Hybrid superamphiphobic anti-corrosion coating with integrated functionalities of liquid repellency,self-cleaning,and anti-icing

Superhydrophobic materials have shown tremendous potential in various fields.However,the adhesion,wetting,and pinning of low-surface-tension liquids greatly limit their multifunctional applications.Therefore,the creation of superamphiphobic coatings that combine superhydrophobic and superoleophobic properties through a simple preparation strategy is desirable.In this study,we successfully developed an organic-inorganic hybrid superamphiphobic coating on Q235 carbon steel using aluminum oxide nanopar-ticles,organosilanes,and waterborne epoxy resin via a versatile spray-coating technique.The coating ex-hibited high contact angles(>151°)and low sliding angles(<7°)for water and oil liquids,demonstrating excellent superamphiphobic characteristics.Electrochemical tests demonstrated significant improvements in charge transfer resistance and low-frequency modulus for the superamphiphobic coating.The corro-sion potential shifted positively by 590 mV,and the corrosion current density decreased by four orders of magnitude.Additionally,the coating endured 480 h of salt spray and 2400 h of outdoor atmospheric exposure,showcasing superior anti-corrosion capacity.Freezing tests of water droplets at-10°C and-15°C confirmed that the coating significantly prolonged the freezing time with reduced ice adhesion strength.We believe that the designed superamphiphobic coating with integrated functionalities of selfcleaning,anti-corrosion,anti-icing,and anti-liquid-adhesion can provide important solutions for extending the lifespan of materials in marine and industrial environments.

The corrosion characteristic and mechanism of Mg-5Y-1.5Nd-xZn-0.5Zr(x=0,2,4,6 wt.%)alloys in marine atmospheric environment

The microstructure and precipitated phases of as-cast Mg-5Y-1.5Nd-x Zn-0.5Zr(x=0,2,4,6 wt.%)alloys were investigated by optical microscopy,scanning electron microscopy,energy-dispersive spectrometry and X-ray Diffraction.The exposure corrosion experiment of these magnesium alloys was tested in South China Sea and KEXUE vessel atmospheric environment.The corrosion characteristic and mechanism of magnesium alloys of Mg-5Y-1.5Nd-x Zn-0.5Zr(x=0,2,4,6 wt.%)alloys were analyzed by weight loss rate,corrosion depth,corrosion products and corrosion morphologies.The electrochemical corrosion tests were also measured in the natural seawater.The comprehensive results showed that Mg-5Y-1.5Nd-4Zn-0.5Zr magnesium alloy existed the best corrosion resistance whether in the marine atmospheric environment and natural seawater environment.That depended on the microstructure,type and distribution of precipitated phases in Mg-5Y-1.5Nd-4Zn-0.5Zr magnesium alloy.Sufficient quantity anodic precipitated phases in the microstructure of Mg-5Y-1.5Nd-4Zn-0.5Zr alloy played the key role in the corrosion resistance.

Double enzyme mimetic activities of multifunctional Ag nanoparticle-decorated Co_(3)V_(2)O_(8)hollow hexagonal prismatic pencils for application in colorimetric sensors and disinfection

Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like materials.In this work,Co_(3)V_(2)O_(8)with hollow hexagonal prismatic pencil structures were prepared as novel artificial enzyme mimics.They were then decorated by photo-depositing Ag nanoparticles(Ag NPs)on the surface to further improve its catalytic activities.The Ag NPs decorated Co_(3)V_(2)O_(8)(ACVPs)showed both excellent oxidase-and peroxidase-like catalytic activities.They can oxidize the colorless 3,3’,5,5’-tetramethylbenzidine rapidly to induce a blue change.The enhanced enzyme mimetic activities can be attributed to the surface plasma resonance(SPR)effect of Ag NPs as well as the synergistic catalytic effect between Ag NPs and Co_(3)V_(2)O_(8),accelerating electron transfer and promoting the catalytic process.ACVPs were applied in constructing a colorimetric sensor,validating the occurrence of the Fenton reaction,and disinfection,presenting favorable catalytic performance.The enzyme-like catalytic mechanism was studied,indicating the chief role of⋅O_(2)-radicals in the catalytic process.This work not only discovers a novel functional material with double enzyme mimetic activity but also provides a new insight into exploiting artificial enzyme mimics with highly efficient catalytic ability.

