Adsorption and mitigation impact of the monosodium glutamate (C5H8NO4Na) bio-molecules on the steel rebar corrosion in the chloride-contaminated simulated concrete pore solution.

Corrosion has caused significant annual costs for building construction and civil architectural designs. In this study, Monosodium glutamate (GLU) was proposed as a potential candidate for long-lasting corrosion inhibition to slow down the rate of corrosion in the concrete pore environment. In this regard, the electrochemical and morphological properties of the various GLU concentrated systems between 1 to 5 wt% in the simulated concrete pore solution media were investigated. According to the EIS results, adding 4 wt% of GLU could reduce the mild steel corrosion process by 86% through a mixed inhibition mechanism. Also, the polarization records represented that the samples' corrosion current density was diminished to 0.169 µA cm-2 after the addition of 4 wt% GLU into the harsh environment. Using the FE-SEM method, the growth of the GLU layer over the metal substrate was demonstrated. The results of spectroscopic methods, i.e., Raman and GIXRD, demonstrated that GLU molecules were successfully adsorbed over the surface of the metal. Contact angle test outcomes showed that by increasing the GLU concentration to its optimum level (4 wt%), the surface hydrophobicity was dramatically raised to 62°.

Sustainable development of an effective anti-corrosion film over the St12-steel surface against seawater attacks using Ce(III) ions/tri-sodium phosphate anions.

One application of organic compounds is to utilize them as corrosion inhibitors in acidic environments to diminish steel corrosion. These inhibitors do not show very good inhibition properties in saline (NaCl) environments. There have been many studies on boosting these inhibitors' performance in such environments (especially Cl- containing media). One of the ways that have been proposed is the use of organic and inorganic inhibitors, simultaneously. The synergistic effect of these inhibitors has shown promising results in reducing steel corrosion. In this study, cerium(III) nitrate and tri-sodium phosphate (TSP) was used as organic and inorganic inhibitors to control the corrosion of steel in a 3.5 wt.% NaCl environment. The corrosion measurements were conducted in the 3.5 wt.% NaCl environment by EIS and polarization methods. Surface studies were done by SEM, Raman, GIXRD, and EDS methods. Corrosion studies (EIS and polarization) have revealed that when 500 ppm of Ce(NO3)3 and 500 ppm of TSP are added to the 3.5 wt.% NaCl medium, the highest synergism index (1.27) and inhibition efficiency (73.7%) are achieved. Also, by adding 500Ce-500TPS to the solution, icorr and Rct of steel decreased by about 80% and increased approximately 4-fold, respectively. This improvement in the steel performance against corrosion in the presence of an equal ratio of Ce(NO3)3 and TSP is the outcome of the formation of a hydrophobic dense film (consisting of Ce(OH)3, Ce/Fe-phosphate complexes) on the metal surface. This claim has been proven by SEM/EDS, contact angel, FT-IR, and XRD analysis.

Enhancing Self-Healing and Adhesion Bonding Properties: Investigating the Promising Potential of Ce-ZIF8 MOF Hybrid Thin Films as pH-Responsive Nanocoatings.

Further modification of the pre-treated steel surface with cerium conversion coating was performed using a novel porous coordination polymer (PCP) based on zeolitic imidazole framework-8 (ZIF8) in order to reduce the defect and disorders of the surface. The treated mild steels (MS) with Ce (MS/Ce) and Ce-ZIF8 (MS/Ce-ZIF8) were characterized by the GIXRD, Raman, and FT-IR, and via contact angle and FE-SEM, their surface features were investigated. The protection performance of the samples against corrosion was evaluated in the saline solution media using electrochemical impedance spectroscopy (EIS, in the long term) and polarization tests. The results evidenced that applying the ZIF8 nanoparticles onto the Ce-treated steel surface increased the total resistance value after 24 h of immersion (49.47%). Afterward, the ZIF8-modified coating (MS/Ce and MS/Ce-ZIF8) impact on the epoxy coating protection function was characterized by EIS (in the scratched form), salt spray (5 wt % salts), cathodic disbonding (at 25 °C), and pull-off tests. The EIS outcomes of the scratched coatings proved approximately a 51.29% increase in Rt of the MS/Ce-ZIF8/EC sample compared with the MS/EC sample after 24 h of immersion. The cathodic disbonding test results after 24 h of exposure revealed that the delamination area of the coating decreased in the modified sample, and the delamination radius of the epoxy coating was about 4.78, 2.96, and 2.0 mm for the MS/EC, MS/Ce/EC, and MS/Ce-ZIF8/EC samples, respectively.

