteristic changes in the EIS spectra at the lowest frequencies. Improved results were achieved for Ce-Mo surface modification, which can provide better corrosion resistance on the aluminum alloys because no signs of pits were observed during the corrosion testing.

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The change in the corrosion activities of SS304 and the carbon steel A36 were studied during their exposure for 30 days to hybrid pumice-Portland cement extract (CE), to simulate the concrete-pore environment. The ionic composition and the initial pH (12.99) of the CE were influenced by the reduction of Portland cement (PC) content, volcanic pumice oxides and alkaline activators. Because of the air CO2 dissolution, the pH decreased and maintained a constant value ≈ 9.10 (established dynamic ionic equilibrium). The CE promoted the passivation of both steels and their free corrosion potential (OCP) reached positive values. On the surfaces, Fe and Cr oxides were formed, according to the nature of the steel. Over the time of exposure, the presence of chloride ions in the pumice caused a localized pitting attack, and for carbon steel, this fact may indicate an intermediate risk of corrosion. The chloride effect was retarded by the accumulation of SO42- ions at the steel surfaces. Based on electrochemical impedance (EIS), the polarization resistance (Rp) and the thickness of the passive layers were calculated. Their values were compared with those previously reported for the steels exposed to CEs of Portland and supersulfated cements, and the hybrid cement was considered as a PC "green" alternative.

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In the present work, the influence of a corrosive environment and temperature on the corrosion resistance properties of duplex stainless steel S31803 was evaluated. The corrosive process was carried out using solutions of 1.5% HCl (m/m) and 6% FeCl3 (m/m), at temperatures of 25 and 50 °C. The microstructure of UNS S31803 duplex stainless steel is composed of two phases, ferrite and austenite, oriented in the rolling direction, containing a ferrite percentage of 46.2% in the rolling direction and 56.1% in the normal direction. Samples, when subjected to corrosive media and temperature, tend to decrease their mechanical property values. It was observed, in both corrosive media, that with increasing test temperature, there is an increase in the corrosion rate, both uniform and pitting. The sample in HCl solution obtained a uniform corrosion rate of 0.85% at 25 °C and 0.92% at 50 °C and pitting rates of 0.77% and 1.47% at the same temperatures, respectively. When tested in FeCl3 solution, it obtained uniform corrosion of 0.0006% and 0.93% and pitting of 0.53% and 18.5%, at the same temperatures. A reduction in dissolution potentials is also noted, thus characterizing greater corrosion in the samples with increasing temperature.

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The concentration effect of Tradescantia spathacea (T. spathacea) as corrosion inhibitor of API 5L X52 steel in 0.5 M of H2SO4 was studied here through electrochemical and gravimetric techniques. To achieve it, samples of the material were prepared to be submitted to each of the tests. Results from electrochemical impedance spectroscopy (EIS) showed that there was an optimum concentration of the inhibitor in which is reached the maximum inhibition efficiency, displaying the best inhibition characteristics for this system with a maximum inhibition of 89% by using 400 ppm. However, the efficiency decreased until 40% when the temperature was increased to 60°C. Potentiodynamic polarization curves (PDP) revealed that some of the present compounds of T. spathacea may affect anodic and cathodic process, so it can be classified as a mix-type corrosion inhibitor for API 5L X52 in sulfuric acid. Also, this compound followed an adsorption mechanism; this can be described through a Frumkin isotherm with an adsorption standard free energy difference (ΔG°) of -56.59 kJmol-1. Metal surface was studied through scanning electron microscope, results revealed that by adding inhibitor, the metal surface is protected; also, they evidenced low damages compared with the surface with no inhibitor. Finally, Tradescantia spathacea inhibited the corrosion process with 82% efficiency.

