Analyze the Performance of Electroactive Anticorrosion Coating of Medical Magnesium Alloy Using Deep Learning

Electroactive anticorrosion coatings are specialized surface treatments that prevent or minimize corrosion. Thestudy employs strategic thermodynamic equilibriumcalculations to pioneer a novel factor in corrosion protection.A first-time proposal, the total acidity (TA) potential of the hydrogen (pH) concept significantly shapes medicalmagnesium alloys. These coatings are meticulously designed for robust corrosion resistance, blending theoreticalinsights and practical applications to enhance our grasp of corrosion prevention mechanisms and establisha systematic approach to coating design. The groundbreaking significance of this study lies in its innovativeintegration of the TA/pH concept,which encompasses the TA/pH ratio of the chemical environment. This approachsurpasses convention by acknowledging the intricate interplay between the acidity and pH levels within thecoating formulation, thereby optimizing metal-phosphate-based conversion coatings and transforming corrosionmitigation strategies. To authenticate the TA/pH concept, the study comprehensively compares its findings withexisting research, rigorously validating the theoretical framework and reinforcing the correlates among TA/pHvalues and observed corrosion resistance in the coatings. The influence of mutations that occur naturally inthe detergent solution on persistent phosphorus changes is shown by empirical confirmation, which improvescorrosion resistance. This realization advances the field ofmaterials and the field’s knowledge of coated generation,particularly anticorrosion converter layers.

Developing single-atom catalyst-based epoxy coating with active nanocatalytic anticorrosion performance in oxygen environment

The stimuli-responsive anticorrosion coatings have drawn great attention as a prospective corrosion protection approach due to their smart self-repairing properties.In contrast to passive protection mechanism based on post-corrosion microenvironmental changes,a unique active protection strategy based on nanocatalytic oxygen depletion is proposed in this work to inhibit the occurrence of corrosion.Porous FeeNeC catalysts with outstanding oxygen reduction reaction(ORR)activity(half-wave potential of 0.89 V)is firstly synthesized through pre-coordination with organosilane precursor to obtain homogeneously distributed active sites.When this catalyst is introduced into the coating matrix,uniformly distributed FeeNeC not only compensates the defects but plays a crucial role in adsorption and consumption of diffused oxygen in the coating.Under this dual action,the penetration of corrosive medium,especially oxygen,through coating to metal substrate is greatly suppressed,resulting in effective corrosion inhibition and a significant increase in corrosion resistance of the composite coating compared to pure epoxy coating.This work provides a new perspective and the starting point for the design of high-performance smart coating with active anticorrosion properties.

Improvement of anticorrosion and adhesion to magnesium alloy by phosphate coating formed at room temperature

A new surface protection process was developed to magnesium alloy against corrosion in aggressive environments.Firstly,a phosphate coating was formed on rinsed magnesium alloy.Then,powder painting was carried out on the phosphated magnesium alloy.Surface morphologies and phase compositions of the phosphate coating were investigated by X-ray diffraction(XRD) and scanning electron microscope(SEM) .The results show that the phosphate coatings formed in bath containing earth additives at room temperature have dense and fine microstructure.The phosphate coating provides excellent paint adhesion to the magnesium alloy. Salt spray tests indicate that the corrosion resistance of the phosphate coating plus paint could meet the demand of magnesium alloy automobile components in aggressive environments.

Developing polydopamine modified molybdenum disulfide/epoxy resin powder coatings with enhanced anticorrosion performance and wear resistance on magnesium lithium alloys

Epoxy resin powder coating has been successfully applied on the corrosion protection of magnesium lithium alloys.However,poor wear resistance and microcracks formed during the solidification have limited it extensive application.There are limited approaches to exploit such anti-corrosion and mechanical properties of magnesium lithium alloys.Herein,the epoxy resin powder coating with polydopamine modified molybdenum disulfide(MoS_(2)@PDA-EP powder coating with 0,0.1,0.2,0.5,1.0 wt.%loading)was well prepared by melt extrusion to investigate its anticorrosion performance and wear resistance.The results revealed that the addition of MoS_(2)@PDA enhanced the adhesion strength between coatings and alloys,wear resistance and corrosion protection of the powder coatings.Among them,the optimum was obtained by 0.2 wt.%MoS_(2)@PDA-EP powder coating which could be attributed to well dispersion and efficient adhesion with coating matrix.To conclude,MoS_(2)@PDA-EP powder coating is meaningfully beneficial for the anticorrosive and wear performance improvement of magnesium lithium alloys.