Anisotropy of the crystallographic orientation and corrosion performance of high-strength AZ80 Mg alloy

A high-strength AZ80 Mg alloy was prepared through multi-direction forging,thermal extrusion,and peak-aged heat treatment.The microstructure,crystallographic orientation and corrosion performance of extrusion-direction,transverse-direction,and normal-direction specimens were investigated using scanning electron microscopy,electron backscatter diffraction,and atomic force microscopy,respectively.Experimental results showed that crystallographic orientation significantly influenced the corrosion performance of AZ80 Mg alloy.Corrosion rates largely increased with decreased(0001)crystallographic plane intensity,whereas the(10−10)and(2−1−10)crystallographic plane intensities increased.This study showed that the corrosion rates of alloy can be modified to some extent by controlling texture,thereby promoting the applications of high-strength AZ80 Mg alloys in the aerospace and national-defense fields.

Polyaspartic acid as a corrosion inhibitor for WE43 magnesium alloy

The inhibition behavior of polyaspartic acid(PASP)as an environment-friendly corrosion inhibitor for WE43 magnesium alloy was investigated in 3.5 wt.%NaCl solution by means for EIS measurement,potentiodynamic polarization curve,and scanning electron microscopy.The results show that PASP can inhibit the corrosion of WE43 magnesium alloy.The maximum inhibition efficiency is achieved when PASP concentration is 400 ppm in this study.

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.

Triazole derivatives as corrosion inhibitors for mild steel in hydrochloric acid solution

The title compounds 1-（4,5-dihydro-3-phenyl pyridine-1-yl）-2-（1H-1,2,4-triazole-1-yl） ethyl ketones were studied as a corrosion inhibitor in a mild steel in 1 mol /L hydrochloric acid solution using weight loss measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy （EIS）. Results indicated that these compounds had excellent inhibition properties. Polarization curves indicated that the inhibitor behaved mainly as mixed-type inhibitor. The EIS results showed that the charge transfer controlled the corrosion process in the uninhibited and inhibited solutions. Adsorption of the inhibitor on the mild steel surface followed Langmuir＇s adsorption isotherm with negative value of the free energy of adsorption ΔGads^o. The thermodynamic parameters of adsorption were determined and discussed.

The corrosion behavior of Mg-Nd binary alloys in the harsh marine environment

The corrosion behavior of Mg-Nd binary alloys in the harsh South China Sea environment was researched by scanning electron microscopy,energy-dispersive spectrometry and X-ray diffraction analysis.In order to explain the corrosion mechanism,corrosion resistance was analyzed by weight loss rate and electrochemical measurement in the laboratory.With a continuous enlargement of Nd-content,Mg 12 Nd phases increased and multiplied.The weight loss rate of Mg-0.5Nd alloy was 0.0436 mg·cm^(-2)·y^(-1)(0.0837 mm·y^(-1)),whereas that of Mg-1.5Nd alloy was 0.0294 mg·cm^(-2)·y^(-1)(0.0517 mm·y^(-1))during the exposure corrosion in the South China Sea site.The mechanical strength of Mg-1.5Nd alloy was 148 MPa before the exposure in the harsh marine environment,while the residual mechanical strength was merely about 94 MPa after the exposure test.Both Mg-1.5Nd alloy and Mg-1.0Nd alloy occurred the brittle fracture,which resulted that the elongation was nearly equal to zero.The self-corrosion current density demonstrated that degradation rate of Mg-Nd binary alloys was as follows:Mg-0.5Nd>Mg-1.0Nd>Mg-1.5Nd.For the South China Sea corrosion site,a large amount of sea salts exited in the atmospheric environment.Due to the heavy rainfall and high humidity,sodium chloride in the atmospheric environment dissolved,more serious electrochemical corrosion occurred on the surface of Mg-Nd binary alloys.