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Biodiesel is a mixture of saturated and unsaturated Fatty Acid Methyl Esters (FAMEs) whose composition affects the corrosion behavior of metal containers during storage. This study examines the effect of the C=C bond present in selected FAMEs (Methyl Stearate, Methyl Oleate, and Methyl Linoleate) in aluminum corrosion in the absence of oxygen. First, mass loss assays were carried out at 100, 200, and 280 °C for 1000 h using pure Methyl Stearate (MS), 5% Methyl Oleate in Methyl Stearate (MS-5% MO), and 5% Methyl Linoleate in Methyl Stearate (MS-5% ML). Next, chemical changes in FAMEs were studied using FTIR, TGA, and GC/MS. SEM/EDS analysis allowed us to inspect the aluminum surfaces and their chemical characterization. We estimated higher corrosion rates for MS assays than those of unsaturated methyl ester mixtures. In a separate set of experiments, we used electrochemical techniques (potentiodynamic polarization, linear polarization resistance, and electrochemical impedance spectroscopy) to investigate aluminum corrosion induced by thermal-degraded products from FAMEs at 100, 200, and 280 °C for 300 h able to dissolve in aqueous extracts. These electrochemical experiments revealed that the products in the aqueous extracts from the unsaturated methyl ester mixture form a passive layer on the Al surface thicker than pure MS at the corresponding degradation temperatures.

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Corrosion processes at cut edges of galvanized steels proceed as highly localized electrochemical reactions between the exposed bulk steel matrix and the protective thin metallic coating of a more electrochemically active material. Scanning microelectrochemical techniques can thus provide the spatially resolved information needed to assess the corrosion initiation and propagation phenomena, yet most methods scan cut edge sections as embedded in insulating resin to achieve a flat surface for scanning purposes. In this work, the galvanized coatings on both sides of the material were concomitantly exposed to simulated acid rain while characterizing the cut edge response using SECM and SVET techniques, thereby maintaining the coupled effects through the exposure of the whole system as rather realistic operation conditions. The cut edges were shown to strongly promote oxygen consumption and subsequent alkalization to pH 10-11 over the iron, while diffusion phenomena eventually yielded the complete depletion of oxygen and pH neutralization of the nearby electrolyte. In addition, the cathodic activation of the exposed iron was intensified with a thinner coating despite the lower presence of sacrificial anode, and preferential sites of the attack in the corners revealed highly localized acidification below pH 4, which sustained hydrogen evolution at spots of the steel-coating interface.

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In this study was examined the response of carbon steel to atmospheric corrosion after one-year exposure in Valle de Aburrá, a subregion located in northwestern Colombia. The study involved the assessment of material mass loss and corrosion rate, the characterization of atmospheric aggressiveness, and the analysis of the morphology and composition of corrosion products in five different sites. Climatological and meteorological factors were assessed by testing for chloride content, sulfur dioxide levels, and time of wetness (TOW). The analysis of corrosion products was conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. Based on corrosion rates, two sites exhibited a more aggressive environment, with a corrosivity category of C3, while the remaining sites were categorized as C2. The study confirmed the presence of lepidocrocite and goethite phases on the surface of carbon steel at all test sites. Data analysis revealed that both the TOW and the industrial activity significantly influence the corrosion of this metal.

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Aftermarket additives are used to enhance the performance of internal combustion engines in specific aspects such as reducing wear, increasing power, and improving fuel economy. Despite their advantages, they can sometimes cause corrosion-related problems. This research evaluated the corrosiveness of four aftermarket additives on the corrosion of a high-leaded tin bronze alloy over 28 days at 80 °C in immersion tests. Among the evaluated products, three showed corrosive effects ranging from intermediate to severe. Notably, the visual appearance of the surfaces often did not indicate the underlying corrosive damage. Therefore, the assessment of corrosiveness was based on chemical characterizations conducted on both the drained oils and the bronze surfaces. The study found minimal oil degradation under the testing conditions, indicating that the primary cause of corrosion was the interaction between the specific additives and the metal elements of the alloy, rather than oil degradation itself. A direct correlation was observed between the dissolution of lead and copper and the adsorption of S and Cl-containing additives on the surfaces, respectively. The corrosive impact of Cl-containing additives in aftermarket formulations was significantly reduced when mixed with engine oil SAE 10W-30 (at a 25:1 ratio), suggesting a mitigated effect in combined formulations, which is the recommended usage for engines.