Sulfonated Polyaniline-Grafted Two-Dimensional Ti3C2-MXene (SPANI-MXene) Nanoplatform for Designing an Advanced Smart Self-Healable Coating System.

MXene nanosheets (MXenes), a brand-new classification of two-dimensional (2D) nanomaterials, are assumed to be highly functional components in anticorrosion polymeric systems. In general, MXenes possess many advantageous features that can be utilized to improve the polymeric matrices' anticorrosion performance. In this work, zinc ions (Zn) were deposited on the sulfonated polyaniline (SPANI) that was polymerized on Ti3C2-MXene surfaces (MXP-Zn) in order to achieve a high-performance anticorrosion nanofiller for epoxy coating (EP-MXP-Zn). Field-emission scanning electron microscopy-transmission electron microscopy images, Fourier transform infrared, Raman, X-ray diffraction, UV-vis, derivative thermogravimetry, and thermogravimetric analysis have evidenced the successful characterization of the MXP-Zn nanocomposite. Likewise, the excellent barrier properties of SPANI, in conjunction with the cathodic protection of Zn, resulted in a novel nanocomposite that could mitigate the negative consequences of destructive ions' attack on the metal surface in an aggressive media. Quantitative and qualitative anticorrosion measurements verified the outstanding anticorrosion performance of EP-MXP-Zn over time in severe conditions. According to the electrochemical impedance spectroscopy assessments, the |Z0.01 Hz| value for EP-MXP-Zn was 1010.04 Ω cm2, which was over 105 times greater than that of neat EP (104.66 Ω cm2) over a 6-week period of immersion in a 3.5 wt % NaCl solution.

Design of Nacre-Inspired 2D-MoS2 Nanosheets Assembled with Mesoporous Covalent Organic Frameworks (COFs) for Smart Coatings.

High loading capacity and smart release of inhibitors are the first and foremost characteristics of nanocontainers, which play a pivotal role in metal active corrosion protection. The present work explores the development of novel protective nanocontainers based on recently emerged covalent organic frameworks (COFs). These highly porous frameworks with large surface area, outstanding thermomechanical properties, low density, and ease of functionalization are used as nanocontainers. On the other hand, molybdenum disulfide (MoS2), a state-of-the-art 2D layered compound with a sheetlike structure, was utilized thanks to its excellent barrier properties. However, these lamellar structures suffer a high agglomeration tendency in polymeric matrices. Therefore, we developed a novel hybrid nanocontainer, inspired by natural nacre, by an in situ growth of COF on MoS2 to improve the stability and provide a high inhibitor loading capacity. The porous and nitrogen-rich structure of COF made it a good carrier to adsorb europium cations as inorganic inhibitors and release them on demand by pH changes to suppress the electrochemical reactions. The as-synthesized nanoplatforms were used as pH-responsive fillers in the epoxy resin. The nanocomposite coatings showed almost 50 kΩ cm2 total resistance and high impedance values (1011 Ω cm2) even after 77 days of immersion. Moreover, salt spray analysis depicted the smallest amount of rust and corrosion product after 31 days in the filled nanocomposite coating. Cathodic delamination and pull-off outcomes denoted that the filled coatings with the as-synthesized nanofiller showed the smallest cathodic delamination radius (3.41 mm) and lowest adhesion loss (24%) compared to the neat epoxy (7.55 mm and 46.7%). As such, the highly porous modified MoS2 nanosheets are considered promising alternatives in a wide range of applications with anticorrosion properties.

Rising of MXenes: Novel 2D-functionalized nanomaterials as a new milestone in corrosion science - a critical review.

