Surface Analysis Measurements Research Articles

Synergistic inhibition of Mikania micrantha extract with iodide ion on the corrosion of cold rolled steel in trichloroacetic acid medium

The corrosion inhibition behavior of Mikania micrantha extract (MME) and iodide ion in a synergistic system consisting of 0.10 M trichloroacetic acid (Cl3CCOOH, TCA) on cold rolled steel (CRS) materials and its mechanism was fully investigated by weightlessness, electrochemical, and surface analysis measurements. The results show that MME/I− performs higher inhibition than either MME or I− with a peak inhibition efficiency of 96.3 %. The adsorption of MME, I− and MME/I− on CRS follow with Langmuir isotherm. MME/I− retards both anodic and cathodic reactions. With the MME/I− complex inhibitor, the capacitance arc radius reaches a maximum. The results of scanning electron microscopy (SEM), atomic force microscopy (AFM), and confocal laser scanning microscopy (CLSM) showed that there were obvious adsorbent films on the surface of the suppressed CRS. Compositional analysis of surface adsorbates on CRS by X-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectrometry (TOF-SIMS) revealed that the main components of the adsorption film on the surface of CRS contained a large number of polar compounds, notably the formation of chemical bonds by iron atoms.

Newly synthesized based Schiff of phenylferrocene: Molecular and crystal structures, Density Functional Theory calculations, Hirshfeld surface analyses, and improved molecular docking data

In three steps, ferrocene-derived Schiff bases were synthesized, beginning with an arylation reaction, followed by a reduction reaction. The last step describes a condensation reaction between 4-ferrocenylaniline 2a and various aromatic aldehydes in ethanol under reflux. Several techniques were used to determine the structures of the prepared compounds, including 1HNMR , 13CNMR , FTIR, UV/Vis and single crystal X-ray diffraction for compounds 3a, 3f, and 3j. Hirshfeld surface analysis measurements were also performed to measure the interaction energies between molecules. Moreover, the geometric structure of the selected compound (3a, 3f, and 3j) was optimized using a computational analysis involving density functional theory (DFT) calculations based on B3LYP/6–31 G (d, p). Strong binding affinities were observed via both hydrophobic and H-bond interactions with pertinent molecules when molecular docking investigations were conducted on the target crystal structure, the FabX (7e1q). The maximum binding energy is found in the 3d, at -7.99 kcal/mol. Therefore, it is feasible that this structure will work well as a potential lead structure for the synthesis and design of stronger inhibitors that can be used in conjunction with anti-corrosive drugs to treat gastric cancer.

Comparison of fatigue test results of high-strength steel DED-Arc specimens with milled and unmilled surfaces

The surface characteristics of direct energy deposition (DED)-Arc specimens have been previously explored, revealing the dual effect of the surface topography on fatigue strength. This effect includes a reduction in the nominal load-bearing cross-section due to the waviness of the surface and the initiation of fatigue cracks at combined geometric and metallurgical notches from the surface. To complement these findings, this study focuses on the fatigue life and crack initiation of milled DED-Arc samples, e.g., after removal of the geometric notches. Fatigue tests on DED-Arc specimens validate the impact of surface topography on fatigue strength, emphasizing the significance of surface characteristics in determining structural integrity. The additional tests conducted on milled surfaces provide insights into the failure mechanisms specific to these samples. Fracture surface analysis, microstructure characterization, and hardness measurements are performed. For both surface conditions, cracks originate in the interlayer zone, where local hardness is reduced. In unmilled specimens, this is due to the stress concentration effect, and in milled samples, this is due to softened interlayer zones. The fatigue life of milled specimens is comparatively high, demonstrating the importance of optimizing surface characteristics for improved fatigue resistance.Highlights1. Both, unmilled and milled specimens, show crack origins in the interlayer areas. For unmilled specimens, this is because of the local stress concentration in the notch; for milled specimens, it was shown that soft zones between the layers act as the weakest link.2. The fatigue strength of unmilled test coupons is significantly lower than those of milled specimens.3. Unmilled samples exhibit multiple crack origins.