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The hexane extract of Persea schiedeana Ness (PSN) was analyzed as corrosion inhibitor for the brass surface immersed in 0.5 M HCl. Fourier-transform infrared spectroscopy and a gas chromatographic (GC) and mass spectrometric (MS) were used to identify the PSN extract's functional groups and compound constituents. The functional groups identified were CH 3 and CH 2 functional alkyl groups, C=O stretching vibration of aldehydes, ketones, and carbonyl groups. The GC/MS determined the presence of fatty acids in the PSN extract, where palmitic acid, oleic acid, and ethyl oleate were the major constituents. Electrochemical characterizations were conducted to observe the effect of PSN as corrosion inhibitor on the brass surface. The Rp and Rn calculated from EIS and ENA give the same behavior. Based on the OCP behavior, it was determined that the PSN works as a mix inhibitor, affecting both anodic and cathodic reactions. The corrosion current density (Icorr) suggests that the extract of PSN reduces the corrosion rate of the brass with efficiencies above 90% for all concentrations. The efficiency obtained for each PSN concentration was attributed to forming a corrosion scale of CuO and Cu 2 O , which reacted with the carboxyl group to form copper carboxylates on the metal surface.

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Advanced high-strength steels (AHSSs) are designed for meeting strict requirements, especially in the automotive industry, as a means to directly influence the reduction in the carbon footprint. As rotary friction welding (RFW) has many important advantages over other welding technologies, it plays an important role in the automotive sector. On the above basis, in this work, combinations of the first (complex phase (CP)), second (TWIP (TW)), and third (quenched and partitioned (Q&P)) generations of similar and dissimilar high-alloyed advanced steels have been joined by the RFW process. Having a specific microstructure, rods of CP/CP, Q&P/Q&P, CP/TW, and Q&P/TW steels were welded by employing a homemade adaptation machine under fixed parameters. Microstructural characterization has allowed us to corroborate the metallic bonding of all the tested advanced steels and to identify the different zones formed after welding. Results indicate that the welding zone widens in the center of the workpiece, and under the current friction action, the intermixing region shows the redistribution of solute elements, mostly in the dissimilarly welded steels. Furthermore, because of their complex chemistry and the different mechanical properties of the used steels, dissimilarly welded steels present the most noticeable differences in hardness. The TWIP steel has the lower hardness values, whilst the CP and Q&P steels have the higher ones. As a direct effect of the viscoplastic behavior of the steels established by the thermomechanical processing, interlayers and oxidation products were identified, as well as some typical RFW defects. The electrochemical response of the welded steels has shown that the compositional and microstructural condition mostly affect the corrosion trend. This means that the dissimilarly welded steels are more susceptible to corrosion, especially at the TWIP-steel interface, which is attributed to the energy that is stored in the distorted microstructure of each steel plate as a consequence of the thermomechanical processing during RFW.