Corrosion is a natural process between a metal and its environment that can gradually cause catastrophic damage to the metal equipment, which would have economic implications. Consequently, several protective methods have been utilized to prevent metals from severe degradation. Organic polymeric coatings have been widely used as the most convenient and cost-effective method to boost metals' anti-corrosion properties. Nonetheless, these coatings have a significant amount of solvent, resulting in shrinkage and micro defects in the films during the curing process. Many studies have verified that transition metal carbides/nitrides (MXenes) can form a "labyrinth effect" in the polymeric coatings due to their "nano-barrier effect". Furthermore, based on their sheet-like structures, they can considerably cover the surface defects of the polymeric films. Therefore, the penetration of corrosive elements can be substantially curbed. It is the first review that specifically focused on the new family of 2D nanomaterials, i.e., MXenes, and discussed their applications in corrosion protection systems. The MXenes' pros and cons in the polymeric matrixes as nanofillers will be clarified. Moreover, the synthesis and functionalization methods of the MXenes, their applications, and corrosion protection mechanism will be explored. Subsequently, the MXenes' superiority over other 2D nanomaterials will be highlighted while their future perspectives and industrial applications will be predicted.

Designing Hybrid Mesoporous Pr/Tannate-Inbuilt ZIF8-Decorated MoS2 as Novel Nanoreservoirs toward Smart pH-Triggered Anti-corrosion/Robust Thermomechanical Epoxy Nanocoatings.

For the first time, organic tannic acid (TA) molecules and then inorganic praseodymium (Pr) cations as corrosion inhibitors were successfully loaded into a zeolitic imidazolate framework (ZIF8)-type porous coordination polymer (PCP) decorated on molybdenum disulfide, MoS2, (MS)-based transition metal dichalcogenides (TMDs) to create novel hybrid mesoporous Pr/TA-ZIF8@MS nanoreservoirs. Thereafter, the hybrid nanoreservoirs were embedded into the epoxy matrix for the preparation of smart pH-triggered nanocoatings. Characterizations of the Pr/TA-ZIF8@MS nanoreservoirs via Fourier transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric (TG), Brunauer-Emmett-Teller (BET), and field emission-scanning electron microscopy (FE-SEM)/energy-dispersive X-ray spectroscopy (EDS) experiments confirmed the fabrication of mesoporous structures comprising Pr/TA interfacial interactions with ZIF8-decorated MS nanoplatelets possessing high thermal stability and compact/dense configuration features with a framework reorientation. A remarkable smart release of the inhibited cations (Pr3+ and Zn2+) in the presence of inbuilt TA at both acidic and alkaline media was achieved under inductively coupled plasma (ICP) examination. The superior pH-triggered self-healing inhibition through the smart controlled-release of Pr, tannate, Zn, and imidazole inhibited species/complexes from EP/Pr-TA-ZIF8@MS via ligand exchange was obtained from electrochemical impedance spectroscopy (EIS) assessments of the scratched coatings during 72 h of saline immersion. In addition, the long-term barrier-induced corrosion prevention (log |Z|10 mHz = 10.49 Ω·cm2 after 63 days) of the EP/Pr-TA-ZIF8@MS was actualized. Moreover, efficient increments of the coating cross-link density (56.45%), tensile strength (63.6%), and toughness value (56.5%) compared to the Neat epoxy coating revealed noticeable thermomechanical properties of the EP/Pr-TA-ZIF8@MS.

Ultrastable Porous Covalent Organic Framework Assembled Carbon Nanotube as a Novel Nanocontainer for Anti-Corrosion Coatings: Experimental and Computational Studies.