Corrosion behavior of Mg-8Li-3Zn-Al alloy in neutral 3.5%NaCl solution

The corrosion behavior of Mg-8Li-3Zn-Al alloy was investigated in neutral 3.5%NaCl aqueous solution by morphology observation and electrochemical tests.The weight loss method was to measure the corrosion rate.The electrochemical results indicated that the corrosion resistance of Mg-8Li-3Zn-Al alloy in 3.5%NaCl solution is poorer than that in distilled water.The Cl-anion leads to the initiation and development of the corrosion pits.And the corrosion products are mainly Mg(OH)_(2).

The corrosion behavior and mechanical property of the Mg-7Y-x Nd ternary alloys

The corrosion behavior and mechanical property of Mg-7Y-x Nd(x=0.5,1.0,1.5 wt%)alloys were investigated.The microstructure and precipitations of Mg-7Y-x Nd alloys were studied by scanning electron microscopy,energy-dispersive spectrometry and X-ray Diffraction.The quantities of the Mg_(12)(Y,Nd)phase increased,whereas that of the Mg_(24)(Y,Nd)_(5)phase decreased with increasing Nd-content.The weight loss rate decreased from 17.5020 mg cm^(-2)·d^(-1)(36.7542 mm y^(-1))to 9.3744 mg cm^(-2)·d^(-1)(19.6862 mm y^(-1)).The electrochemical measurement also demonstrated the similar tendency.The loss in mechanical properties after corrosion reaction followed the order Mg-7Y-0.5Nd>Mg-7Y-1.0Nd>Mg-7Y-1.5Nd.The precipitations played dual roles in the corrosion resistance that depended on type and distribution.

Effect of Sulfate-reducing Bacteria on Corrosion Behavior of Mild Steel in Sea Mud

Microbiologically influenced corrosion （MIC） is very severe corrosion for constructions buried under sea mud environment. Therefore it is of great importance to carry out the investigation of the corrosion behavior of marine steel in sea mud. In this paper, the effect of sulfate-reducing bacteria （SRB） on corrosion behavior of mild steel in sea mud was studied by weight loss, dual-compartment cell, electronic probe microanalysis （EPMA）, transmission electron microscopy （TEM） combined with energy dispersive X-ray analysis （EDX） and electrochemical impedance spectroscopy （EIS）. The results showed that corrosion rate and galvanic current were influenced by the metabolic activity of SRB. In the environment of sea mud containing SRB, the original corrosion products, ferric （oxyhydr） oxide, transformed to iron sulfide. With the excess of the dissolved H2S, the composition of the protective layer formed of FeS transformed to FeS2 or other non-stoichiometric polysulphide, which changed the state of the former layer and accelerated the corrosion process.

A universal design for triggering the precise micro-structure reconstruction through in-situ electro-regulating to boost the pseudocapacitance of MnO_(2)

Developing a precise controllable strategy for modulating the micro-morphology,atom coordination environment,and electronic structure of electrode materials is crucial for the performance in the field of energy storage,yet still a tremendous challenge.Herein,a facile and universal in-situ electrochemical self-optimization design,electro-regulating,is designed to controllably produce electrode materials with abundant defects.Through detailed characterization studies,the microstructure of MnO_(2) is reconstructed after electro-regulating,which exhibits a structure of small fragments with numerous holes due to the partial self-dissolution of acidic oxides under an alkaline operating environment.Furthermore,the electro-regulating strategy not only presents the formation steps of numerous holes but is also accompanies by a number of O vacancies generation process due to the activation of an external electric field.This study provides a new inspiration for reasonably designing advanced functional electrode materials for various electrochemical applications and beyond.

Developing high photocatalytic antibacterial Zn electrodeposited coatings through Schottky junction with Fe3+-doped alkalized g-C_(3)N_(4) photocatalysts

Pure Zn coatings easily lose their protective performance after biofouling because they have no antibacterial effect under visible light.In this study,we fabricate a new antibacterial Zn composite coating using electrodeposition to couple Fe3+-doped alkalized g-C_(3)N_(4)(AKCN-Fe)into an existing Zn coating and show that the AKCN-Fe enhances antibacterial property of the Zn coating under visible light.We attribute this enhancement to the high photocatalytic performance,high loading content,and good dispersion of AKCN-Fe.In addition,the photocatalytic antibacterial mechanism of the composite coating is supported by scavenger experiments and electron paramagnetic resonance(EPR)measurements,suggesting that superoxide(·O_(2)^(-))and hydroxyl radical(·OH)play main and secondary roles,respectively.