Fabrication of superhydrophobic reduced-graphene oxide/nickel coating with mechanical durability,self-cleaning and anticorrosion performance

There is a great challenge to fabricate superhydrophobic coating with excellent mechanical durability and corrosion resistance.Inspired by the pinecone-shaped structure,a novel reduced-graphene oxide(rGO)/Ni composite coating with pinecone-like micro/nanostructures was fabricated successfully on a stainless steel substrate using a simple electrodeposition method combining Ni pre-deposition and an elevated current assistant approach.The results show that the coating is of self-cleaning and superhydrophicity with a water contact angle(CA)of 162.7°±0.8°and a sliding angle(SA)of 2.5°±1.0°.Importantly,the coating still maintains the excellent self-cleaning and superhydrophicity,water CA of 155.8°±1.2°and SA of 5.9°±1.2°,even after 100-cycle mechanical abrasion.Meanwhile,the coating also exhibits good anticorrosion performance in 3.5 wt%NaCl solution,with 99.98%inhibition efficiency.The simple fabrication method may provide a cost-effective way to prepare mechanically durable,anticorrosive,self-cleaning and superhydrophobic coatings on metal substrates.

A New Type Anticorrosion Coating for Ocean Reinforced Concrete Structures

Corrosion of reinforced concrete structures is a serious problem in ocean engineering. As an orientation of study, anticorrosion coating technique is developed and widely applied, but many problems need to be solved. LSW-2 type anticorrosion coating for maritime reinforced concrete structures is characterized by sea water resistance, salt fog resistance, moisture and heal resistance as well as impermeability to chlorions. The new type coating can be applied to wet concrete surface by conventional construction technique. It is a breakthrough in solving the above mentioned problem. The paper mainly introduces the test results, the property indices, coating procedure, construction technique and economic benefit of Ihe coating.

Smart anticorrosion coating based on stimuli-responsive micro/nanocontainer:a review

Smart coating for corrosion protection of metal materials(steel,magnesium,aluminum and their alloys)has drawn great attention because of their capacity to prevent crack propagation in the protective coating by releasing functional molecules(healing agents or corrosion inhibitors)on demand from delivery vehicle,that is,micro/nanocontainer made up of a shell and core material or a coating layer,in a controllable manner.Herein,we summarize the recent achievements during the last 10 years in the field of the micro/nanocontainer with different types of stimuli-responsive properties,i.e.,pH,electrochemical potential,redox,aggressive corrosive ions,heat,light,magnetic field,and mechanical impact,for smart anticorrosion coating.The state-of-the-art design and fabrication of micro/nanocontainer are emphasized with detailed examples.

Competitive Adsorption of Anticorrosion and Antiwear Additives

Simulated adsorptive experiments using the axletree and lubricating oil containing anticorrosion additive were conducted,and the UV absorbance of the lubricating oil before and after the adsorptive experiments was measured.Through the UV spectral measurements the difference in UV absorbance of the lubricating oil before and after the adsorptive experiments was identified,the adsorbed quantity of anticorrosion additive in the interfacial film between lubricating oil and bearing was calculated using the Lambert-Bell principle to verify the adsorption of corrosion inhibitor on the surface of friction pairs.Adsorption experiments on lubricating oil containing both antiwear and anticorrosion additives were carried out and the UV absorbance of lubricating oil samples before and after the experiments was measured to determine the difference in the UV absorbance among lubricating oil samples with the same mass fraction of anticorrosion additive and different mass fractions of antiwear additive.By measuring the ultraviolet spectral absorbance of lubricating oil samples and calculating the adsorbed quantity of anticorrosion additive in the interfacial film it was possible to determine the influence of antiwear additive on the quantity of adsorbed anticorrosion additive on the surface of friction pairs and verify the competitive adsorption relationship between the antiwear additive and the anticorrosion additive.

Anticorrosion performance of the coating/metal system by electrochemical impedance spectra

In order to investigate the anticorrosion performance of the organic coating/metal system, electrochemical impedance spectra （EIS） were measured in the 3.5wt% NaCl solution, the chemical component and the formation of corrosion products scale were analyzed by laser Raman microspectroscopy, and the pattern of the organic coating/metal system was observed by scanning electron microscopy （SEM）. The characteristics and the delamination process of the organic coating/metal system were investigated systematically, and the emphases were on the transportation of the corrosive medium and the changes of the coating/metal interface. The results show that the impedance decreases at the initial immersion, then increases at the middle-immersion, and again decreases at last, which is related to the corrosion products scale. The concentration of Cl in the coating, which destroys the corrosion products scale, increases with the immersion time.