Covalent organic frameworks (COFs) have been proposed as a wholly organic architecture sharing high crystallinity, porosity, and tuneability. Moreover, they exhibit highly stable structures against harsh chemical environments, including boiling water, strong acids and bases, and oxidation and reduction conditions, making them good candidates for extreme conditions. For the first time, a porous COF structure based on terephthalaldehyde and melamine was synthesized and employed as a novel nanocontainer for hosting corrosion inhibitors to provide a coating with superior active/passive anti-corrosion properties. In this study, the multi-walled carbon nanotube was utilized as a platform for growing COF (CC) to improve the coating's barrier and thermo-mechanical properties. The zinc cations were loaded into the CC structure (called CCZ) as one of the most promising inhibitors for mild steel. The COF-based nanoparticles' characterization was done by Fourier transform infrared, Raman, X-ray diffraction, thermogravimetric analysis, Brunauer-Emmett-Teller, field emission scanning electron microscopy, and transmission electron microscopy (TEM) techniques. Moreover, the Density functional theory modeling and molecular dynamics simulation quantitatively highlighted the adsorption propensity of the investigated COF structures onto the oxidized CNT-based nanostructures and the interactions of epoxy with these nanostructures. The CCZ nanoparticles (NPs) showed 75% inhibition efficiency in saline solution and 418 ppm zinc ions release after 24 h at acidic pH. The CCZ/EP coating revealed the smart release of inhibitor for 24 h and represented excellent barrier properties after 9 weeks of immersion in saline solution. In terms of mechanical properties, the elastic modulus values derived from the dynamic mechanical thermal analyzer were enhanced by 107 and 137% in CC/EP and CCZ/EP samples compared to the neat epoxy. Furthermore, the yield stress and breakpoint elongation were strengthened by 102 and 63% for the CC/EP sample, respectively. Finally, the highest pull-off adhesion strength in dry (8.53 MPa) and wet (2.7 MPa) conditions, along with the lowest adhesion loss (68.3%), was related to the CCZ/EP sample.

Stachys byzantina extract: A green biocompatible molecules source for graphene skeletons generation on the carbon steel for superior corrosion mitigation.

The presence of bio-active compounds in Stachys byzantina (SB) extract has made it a powerful source of green inhibitors in controlling steel corrosion. In this study, it has been attempted to create a highly durable corrosion protective film on the surface of the metal with SB and divalent zinc (II) cations and investigated them by Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic polarization (PP) tests, and surface analysis methods. EIS results show that after 24 h of placing the steel samples in 3.5% NaCl solution containing 700 SB - 300 ZN, the synergistic corrosion inhibition behavior was about 92%. Besides, the results of the PP demonstrated a significant reduction of the icorr. Furthermore, surface analyses such as Field Emission Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (FE-SEM/EDS) and Atomic Force Microscopy (AFM) images illustrated the low metal surface degradation, which indicates that the mix of SB and Zn caused a protective layer creation on the surface, especially for SB 700 - Zn 300. Also, new compounds of graphitic materials' structure were made using SB extract which is a natural-based chemical, and investigated by Fourier-Transform Infrared Spectroscopy (FTIR) test, Grazing Incidence X-ray Diffraction (GIXRD) technique, Ultraviolet-visible spectroscopy (UV-Vis) analysis, and Raman spectroscopy.

Benzimidazole loaded ß-cyclodextrin as a novel anti-corrosion system; coupled experimental/computational assessments.

HYPOTHESIS: Silane (sol-gel)-based coatings have been introduced as an eco-friendly system for reducing the metals' corrosion in NaCl solutions. However, due to the lack of active protection property for this type of coatings, their modification is totally recommended for achieving durable protection properties. The present study introduces Beta-cyclodextrin (ß-CD) as a novel/effective organic nano-container for Benzimidazole (BM) encapsulation to obtain reliable active protection property via a controlled-release property. EXPERIMENTS: The chemical structure of the ß-CD-BM macromolecule was explored by Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD), and Ultraviolet-visible spectroscopy (UV-Vis). Besides, the Electrochemical Impedance Spectroscopy (EIS) and polarization (potentiodynamic) tests were carried out for investigating the inhibition impacts of the constructed containers. The exposed and unexposed samples' surfaces were analyzed by Field Emission Scanning Electron Microscope (FE-SEM), Energy Dispersive Spectroscopy (EDS)/mapping, and Grazing incidence X-ray diffraction (GIXRD) experiments. Also, the EIS test was conducted over the Silane-based composite film (SCF) for analyzing the anti-corrosion performance of the constructed composites. FINDINGS: The EIS achievements demonstrated that by the addition of ß-CD-BM complexes to the saline solution, the mild steel corrosion was mitigated by about 84%. The EIS results also displayed that the total resistance of the modified composite was enhanced from 5540 Ω.cm2 to 10967 Ω.cm2 and the intact coating provided a total resistance of 80254 Ω.cm2. The dispersion-corrected Density Functional Theory (DFT)-D explorations ascertained the inclusion capacity of benzimidazole inside the ß-CD. The Monte Carlo/Molecular Dynamics (MC/MD) calculations strongly affirmed the adsorption of BM and ß-CD-BM over the substrate.