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Objetivo: Analizar la resistencia a la corrosión por picaduras de aceros inoxidables AISI 304 y AISI 420 en un medio que contiene cloruros (solu-ción de NaCl al 0,9 y 3,5%, en masa), así como su citotoxicidad, in vitro, en muestras con y sin corrosión por picaduras. Método: Estudio experimental. Se utilizaron técnicas de polarización potenciodinámica cíclica (PPC) para caracterizar el alcance y la forma del ataque corrosivo a las muestras. Se utilizó el método de difusión en agar y evaluación de la viabilidad de la línea celular NCTC clon 929 (CCIAL 020) para evaluar la citotoxicidad de las muestras de acero con y sin picaduras. Resultados: El acero AISI 304 presentó una resistencia a la corrosión superior al acero AISI 420. Los valores de potencial de picadura disminuyeron para ambos aceros cuando aumentó la concentración de cloruros en la solución agresiva. Hubo toxicidad celular moderada (grado 3 ­ ISO 10993-5) en todas las muestras. Conclusión: Los resultados corroboraron las recomendaciones para evitar la inmersión innecesaria de instrumentos en soluciones salinas. La citotoxicidad moderada de estos aceros desaconseja su uso en dispositivos implantables, reservándolos solo para instrumentos quirúrgicos. (AU)

Objective: To analyze the pitting corrosion resistance of AISI 304 and AISI 420 stainless steels in chloride-containing medium (0.9 and 3.5% NaCl solution, by weight), as well as their cytotoxicity,in vitro, in samples with and without pitting corrosion. Method: This is an experimental study. Cyclic potentiodynamic polarization (CPP) techniques were used to characterize the extent and shape of the corrosive attack on the samples. The agar diffusion and viability evaluation method of the NCTC clone 929 cell line (CCIAL 020) was used to evaluate the cytotoxicity of samples of steels with and without pitting. Results: The AISI 304 steel showed superior corrosion resistance to the AISI 420 steel. The values of the pitting potentials decreased for both steels when the chloride concentration in the aggressive solution was increased. There was moderate cell toxicity (grade 3 ­ ISO 10993-5) in all samples. Conclusions: The results corroborated the recommendations to avoid unnecessary immersion of the instruments in saline solutions. Moderate cytotoxicity to these steels contraindicates their use in implantable devices, only in surgical instruments. (AU)

Objetivo: Analisar a resistência à corrosão por pites dos aços inoxidáveis AISI 304 e AISI 420 em meio contendo cloretos (solução de NaCl a 0,9 e 3,5%, em massa), assim como sua citotoxicidade,in vitro, em amostras com e sem corrosão por pites. Método: Estudo experimental. Utilizaram-se téc-nicas de polarização potenciodinâmica cíclica (PPC) para caracterizar extensão e forma do ataque corrosivo nas amostras. O método de difusão em ágar e avaliação da viabilidade da linhagem celular NCTC clone 929 (CCIAL 020) foi empregado para avaliar a citotoxicidade de amostras dos aços com e sem pites. Resultados: O aço AISI 304 apresentou resistência à corrosão superior ao aço AISI 420. Os valores dos potenciais de pite caíram para ambos os aços quando se aumentou a concentração de cloretos na solução agressiva. Houve moderada toxicidade celular (grau 3 ­ ISO 10993-5) em todas as amostras. Conclusão: Os resultados corroboraram as recomendações para evitar a imersão desnecessária dos instrumentais em soluções salinas. A citotoxicidade moderada para esses aços contraindica seu uso em dispositivos implantáveis, apenas em instrumentos cirúrgicos. (AU)

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Characterizing seasonal changes in diatom community profiles in coastal environments is scarce worldwide. Despite diatoms being prevalent in microfouling, their role in microbially influenced corrosion of metallic materials remains poorly understood. This study reports the effect of seasonal variations on the settlement of marine diatoms and corrosion of 316 L stainless steel surfaces exposed to Chilean coastal seawater. Electron microscopy imaging revealed a diverse assembly of diatoms, exhibiting pronounced differences at genus level between summer and winter seasons, with a significant delay in diatom settlement during winter. Electrochemical measurements indicated an active role of diatoms in increasing corrosion current during biofilm development. While the final diatom composition was similar irrespective of the season, the analyses of diatom assemblages over time differed, showing faster colonization when silicate and nitrate were available. This study lays the foundation for future research on the dominant season-specific genera of diatoms to unveil the microbial interactions that could contribute to corrosion and to evaluate their potential as bioindicators for alternative surveillance strategies.