Enhancing Material Analysis with Statistical and Computer Vision Techniques: A Comprehensive Approach for Evaluating Electrode Quality

The optimization of electrodes for electrocatalysis is critical to the efficient operation of energy conversion applications, i.e., performance and efficiency can be improved by optimizing their fabrication process [1]. In the surface microstructure of anodes has been recognized as a fundamental aspect influencing their functionality [2]. Consequently, it is vital to precisely characterize the microstructure of electrodes. Atomic force microscopy (AFM) has demonstrated to be a potent technique for scrutinizing the nanoscale microstructure of anodes. Nevertheless, AFM has limitations in investigating vast areas, thereby posing a challenge when evaluating the surface microstructure of large-scale electrodes.In this study, we developed a multi-stage data quantification method to overcome the limitations of AFM to measure large electrode areas. The efficacy of the developed approach that combines statistical analysis and computer vision techniques was validated by scrutinizing anodes made under various spray coating process conditions. The results demonstrated that the proposed method facilitated the in-depth evaluation of the degree of homogeneity, surface smoothness, and the presence of cracks or defects, thereby enabling a comprehensive assessment of electrode quality. It was possible to establish structure-performance relationships and delineate the interdependence between surface morphology and anode performance, activity, and cycling stability by combining surface analysis measurements with electrochemical analysis.In conclusion, this link between surface and electrochemical analysis will provide critical insights into anode performance and, in turn, drive the development of advanced materials for energy conversion technologies. Therefore, we believe our method has a high potential to expand the material scientist's toolkit and extend its application to analyze the micro/nanostructure of diverse materials in a wide range of applications, providing novel insights for their optimization. References Siegmund, D., et al., Crossing the valley of death: from fundamental to applied research in electrolysis. Jacs Au, 2021. 1(5): p. 527-535.Chatenet, Marian, et al. "Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments." Chemical Society Reviews (2022).

Synergistic effect between sulfate-reducing bacteria and Shewanella algae on corrosion behavior of 321 stainless steel

Microbiologically influenced corrosion (MIC) caused by mixed microorganisms limits the application of 321 stainless steel (SS) in the field of ocean engineering. Therefore, in this paper, the synergistic effect of sulfate-reducing bacteria (SRB) and Shewanella algae (S. algae) on the corrosion behavior of 321 SS was studied by surface analysis and electrochemical measurements. The results revealed that riboflavin secreted by S. algae promoted the electron transfer between SRB and 321 SS by obtaining the electrons generated by the dissolution of metallic iron on the surface of SS and then transferring them to SRB, thus accelerating the MIC of 321 SS. Meanwhile, SRB gained electrons and reacted with SO42− to form HS−, which reacted with iron oxides in the Cr-rich passive film on the surface of SS to generate iron sulfides, providing thermodynamic and kinetic conditions for the formation of Cr6+. The formation of thermodynamically unstable Cr6+ destructed the passive film on the SS surface and promoted the development of pitting corrosion. The outcome provided a new perspective for studying the corrosion mechanism of extracellular electron transfer (EET)-MIC.

Investigation of the post-treatment process for improving corrosion behaviors and adhesion strength of plasma electrolytic oxidation (PEO) coatings on pure copper

The post-treatment processes of plasma electrolytic oxidation (PEO) coatings for corrosion behaviors and adhesion strength are investigated by surface analysis and electrochemical measurements. When the PEO coating is treated with high-temperature oxidation (HTO), silane coupling agent (SCA) mixed with benzotriazole (BTA) exhibits the optimal corrosion behaviors and adhesion strength, the icorr decreases to 0.65 ± 0.35 μA/cm2, ip decreases to 4.37 ± 0.42 μA/cm2, the Epit increases to 369.6 ± 0.4 mVSCE and the bonding strength increases to 14.2 MPa. That was mainly attributed to the corrosive medium with a longer diffusion path to the interface. Moreover, only the HTO treatment at 150 °C showed superior properties for long-time service, the icorr was 2.00 ± 0.17 μA/cm2, ip was 12.30 ± 0.09 μA/cm2, the Epit was −4.7 ± 0.2 mVSCE and the bonding strength was 10.0 MPa. That was ascribed to both the outer hydroxide and the inner oxide depicted the higher compactness.