Epoxy coating anti-corrosion properties enhancement via the steel surface treatment by nanostructured samarium oxide-poly-dopamine film.

Nowadays, the rare earth element-based conversion coatings (REE-based CCs) are a potential eco-friendly alternative for hazardous and carcinogenic Cr-based CCs. These coatings have morphological defects that impair their performance; therefore, they need to be surface modified. In this study, for the first time, the steel surface was coated with an eco-friendly Sm-based CC and then post-modified by poly-dopamine based biopolymer. The air-exposed based self-polymerization and oxidant-induced polymerization are two protocols which have been utilized for poly-dopamine synthesis. The SEM/EDS analysis and Raman spectroscopy have been employed for the treated steel surface characterization. In addition, the electrochemical impedance spectroscopy (EIS) analysis and salt-spray test (SST) were carried out to investigate the epoxy (EP) coating corrosion protection performance. The Rt values of the EP applied on the Sm-PDA modified steel, subjected to a 3.5 wt. % NaCl solution, are respectively 2550 GΩ.cm2 and 100 kΩ. cm2 before and after the creation of scratch. These values are about 94000-fold and 21-fold more than the Rt of the defected/un-defected EP coatings applied on the unmodified steel. In addition, the EP applied on the Sm-PDA modified steel showed lower corrosion and less disbonding in SST and higher resistance against CD than the EP applied on the unmodified steel.

Development of a nanostructured film based on samarium (III)/polydopamine on the steel surface with superior anti-corrosion and water-repellency properties.

HYPOTHESIS: The application of various hydrophobic/superhydrophobic coatings on the surface of metals has become the hot topic of the recent studies. The corrosion protection effectiveness and environmental issues are two important factors that should be taken into consideration when developing advanced surface coatings. Recently, the rare-earth elements (i.e., samarium) and biopolymers (i.e., polydopamine) have attracted much attention in the metals' corrosion control field. EXPERIMENTS: The Sm(NO3)3 containing solution was sprayed to the steel (St-12) sheets. Then, the Sm-modified plates were post-modified by polydopamine biopolymers that were synthesized by the self-polymerization (using tris (hydroxymethyl) aminomethane as a buffer), and oxidant-induced (using CuSO4 as an oxidant) approaches. The structural analysis was carried out by different techniques such as contact angle (CA) test. Moreover, the electrochemical impedance spectroscopy (EIS) and polarization tests were performed to investigate the anti-corrosion performance of various samples. FINDINGS: The CA test results revealed that by applying the nanostructured Sm-based film, the surface of the metal becomes near superhydrophobic (CA > 140°). EIS results evidenced the significant impact of the post-treatment of the Sm-treated samples by polydopamine (PDA) nanoparticles (NPs) on its corrosion protection ability enhancement. Also, the polarization test results confirmed that all treatments could retard the corrosion of steel via a mixed-type inhibition mechanism.

Synthesis of graphene oxide nanosheets decorated by nanoporous zeolite-imidazole (ZIF-67) based metal-organic framework with controlled-release corrosion inhibitor performance: Experimental and detailed DFT-D theoretical explorations.

For the first time, the zeolite-imidazole (ZIF-67) framework, a new subfamily of metal-organic frameworks (MOFs), is synthesized on the graphene oxide (GO) platform. Co2+ (as a central atom) and 2-methylimidazole (as organic ligands) were assembled to fabricate ZIF-67/GO NPs for providing epoxy-based anti-corrosion coatings with both active (self-healing) and passive (barrier) performance. Also, the ZIF-67/GO NPs were modified by 3-Aminopropyl triethoxysilane (APS) to improve the particles compatibility with the epoxy matrix and control their solubility in saline media. The FE-SEM, FT-IR, UV-Vis, Raman, TGA, and low-angle XRD techniques were used to prove the successful ZIF-67 particles growth onto the GO platforms. Tafel (potentiodynamic) polarization test demonstrated that the ZIF-67/GO@APS NPs could protect the surface of steel through mixed anodic/cathodic type (O2 reduction/Fe oxidation) mechanisms and the corrosion current density of the iron sample decreased to 1.41 µA·cm-2. Interestingly, the epoxy coatings containing ZIF-67/GO and ZIF-67/GO@APS particles revealed long-term corrosion protection durability and outstanding self-healing anti-corrosion performance, which were well studied via EIS, salt spray, cathodic delamination, and pull-off techniques. The impedance value at the lowest frequency for the coating containing ZIF-67/GO@APS after 50 days decreased from 10.7â€¯Ω·cm2 to 10.2â€¯Ω·cm2 that showed the lowest reduction among the studied samples.