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Microorganisms can play a significant role in material corrosion, with bacterial biofilms as major participants in microbially influenced corrosion (MIC). The exact mechanisms by which this takes place are poorly understood, resulting in a scarcity of information regarding MIC detection and prevention. In this work, a consortium of moderately thermophilic bacteria isolated from a biofilm growing over aluminum alloy 7075 was characterized. Its effect over the alloy was evaluated on a 40-day period using Electron Microscopy, demonstrating acceleration of corrosion in comparison to the abiotic control. The bacterial consortium was biochemically and microbiologically characterized as an attempt to elucidate factors contributing to corrosion. Molecular analysis revealed that the consortium consisted mainly of members of the Bacillus genus, with lower abundance of other genera such as Thermoanaerobacterium, Anoxybacillus and Paenibacillus. The EPS polysaccharide presented mainly mannose, galactose, rhamnose and ribose. Our observations suggest that the acidification of the culture media resulting from bacterial metabolism acted as the main contributor to corrosion, hinting at an unspecific mechanism. The consortium was not sulfate-reducing, but it was found to produce hydrogen, which could also be a compounding factor for corrosion.

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Abutment components (i.e., fixtures associated with oral implants) are essentially made of titanium (Ti), which is continuously exposed to the hash oral environment, resulting in scratching. Thus, such components need to be protected, and surface treatments are viable methods for overcoming long-term damage. Diamond-like carbon (DLC), an excellent protective material, is an alternative surface-treatment material for Ti abutments. Here, we demonstrate that a silicon interlayer for DLC film growth and the pulsed-direct current plasma-enhanced chemical vapor deposition (DC-PECVD) method enables the deposition of an enhanced protective DLC film. As a result, the DLC film demonstrated a smooth topography with a compact surface. Furthermore, the DLC film enhanced the mechanical (load-displacement, hardness, and elastic modulus) and tribological properties of Ti as well as increased its corrosion resistance (16-fold), which surpassed that of a bare Ti substrate. The biofilm formed (Streptococcus sanguinis) after 24 h exhibited an equal bacterial load (∼7 Log colony-forming units) for both the groups (Ti and DLC). In addition, the DLC film exhibited good cytocompatibility, owing to its noncytotoxicity toward human gingival fibroblast cells. Therefore, DLC deposition via DC-PECVD can be considered to be a promising protective and cytocompatible alternative for developing implant abutments with enhanced mechanical, tribological, and electrochemical properties.

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This study reports the use of an inorganic corrosion inhibitor to mitigate dissolved CO2-induced corrosion. Using electrochemical techniques (polarization curves, open circuit potential, polarization resistance, and electrochemical impedance), the effect of adding Nd3+ ions on the corrosion resistance of X52 steel immersed in CO2-saturated brine at 20 °C and 60 °C was evaluated. The polarization curves showed that the Icorr values tend to decrease with increasing Nd3+ ion concentration, up to the optimal inhibition concentration, and that the corrosion potential increases at nobler values. Open circuit potential measurements showed a large increase in potential values immediately after the addition of the Nd3+ ions. Similarly, polarization resistance measurements showed similar trends. It was observed that regardless of temperature, Nd3+ ions can reduce the corrosion rate by more than 97% at doses as low as 0.001 M. Electrochemical impedance measurements confirmed the formation of a protective layer on the steel surface, which caused an increase in the magnitude of the impedance module and phase angle, which indicates an increase in the resistance to charge transfer and capacitive properties of the metallic surface. The characterization of the metallic surface showed that the protective layer was formed by Nd carbonates, whose formation was due to a CO2 capture process.