Preparation of low-fouling reverse-osmosis membranes on an Al2O3 carrier for desalination exploratory research

The surface of an α- AI2O3 carrier for semi-permeable zeolite membranes was modified with copper via an electroless plating process. Following hydrothermal synthesis, dense and highly organized zeolite membranes were obtained. Membrane thickness was confined to the nanoscale following layer-by-layer self-assembly of polyelectrolytes with opposite charges. This con trollable and low-cost preparati on method could drastically reduce the cost of fabricating reverse osmosis membranes, which is highly significant for the realization of large-scale seawater desalination through reverse osmosis. Understa nding the in fluences of interacti ons between various ions and the zeolite pores, in ter-crystalli ne gaps, membrane structure and surface chemical properties, transmembrane pressure, and temperature on the desalination process will help provide a theoretical basis and referenee point for the development of reverse osmosis membranes.

Double layered superhydrophobic PDMS-Candle soot coating with durable corrosion resistance and thermal-mechanical robustness

Nature-inspired superhydrophobic coatings with typical Cassie-Baxter contacts garner numerous interests for multifunctional applications.However,undesirable poor mechanical and thermal stability are still crucial bottlenecks for real-world employment.This work introduces a cost-effective,fluorine free and versatile strategy to achieve double-layered PDMS agglutinated candle soot coating with superior water-repellent superhydrophobicity.The surface morphologies,chemical compositions and wettability behaviors were investigated in detail.The mechanical stability,chemical stability and durable corrosion resistance of the fabricated PDMS-CS coating were evaluated through friction,calcination and electrochemical impedance spectroscopy.The results demonstrate a remarkably enhanced mechanical robustness and corrosion resistance,indicating PDMS units can act as an effective agglutinating agent between candle soot and underlying substrate.The synergistic effect of PDMS agglutination,porous network nanostructures and extremely low surface energy of incomplete combustion induced candle soot deposition contribute to the eventually robust corrosion resisting coating,which greatly increases the possibility for practical applications.

Interaction between sulfate-reducing bacteria and aluminum alloys——Corrosion mechanisms of 5052 and Al-Zn-In-Cd aluminum alloys

Microbiologically influenced corrosion caused by sulfate-reducing bacteria(SRB) poses a serious threat to marine engineering facilities.This study focused on the interaction between the corrosion behavior of two aluminum alloys and SRB metabolic activity.SRB growth curve and sulfate variation with and with aluminum were performed to find the effect of two aluminum alloys on SRB metabolic activity.Corrosion of 5052 aluminum alloy and Al-Zn-In-Cd aluminum alloy with and without SRB were performed.The results showed that both the presence of 5052 and Al-Zn-In-Cd aluminum alloy promoted SRB metabolic activity,with the Al-Zn-In-Cd aluminum alloy having a smaller promotion effect compared with 5052 aluminum alloy.The electrochemical results suggested that the corrosion of the Al-Zn-In-Cd aluminum alloy was accelerated substantially by SRB.Moreover,SRB led to the transformation of Al-Zn-In-Cd aluminum alloy corrosion product from Al(OH)3 to Al2 S3 and NaAlO2.

Poly(dimethyl siloxane)anti-corrosion coating with wide pH-responsive and self-healing performance based on core-shell nanofiber containers

In this research,core-shell electrospun fibers loaded with the shell of cellulose acetate and the core of oleic acid and alkyd varnish resin were synthesized and used within poly(dimethyl siloxane)(PDMS)to prepare self-healing and p H-responsive coatings for a steel substrate.The morphology of the electrospun fibers was characterized by scanning electron microscopy,transmission electron microscopy and confocal fluorescence microscopy.Thermo gravimetric analysis and Fourier transform infrared spectroscopy revealed that the self-healing agents were loaded successfully with a loading rate of 2.9%.The properties of the fiber-PDMS composite coating were characterized by water contact angle measurements,mechanical tests,electrochemical impedance spectroscopy,and scanning Kelvin probe.Results show that the maximum self-healing efficiencies of the fiber-PDMS coating in alkaline and acidic solution are 95.96%and 97.04%,respectively.The composition of the self-healing agents at the damaged part of the coating was verified by an infrared mapping test and using an energy dispersive spectrometer.In addition,the sandpaper abrasion test shows the hydrophobic effect of fiber-PDMS coating remains above 88.2%and decreases slightly through the addition of abrasion cycles.This research can pave the way for the industrial applications of p H-responsive self-healing coatings.