Anticorrosion of WO₃-Modified TiO₂Thin Film Prepared by Peroxo Sol-Gel Method

The aim of this study was to develop a method to prepare WO3-TiO2 film which has high anticorrosion property when it was coated on type 304 stainless steel. A series of WO3-modified TiO2 sols were synthesized by peroxo-sol gel method using TiCl4 and Na2WO4 as the starting materials. TiCl4 was converted to Ti(OH)4 gel. H2O2 and Na2WO4 were added in Ti(OH)4 solution and heated at 95°C. The WO3-TiO2 sol was transparent, in neutral (pH^7) solution, stable suspension without surfactant, nano-crystallite and no annealing is needed after coating, and very stable for 2 years in stock. WO3-TiO2 sol was formed with anatase crystalline structure. These sols were characterized by XRD, TEM, and XPS. The sol was used to coat on stainless steel 304 by dip-coating. The WO3-TiO2 was anatase in structure as characterized by X-ray diffraction. There were no WO3 XRD peaks in the WO3-TiO2 sols, indicating that WO3 particles were very small, possibly incorporating into TiO2 structure, providing the amount of WO3 was very small. The TiO2 particles were rhombus shape. WO3-TiO2 had smaller size area than pure TiO2. The SEM results showed that the film coated on the glass substrate was very uniform. All films were nonporous and dense films. Its hardness reached 2 H after drying at 100°C, and reached 5 H after annealing at 400°C. The WO3-TiO2 film coated on 304 stainless steel had better anticorrosion capability than the unmodified TiO2 film under UV light illumination. The optimum weight ratio of TiO2: WO3 was 100:4.

Charge storage coating based triboelectric nanogenerator and its applications in self-powered anticorrosion and antifouling

As a novel energy-harvesting device,a triboelectric nanogenerator(TENG)can harvest almost all mechanical energy and transform it into electrical energy,but its output is low.Although the micro-nano structures of triboelectrode surfaces can improve their output efficiency,they lead to high costs and are not suitable for large-scale applications.To address this problem,we developed a novel TENG coating with charge-storage properties.In this study,we modified an acrylic resin,a friction material,with nano-BaTiO_(3) particles and gas phase fluorination.The charge-trapping ability of nanoparticles was used to improve the output of TENG.The short-circuit current and the output voltage of coating-based TENGs featuring charge storage and electrification reached 15μA and 800 V,respectively,without decay for longtime working.On this basis,self-powered anticorrosion and antifouling systems are designed to reduce the open circuit potential of A3 steel by 510 mV and reduce the adhesion rate of algae on the surface of metal materials.This study presents a high-output,stable,coating-based TENG with potential in practical applications for anticorrosion and antifouling.

New branched benign compounds including double antibiotic scaffolds:synthesis,simulation and adsorption for anticorrosion effect on mild steel

In this study,two novel environmental benign double antibiotic norfloxacin or ciprofloxacin scaffolds included branched molecules were prepared by multi-step routes and purified by simple performance,which were used as the target compounds(TCs).Meanwhile,a single norfloxacin or ciprofloxacin skeleton based molecules were synthesized as the reference compounds(RCs).The molecular geometry optimization and material simulation computation revealed that TCs presented smaller HOMOLUMO energy gaps and larger binding energy levels on mild steel surface than RCs.The chemical adsorption of TCs on steel surface was confirmed by X-ray photoelectron spectroscopy,which could be processed by TCs chelation with iron ions.It was shown that TCs could be self-adsorbed on steel surface,which was demonstrated by atomic force microscopy and scanning electron microscopy.The anticorrosion of the studied compounds for mild steel in HCl solution was investigated by electrochemistry analysis.The results suggested that the anticorrosion efficiency could reach 95.86%(TC1)and 97.05%(TC2)at 0.050 mmol·L^(−1) based on electrochemical impedance spectroscopy,which were much better than RCs(RC1,69.23%;RC2,74.16%).The adsorption isotherms of TCs on steel were further fitted,and a deep insight on adsorption was discussed.