Determining thermodynamic temperature of sample surface based on area ratio of photoelectron spectrum

The Fermi–Dirac (FD) distribution describes the occupancy of electronic states in a material at thermal equilibrium as a function of the thermodynamic temperature. By measuring the electron energy distribution using photoelectron spectroscopy, we can obtain the FD distribution and determine the thermodynamic temperature. This study proposes a method for determining the thermodynamic temperature, which involves calculating the area ratio between the photoelectron spectra above and below the Fermi level. This thermometric technique offers several advantages, including surface selectivity, noncontact measurement, and coordination with other measuring devices commonly used in surface analysis and nanoscale measurements under ultrahigh vacuum conditions. In this study, we measured the photoelectron spectra near the Fermi level on an Au (110) surface at three different temperatures: liquid nitrogen, liquid helium, and room temperatures. Using the area ratio method, we successfully determined the thermodynamic temperatures with an accuracy of less than 1 K.

Band Bending at CdTe Solar Cell Contacts: Correlating Electro‐Optical and X‐Ray Photoelectron Spectroscopy Analyses of Thin Film Solar Cells

Thin Film Solar Cells In article number 2300073, Darius Kuciauskas and co-workers present a device model for back contacts of CdTe solar cells, using a combination of electro-optical and surface analysis measurements, developed by researchers at NREL and First Solar.

Effect of marine Streptomyces on corrosion behavior of X65 steel in simulated offshore oilfield produced water system

The effects of marine Streptomyces on the corrosion process of X65 steel were investigated by a complete characterization of metabolites using untargeted metabolomics, combined with surface analysis and electrochemical measurements. The results showed that the organic acid produced by Streptomyces accelerated the average corrosion rate of X65 steel in the early stage, but the formation of special “honeycomb” corrosion product structure promoted the enrichment of protein/polysaccharide in metabolites on the metal surface in the middle stage, and the biomineralized film was denser, which slowed down the corrosion especially localized corrosion. In the later stage, the corrosion was intensified due to the shedding of the protective film layer, but no obvious pitting corrosion was observed. In addition, the unique antimicrobial-like metabolites have potential applications in the field of microbiologically influenced corrosion inhibition by microbial control methods.

The effect of HPAM polymer for enhanced oil recovery on corrosion behaviour of a carbon steel and interaction with the inhibitor under simulated brine conditions

The introduction of polymers to reservoir is a common technique for enhanced oil recovery. In this paper, the combination of electrochemical measurements, surface analysis and rheological measurements was employed to elucidate impact of hydrolysed polyacrylamide (HPAM) on corrosion behaviour of carbon steel. The interaction between HPAM and inhibitor was also studied for first time. Adsorption isotherm analysis and XPS implied that corrosion inhibition properties of HPAM are due to chemisorption of polymer on carbon steel surface. Introduction of inhibitor in system resulted in increased viscosity and corrosion inhibition at 25 and 75 °C due to H bonding between HPAM and inhibitor.

Thermal and Bulk Properties of Triblock Terpolymers and Modified Derivatives towards Novel Polymer Brushes.

We report the synthesis of three (3) linear triblock terpolymers, two (2) of the ABC type and one (1) of the BAC type, where A, B and C correspond to three chemically incompatible blocks such as polystyrene (PS), poly(butadiene) of exclusively (~100% vinyl-type) -1,2 microstructure (PB1,2) and poly(dimethylsiloxane) (PDMS) respectively. Living anionic polymerization enabled the synthesis of narrowly dispersed terpolymers with low average molecular weights and different composition ratios, as verified by multiple molecular characterization techniques. To evaluate their self-assembly behavior, transmission electron microscopy and small-angle X-ray scattering experiments were conducted, indicating the effect of asymmetric compositions and interactions as well as inversed segment sequence on the adopted morphologies. Furthermore, post-polymerization chemical modification reactions such as hydroboration and oxidation were carried out on the extremely low molecular weight PB1,2 in all three terpolymer samples. To justify the successful incorporation of -OH groups in the polydiene segments and the preparation of polymeric brushes, various molecular, thermal, and surface analysis measurements were carried out. The synthesis and chemical modification reactions on such triblock terpolymers are performed for the first time to the best of our knowledge and constitute a promising route to design polymers for nanotechnology applications.