Designing a non-hazardous nano-carrier based on graphene oxide@Polyaniline-Praseodymium (III) for fabrication of the Active/Passive anti-corrosion coating.

In this work, graphene oxide (GO) based nano-platforms were applied as a non-hazardous solid container with high encapsulating capacity and controllable release activity of eco-friendly inhibitor. For the first time, the adsorption and release properties of the praseodymium cations (Pr3+) on GO nanosheets functionalized with polyaniline (PANI) were investigated. The Pr3+ cations adsorption/desorption capacity of GOPANI nano-sheets was assessed by Inductively Coupled Plasma (ICP), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FE-SEM), and High-resolution transmission electron microscopy (HR-TEM) techniques. The obtained results proved that the container modified with Pr3+ cations at pH of 7, 600 ppm of adsorpt, and 1 mg/cc of adsorbent dosage provided the highest capacity of inhibitors adsorption/release rates. The adsorption capacity of the GO-PANIs reached more than 500 mg/g. Also, the modified carrier desorbed about 70 % of loaded Pr3+ cations in the corrosion simulated condition. The self-healing anti-corrosion ability of the constructed containers in an organic-inorganic hybrid coating (OIHC) was shown by electrochemical analyses results. The resistance of coating with the loaded carriers has increased about 1 order of magnitude in comparison with the neat silane. Moreover, the scratched coatings containing the inhibitor loaded GO-PANIs showed extraordinary total resistance of about 25 Kohm. cm2.

Synthesis of a non-hazardous/smart anti-corrosion nano-carrier based on beta-cyclodextrin-zinc acetylacetonate inclusion complex decorated graphene oxide (ß-CD-ZnA-MGO).

Recently, the high research considerations have been devoted to designing smart coatings with self-healing propensity along with improved anti-corrosion properties, durability, and effectiveness. In the present work, a novel nano-container, namely beta-cyclodextrin (ß-CD), was introduced and applied for encapsulating and subsequent controlled release of a metal-organic inhibitor, namely zinc acetylacetonate (ZnA) in the polymeric matrix. The smart release is another principal object which has been lacked in recent reports. For this aim, graphene oxide nanoparticles were employed to carry the inclusion complexes (ß-CD-ZnA) to the defected zones of coatings. FT-IR, Raman, XRD, and UV-vis experiments ascertained that the ß-CD-ZnA inclusion complex successfully adsorbed onto the GO sheets modified by 3-aminopropyl tri-ethoxysilane (MGO). The electrochemical inspections (i.e., potentiodynamic polarization and EIS) proved that the ß-CD-ZnA-MGO particles could remarkably inhibit the steel corrosion in 3.5 % NaCl solution via mixed cathodic/anodic retardation mechanisms with approximately 93 % efficiency after 48 h metal exposure. It was also found that the corrosion protection performance of the polymeric matrix loaded by ß-CD-ZnA-MGO nano-particles enhanced markedly, assigning to the significant epoxy defect coverage by ß-CD-ZnA. The intelligent transmission was affirmed by EDS-mapping analysis in the defected regions of epoxy coating. The high quantity of the Zn element ensured the successful adsorption of the ZnA on the metal surface. The damage, as well as the delaminated degrees of the un-scratched epoxy coating, was estimated by the EIS experiment outcomes. Achievements reflected that the presence of ß-CD-ZnA-MGO nano-filler in the epoxy resin matrix significantly reduced the electrolyte/ion diffusion. Furthermore, the computational results elucidated from DFT-D approach clarified the stronger ß-CD-ZnA affinity towards the GO adsorbent compared with the pure ß-CD, supporting the experimental findings.

Construction of a sustainable/controlled-release nano-container of non-toxic corrosion inhibitors for the water-based siliconized film: Estimating the host-guest interactions/desorption of inclusion complexes of cerium acetylacetonate (CeA) with beta-cyclodextrin (ß-CD) via detailed electronic/atomic-scale computer modeling and experimental methods.