Multiphase Interfacial Regulation Based on Hierarchical Porous Molybdenum Selenide to Build Anticorrosive and Multiband Tailorable Absorbers

Electromagnetic wave(EMW)absorbing materials have an irreplaceable position in the field of military stealth as well as in the field of electromagnetic pollution control.And in order to cope with the complex electromagnetic environment,the design of multifunctional and multiband high efficiency EMW absorbers remains a tremendous challenge.In this work,we designed a three-dimensional porous structure via the salt melt synthesis strategy to optimize the impedance matching of the absorber.Also,through interfacial engineering,a molybdenum carbide transition layer was introduced between the molybdenum selenide nanoparticles and the three-dimensional porous carbon matrix to improve the absorption behavior of the absorber.The analysis indicates that the number and components of the heterogeneous interfaces have a significant impact on the EMW absorption performance of the absorber due to mechanisms such as interfacial polarization and conduction loss introduced by interfacial engineering.Wherein,the prepared MoSe_(2)/MoC/PNC composites showed excellent EMW absorption performance in C,X,and Ku bands,especially exhibiting a reflection loss of−59.09 dB and an effective absorption bandwidth of 6.96 GHz at 1.9 mm.The coordination between structure and components endows the absorber with strong absorption,broad bandwidth,thin thickness,and multi-frequency absorption characteristics.Remarkably,it can effectively reinforce the marine anticorrosion property of the epoxy resin coating on Q235 steel substrate.This study contributes to a deeper understanding of the relationship between interfacial engineering and the performance of EMW absorbers,and provides a reference for the design of multifunctional,multiband EMW absorption materials.

Polydopamine-modified metal-organic frameworks nanoparticles enhance the corrosion resistance and bioactivity of polycaprolactone coating on high-purity magnesium

Biodegradable magnesium(Mg)and its alloys exhibit excellent biocompatibility and mechanical compatibility,demonstrating tremendous potential for applications in orthopedics.However,the rapid degradation rate has limited their clinical application.Polycaprolactone(PCL)is commonly employed as a polymer coating to impede the rapid degradation of Mg.Unfortunately,its long-term anti-corrosion capability and bioactivity are inadequate.To address these issues,polydopamine(PDA)-modified zeolitic imidazolate framework-8(PZIF-8)bioactive nanoparticles are fabricated and incorporated into the PCL coating.The PZIF-8 particles,featuring catechol motifs,can enhance the compactness of the PCL coating,reduce its defects,and possess biomineralization ability,thereby effectively improving its anti-corrosive and bioactive properties.Moreover,the active substances released from the degradation of the PZIF-8 particles such as Zn^(2+)and PDA are beneficial for osteogenesis.The corrosion tests indicate that the corrosion current density of PCL-treated sample decreases by more than one order of magnitude and the amount of H_(2)released decreases from 0.23±0.12 to 0.08±0.08 ml cm^(-2)after doping with the PZIF-8.Furthermore,the improved corrosion resistance and released PDA and Zn^(2+)from the coating can promote osteogenic differentiation by up-regulating the expression of alkaline phosphatase activity,related osteogenic genes,and proteins.In addition,in vivo implantation experiments in rabbit femur defects further offer strong evidence that the doping of PZIF-8 nanoparticles accelerates bone reconstruction of the PCL coating.In summary,this work implies a new strategy to fabricate a PCL-based coating on Mg-based implants by introducing the PZIF-8 particles for orthopedic applications.

Doublely-doped Mg-Al-Ce-V_(2)O_(7)^(4-)LDH composite film on magnesium alloy AZ31 for anticorrosion

A doublely-doped layered double hydroxide(LDH)film was produced on an anodized magnesium alloy AZ31.The Ce-doped Mg-Al LDH film was prepared by in-situ hydrothermal treatment method,and the intercalation of vanadate was realized by ion-exchange reaction.The structure,morphology and composition of as-prepared LDH film were investigated by X-ray diffractometer,field-emission scanning electronic microscope and energy dispersive spectrometry.Results indicated that a uniform and compact LDH film was formed and the intercalation of Ce^(3+)and vanadate would change the crystal structure of LDHs.The results of the potentiodynamic polarization,electrochemical impedance spectra,hydrogen evolution and corrosion weight loss tests showed the Ce^(3+)and vanadate anions significantly improve the impedance of LDH film,and the active double-doped LDH film could effectively protect the magnesium substrate from corrosion.