Enhanced photoelectrochemical cathodic protection performance of MoS_(2)/TiO_(2)nanocomposites for 304 stainless steel under visible light

In this work,TiO_(2)nanotube arrays(NTAs)sensitized with MoS_(2)microspheres(MoS_(2)/TiO_(2)nanocomposites)were prepared on a flat Ti substrate via two-step anodization and hydrothermal method sequentially.TiO_(2)NTAs were composed of many orderly nanotubes,whose large specific surface area was favorable for light absorption and MoS_(2)microsphere adhesion.The MoS_(2)microsphere as a narrow band gap semiconductor extended the TiO_(2)NTAs’absorption band edge to the visible region.The 2D structure of MoS_(2)microspheres and the construction of heterojunction electronic field at the interface of MoS_(2)microspheres and TiO_(2)NTAs promoted the separation of photoinduced carriers.The MoS_(2)/TiO_(2)nanocomposites could provide higher photoelectrochemical cathodic protection for 304 stainless steel(304 SS)under visible light than pristine TiO_(2)NTAs.

Preparation of Ag@CuFe_(2)O_(4)@TiO_(2) nanocomposite films and its performance of photoelectrochemical cathodic protection

A Ag@CuFe_(2)O_(4)@TiO_(2) nanocomposite film with high performance of photogenerated cathodic protection was prepared by hydrothermal and photoreduction methods.The results showed that when the CuFe_(2)O_(4) hydrothermal reaction time was 6 h and the AgNO_(3) concentration was 0.1 M,the Ag@CuFe_(2)O_(4)@TiO_(2) nanocomposite material performed the best cathodic protection capability for 304 stainless steel(304SS).In this case,the protective potential achieved-930 mV(versus SCE)associated with the photocurrent density of 475μA/cm^(2),which was 14.8 times that of pure TiO_(2) nanowires.In the dark,the nanocomposite provided cathodic protection of up to 485 mV for 304SS.Due to the heterogeneous junctions at the two interfaces among the three kinds of nanocomposite materials,the build-in electric field was fabricated,which promoted the separation efficiency of photogenerated electrons and holes and effectively improved the photochemical cathodic protection of 304SS.

Facile fabrication of self-healing silicone-based poly(urea-thiourea)/tannic acid composite for anti-biofouling

A novel silicone-based poly(urea-thiourea)/tannic acid composite(PDMS-P(Ua-TUa)-TA)with excellent mechanical,self-healing and antifouling properties is developed.The multiple dynamic hydrogen bonds formed by thiourea groups,urea groups,and tannic acid(TA)molecules ensured a tough elastomer(ultimate strength:2.47 MPa)with high stretchability(~1000%).TA molecules as partial hydrogen bonding cross-linking sites interacted rapidly with urea and thiourea groups before the migration of polymer chains,resulting in fast and efficient self-healing.Scratches on the film completely disappeared within12 min,and the repair efficiency of strength was up to 98.4%within 3 h under ambient condition.Selfhealing behavior was also evaluated in artificial seawater and the healing efficiency(HE)was 95.1%.Furthermore,TA uniformly dispersed in the polymer matrix provides good antibacterial and anti-diatom properties,as well as strong adhesion to the substrate(~2.2 MPa).Laboratory bioassays against marine bacteria adhesion(~96%,~95%and~93%reduction for P.sp.,E.coli,and S.aureus,respectively)and diatom attachment(~84%reduction)demonstrated an outstanding antifouling property of the PDMSP(Ua-TUa)-TA.This work provides a promising pathway towards the development of high-performance silicone-based coatings for marine anti-biofouling.