Utilization of the coatings with self-healing anti-corrosion activities is one of the most promising routes for the development of advanced anti-corrosion coatings. In the present work, the green/sustainable corrosion inhibitive compounds based on the cerium acetylacetonate (CeA) was loaded into a beta-cyclodextrin (ß-CD) nano-container (with negligible hazardous impacts) and through combined computer modeling and experimental approaches, the host-guest interactions/desorptions of the inclusion complexes of CeA with beta-cyclodextrin (ß-CD) were assessed. The inhibition performance of the ß-CD-CeA inclusion complex was investigated by electrochemical and surface experiments in a saline solution (NaCl, 3.5 wt.%). The particles were analyzed by Raman, XRD, FT-IR, and UV-vis spectroscopies. Additionally, the thermal properties in the 30-600 °C temperature range were examined by employing TGA/DTG test, and via the ICP analysis, the concentration of the released inorganic compounds in the electrolyte was studied. Achievements demonstrated 24 ppm Ce element existence after introducing ß-CD-CeA inclusion complexes (during 24 h) in NaCl 3.5 wt.% solution. The analysis of Tafel curves proved that the prepared ß-CD-CeA inclusion complex could inhibit the metallic substrate corrosion following the mixed cathodic and anodic mechanisms. The EIS investigation disclosed about 82 % inhibition degree after 48 h of metal immersion in the solution containing ß-CD-CeA extract. The EIS analysis clarified that the silane coating (SC) resistance was enhanced noticeably by introducing the ß-CD-CeA particles into the SC matrix. Using detailed-level (i.e., electronic and atomic) computer modeling techniques applying density functional theory (DFT), Mote Carlo (MC) and molecular dynamics (MD), the active sites, and the adsorption propensity of CeA complexes over the steel-based metallic adsorbents were explored. These modelings evidenced the CeA complexes interfacial adsorption on the steel.

Copper-enriched diamond-like carbon coatings promote regeneration at the bone-implant interface.

There have been several attempts to design innovative biomaterials as surface coatings to enhance the biological performance of biomedical implants. The objective of this study was to design multifunctional Cu/a-C:H thin coating depositing on the Ti-6Al-4V alloy (TC4) via magnetron sputtering in the presence of Ar and CH4 for applications in bone implants. Moreover, the impact of Cu amount and sp2/sp3 ratio on the interior stress, corrosion behavior, mechanical properties, and tribological performance and biocompatibility of the resulting biomaterial was discussed. X-ray photoelectron spectroscopy (XPS) revealed that the sp2/sp3 portion of the coating was enhanced for samples having higher Cu contents. The intensity of the interior stress of the Cu/a-C:H thin bio-films decreased by increase of Cu content as well as the sp2/sp3 ratio. By contrast, the values of Young's modulus, the H3/E2 ratio, and hardness exhibited no significant difference with enhancing Cu content and sp2/sp3 ratio. However, there was an optimum Cu content (36.8 wt.%) and sp2/sp3 ratio (4.7) that it is feasible to get Cu/a-C:H coating with higher hardness and tribological properties. Electrochemical impedance spectroscopy test results depicted significant improvement of Ti-6Al-4V alloy corrosion resistance by deposition of Cu/a-C:H thin coating at an optimum Ar/CH4 ratio. Furthermore, Cu/a-C:H thin coating with higher Cu contents showed better antibacterial properties and higher angiogenesis and osteogenesis activities. The coated samples inhibited the growth of bacteria as compared to the uncoated sample (p < 0.05). In addition, such coating composition can stimulate angiogenesis, osteogenesis and control host response, thereby increasing the success rate of implants. Moreover, Cu/a-C:H thin films encouraged development of blood vessels on the surface of titanium alloy when the density of grown blood vessels was increased with enhancing the Cu amount of the films. It is speculated that such coating can be a promising candidate for enhancing the osseointegration features.

A green assisted route for the fabrication of a high-efficiency self-healing anti-corrosion coating through graphene oxide nanoplatform reduction by Tamarindus indiaca extract.