Anticorrosion behavior of conversion coatings obtained from unbuffered cerium salts solutions on AA6061-T6

The anticorrosive properties of cerium based conversion coatings deposited on AA6061-T6 alloy by immersion in tmbuffercd cerium chloride and cerium nitrate solutions in the presence of hydrogen peroxide were investigated and characterized by potentiodynamic po- larization （PDP） and electrochemical impedance spectroscopy （EIS） in 0.5 mol/L NaCl aqueous solution. The microstructure and chemical composition of the protective films were examined by scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDS）. It was found that the best corrosion protection was afforded by the samples treated during 600 s in cerium chloride solution at pH values ~5.5-4, showing higher amounts of cerium and polarization resistance values greater than 10 f~ m2. Moreover, an ennoblement of the corro- sion potential and decreasing of the cathodic and anodic currents were obtained compared with the cerium nitrate solutions application. This behavior was attributed to the influence of the deposition parameters such as type of the salt anion, i.e., chelating effect and chaotropic characteristics, pH fluctuations in the conversion solution and deposition time.

Anticorrosion Performance of Epoxy Coatings Containing Small Amount of Inherently Conducting PEDOT/PSS on Hull Steel in Seawater

Corrosion protection of the hull steel by the conventional epoxy paint containing a small amount of commercial poly（3,4-ethylenedioxythiophene）/poly（styrene sulfonate） （PEDOT/PSS）, which is one of the most popular and successful inherently conducting polymers as the corrosion inhibitor was studied. The corrosion behavior of the samples was investigated in seawater by electrochemical impedance spectroscopy and open circuit potential. Scanning electron microscopy was used to observe the surface morphology of the samples after corrosion. It was found that adding a small amount of PEDOT/PSS to the epoxy resin can significantly improve its corrosion protection.

Enhanced Anticorrosion Properties of Epoxy Coatings from Al and Zn Based Pigments

Anticorrosion epoxy coatings from Al and Zn based pigments were synthesized by adjusting their volume ratios, aiming at their increasing anticorrosion performances. The anticorrosion properties were examined via elec- trochemical impedance spectroscopy, Tafel polarization curve analysis and salt spray test. The coating morphologies before and after the salt spray tests were studied via scanning electron microscopy（SEM）. The elemental and chemical compositions of the corroded surfaces of the coatings were analyzed by means of X-ray photoelectron spectroscopy（XPS）. The results indicate that the coating composed of Al/Zn at 10：1（volume ratio） displays the maximum anticorrosion performances, which are superior to those of pristine Al or Zn based pigment.

Graphene-induced enhanced anticorrosion performance of waterborne epoxy resin coating

In this work,waterborne epoxy resin E44 and graphene were employed as the matrix and nanofiller,respectively,to construct composite coatings with enhanced anticorrosion performance.XRD pattern and TEM observation indicated that the obtained graphene had a stacked structure of few-layer graphitic sheets with numbers of wrinkles.SEM observations revealed that no defects or microcracks existed on the surface of graphene/epoxy coatings and the internal micropores and microcracks were filled by graphene.FTIR spectra displayed that all the characteristic absorption peaks were attributed to the epoxy resin cured with polyamide.The Tafel polarization curves showed that,as the graphene addition amount increased,the corrosive potential increased and the corrosive current decreased.ESI results proved that the addition of graphene into epoxy coatings could not only increase the impedance arc in Nyquist plots,but also increase the impedance modulus at low frequency.Finally,the enhanced anticorrosion mechanism was proposed and discussed.

Bio-inspired Superhydrophobic Self-healing Surfaces with Synergistic Anticorrosion Performance

The past decade has witnessed significant efforts in addressing the global metallic corrosion challenge,with a focus on avoiding or mitigating huge economic losses incurred by corrosion and on the development of protective coatings on metals.Herein,a synergistic anticorrosion coating with both superhydrophobicity and self-healing properties was reported,through a facile replica molding method by mixing the polyvinylidene fluoride(PVDF)matrix with nano-sized SiO2 particles and 2-mercaptobenzothiazole(MBT)loaded halloysites(HNTs).The surface exhibits robust self-cleaning behavior under harsh conditions and high liquid repellence to withstand the osmosis of corrosive ions.The self-healing performance of the coating,due to the introduction of MBT-loaded HNTs,enhances the anticorrosion capability,which is still valid once the protective layer is damaged.Potentiodynamic polarization(PDP)and Electrochemical Impedance Spectroscopy(EIS)measurements demonstrate that the synergetic effects in anticorrosion performances significantly enhance the long-term corrosion protection of metals.Hence,this type of dual-action coating may find unique applications in metal corrosion resistance where both super-repellency and self-healing properties are desired.