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Cellular automata models have emerged as a valuable tool in corrosion management. This manuscript provides an overview of the application of cellular automata models in corrosion research, highlighting their benefits and contributions to understanding the complex nature of corrosion processes. Cellular automata models offer a computational approach to simulating corrosion behavior at the microscale, capturing the intricate interactions between electrochemical reactions, material properties, and environmental factors and generating a new vision of predictive maintenance. It reviews the key features of cellular automata, such as the grid-based representation of the material surface, the definition of state variables, and the rules governing cell-state transitions. The ability to model local interactions and emergent global behavior makes cellular automata particularly suitable for simulating corrosion processes. Finally, cellular automata models offer a powerful and versatile approach to studying corrosion processes, expanding models that can continue to enhance our understanding of corrosion and contribute to the development of effective corrosion prevention and control strategies.

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This study evaluated the behavior of three paint systems exposed to the Antarctic marine environment for 45 months compared to a control of uncoated carbon steel with a determined corrosion rate. At the study site, all environmental conditions, solar radiation, and the concentration of environmental pollutants (Cl- and SO2) were evaluated. The paint systems differed in terms of the primer and top coat. Coated samples were studied before and after exposure. They were evaluated visually and using SEM to determine adhesion, abrasion, and contact angle; using the Evans X-Cut Tape Test; using ATR-FTIR spectroscopy to analyze the state of aging of the top layer; and using electrochemical impedance spectroscopy (EIS) for coat protection characterization. The corrosion rate obtained for steel was 85.64 µm year-1, which aligned with a C5 environmental corrosivity category. In general, the evaluation in the period studied showed the paint systems had good adhesion and resistance to delamination, without the presence of surface rust, and exhibited some loss of brightness, an increase in the abrasion index, and a decrease in the percentage of reflectance due to aging. EIS showed good protection capability of the three coating schemes. In general, this type of paint system has not previously been evaluated in an extreme environment after 45 months of exposure to the environment. The results showed that the best behavior was found for the system whose top layer was acrylic-aliphatic polyurethane.

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Along with poor implant-bone integration, peri-implant diseases are the major causes of implant failure. Although such diseases are primarily triggered by biofilm accumulation, a complex inflammatory process in response to corrosive-related metallic ions/debris has also been recognized as a risk factor. In this regard, by boosting the titanium (Ti) surface with silane-based positive charges, cationic coatings have gained increasing attention due to their ability to kill pathogens and may be favorable for corrosion resistance. Nevertheless, the development of a cationic coating that combines such properties in addition to having a favorable topography for implant osseointegration is lacking. Because introducing hydroxyl (-OH) groups to Ti is essential to increase chemical bonds with silane, Ti pretreatment is of utmost importance to achieve such polarization. In this study, plasma electrolytic oxidation (PEO) was investigated as a new route to pretreat Ti with OH groups while providing favorable properties for implant application compared with traditional hydrothermal treatment (HT). To produce bactericidal and corrosion-resistant cationic coatings, after pretreatment with PEO or HT (Step 1), surface silanization was subsequently performed via immersion-based functionalization with 3-aminopropyltriethoxysilane (APTES) (Step 2). In the end, five groups were assessed: untreated Ti (Ti), HT, PEO, HT+APTES, and PEO+APTES. PEO created a porous surface with increased roughness and better mechanical and tribological properties compared with HT and Ti. The introduction of -OH groups by HT and PEO was confirmed by Fourier transform infrared spectroscopy and the increase in wettability producing superhydrophilic surfaces. After silanization, the surfaces were polarized to hydrophobic ones, and an increase in the amine functional group was observed by X-ray photoelectron spectroscopy, demonstrating a considerable amount of positive ions. Such protonation may explain the enhanced corrosion resistance and dead bacteria (Streptococcus aureus and Escherichia coli) found for PEO+APTES. All groups presented noncytotoxic properties with similar blood plasma protein adsorption capacity vs the Ti control. Our findings provide new insights into developing next-generation cationic coatings by suggesting that a tailorable porous and oxide coating produced by PEO has promise in designing enhanced cationic surfaces targeting biomedical and dental implant applications.

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