The major focus of the recent studies in metals corrosion protection field is now the development of non-hazardous and eco-friendly materials as effective substitutes for some of the well-known conventional toxic/unsafe inhibitors based on chromate, lead, phosphate, and azole derivatives. The present work focuses on the sustainable development of an intelligent self-healing anticorrosion coating using nanocarriers based on the graphene oxide nanoplatform-Tamarindus indiaca extract-Zn2+ (GON-Ti.E-Zn)-through a facile green assisted route. The GON-Ti.E-Zn nanocarrier was introduced into the epoxy ester film (EEF) to achieve a smart barrier/self-healing anti-corrosive property. To this end, a couple of characterization tests, including FT-IR, UV-vis, XRD, TGA, and Raman spectroscopy, have been carried out to investigate the GON-Ti.E-Zn nanocarrier structure/composition. The effectiveness of the anti-corrosion performance of the established coatings was confirmed by EIS, FE-SEM, and accelerated salt spray (SS) test. The observation of the high impedance magnitude at low-frequency (47.14 Gohm cm2 after 5 weeks immersion in saline solution) for the un-defected EEF and significant impedance enhancement for the defected EEF including GON-Ti.E-Zn nanocarrier confirmed the excellent barrier effect of GO and synergistic behavior and noticeable corrosion inhibition impact of Tamarindus indiaca along with the zinc cations on the mild steel corrosion mitigation.

L-cysteine reduced/functionalized graphene oxide application as a smart/control release nanocarrier of sustainable cerium ions for epoxy coating anti-corrosion properties improvement.

One of the main limitations for large scale mass production of reduced graphene oxide is the application of some toxic and hazardous reducing agents such as hydrazine and borohydride. In this study, the effectiveness of the l-Cys (HSCH2CH(NH2)CO2H) molecules, as a green amino acid in the GO reduction, as well as its active corrosion inhibition capacity were explored. The l-Cys/GO nanosheets were then modified by trivalent-cerium ions to obtain a nanocarrier with excellent controlled release activity. The electrochemical impedance spectroscopy (EIS) and polarization tests were used to measure the smart corrosion inhibition activity of the cerium modified l-Cys/GO nanocarrier in the saline solution and epoxy coating. The results showed that the cerium ions adsorption on the l-Cys/GO nanosheets obeyed a Langmuir isotherm model. The l-Cys/GO sample showed cerium ions adsorption capacity about 66% higher than the unmodified GO nanosheets. Furthermore, the EIS tests results revealed that in the presence of cerium modified l-Cys/GO nanocarriers the improvement in the corrosion resistance of bare steel in the solution phase and coated sample was about 7.5 times (after 24 h) and 950 times (after 40 days) higher than the blank saline solution and the pure epoxy sample, respectively.

Synthesis and characterization of a high-quality nanocontainer based on benzimidazole-zinc phosphate (ZP-BIM) tailored graphene oxides; a facile approach to fabricating a smart self-healing anti-corrosion system.

This paper describes the synthesis of a novel corrosion inhibitor nanocarrier based on benzimidazole-zinc phosphate (ZP-BIM) tailored graphene oxide (GO) and its application in the epoxy-based composite coating for the achievement of smart self-healing anti-corrosion properties toward mild steel (MS) against saline solution. The morphology and chemical/phase composition of the GO-ZP-BIM particles were investigated by FE-SEM/EDS, FT-IR, Raman spectroscopy, XPS and XRD methods. The amounts of the released inhibitive ions (i.e. PO43- anions/Zn2+ cations) and BIM molecules from the GO-ZP-BIM particles in the NaCl solution were determined by ICP analysis and UV-Visible method. The electrochemical test results in the solution phase revealed the high inhibition activities for GO-ZP (68.2%) and GO-ZP-BIM (86.5%) composites. The results of the FE-SEM/EDS analyses proved that a compact inhibitive film composed of the zinc and BIM containing compounds generated on the steel surface when subjected to the saline solution containing the GO-ZP-BIM extract. The EIS and salt spray test results demonstrated excellent barrier/active inhibition performance of the epoxy film loaded with 0.15 wt% GO-ZP-BIM particles. The combined barrier effect of the GO sheets and the inhibition activity of ZP-BIM resulted in the superior self-healing anti-corrosion properties for the epoxy film.