Passive film formation and corrosion resistance of laser-powder bed fusion fabricated NiTi shape memory alloys

Electrochemical tests and surface analysis measurements were performed to study the corrosion behavior in a 0.9 wt.% NaCl solution at 37 °C of three NiTi shape memory alloys fabricated by laser-powder bed fusion (L-PBF). The passive film characteristics and corrosion resistance of L-PBF NiTi showed different features as a function of their preparation process settings. The passivation rate for L-PBF NiTi surfaces including defects, such as keyhole pores and cracks which showed high electrochemical activity accelerating the passivation reaction process, was higher in the early stages of immersion, but the corrosion resistance provided by such a rapidly formed passive film containing higher defect density is lower than that for an initially defect-free surface. The thickness of the passive film including a higher defect density does not necessarily relate to the corrosion resistance. The L-PBF NiTi prepared at a linear energy density of 0.2 J/m and volumetric energy density of 56 J/mm3 shows the least defects. Also, an outer Ti-rich and inner Ni-rich dense and corrosion protective passive film could be obtained for these L-PBF NiTi samples, which also results in a relatively low Ni ion release rate. A passive film model based on thickness, composition and defect density properties as a function of processing conditions is proposed to explain the difference in corrosion resistance of the various L-PBF NiTi.

Influence of Metal Cations on Corrosion Behavior of Aluminum Alloy 2024-T3 in Model Freshwater

The influence of metal cations on corrosion behavior of aluminum alloy (AA2024-T3) in model freshwater was examined by immersion experiments, surface analysis, and electrochemical measurements. After long-time immersion, the corrosion rate of AA2024-T3 decreased as the corrosion indicator Y increased, and the corrosion rate of the alloy was reduced by Zn2+. The specimen immersed in Zn2+ containing solution showed less corrosion products which were observed by scanning electron microscopy (SEM). The results of X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) showed that Zn2+ attaches to aluminum alloys and forms protective layers. Electrochemical impedance spectroscopy (EIS) results suggested that Zn2+ reduced the area of defects in the passive film.

Effects of cathodic polarization on X65 steel inhibition behavior and mechanism of mixed microorganisms induced corrosion in seawater

The laws of cathodic polarization on bacterial growth, biofilm formation and effects on the corrosion process of X65 steel were investigated when sulfate-reducing bacteria (SRB) and iron-oxidizing bacteria (IOB) are mixed using surface analysis and electrochemical measurements. Results indicate that insufficient potentials could not inhibit the localized corrosion, but increased the metabolic activities of bacteria. Effective protection could be achieved when the potential was negatively shifted to − 1050 mV vs. SCE. The effects of cathodic polarization on the precess of biofilms formation were also investigated. The − 1050 mV vs. SCE polarization potential could inhibit the biological activity of sessile bacteria, destroy the biofilm structure and inhibit the corrosion process induced by each biofilm.

Electrochemical and computational estimations of cephalosporin drugs as eco-friendly and efficient corrosion inhibitors for aluminum in alkaline solution

In this study, the anionic state of Ceftriaxone sodium (Cefx) and Ceftazidime (Cefz) medication corrosion inhibition capabilities for Al in 0.1 M NaOH solution are explored using various electrochemical analyses. Furthermore, the morphological structure and surface chemical composition of the impact of these drugs on the Al substrate in NaOH are investigated. For the prediction and analysis of interactions between molecule structure and inhibition efficiency, quantum chemical calculations (QC), Monte Carlo simulations (MC), and molecular dynamics (MD) simulations (MD) are performed. The electrochemical findings reveal that the inhibitory effectiveness increases with increasing drug concentrations and declines with rising temperature, reaching a maximum value of 78.4% for 300 ppm Cefx while 59.5% for 300 ppm Cefz at 293 K, implying that Cefx outperforms for Cefz. In addition, the studied drugs act as cathodic inhibitors, and their adsorption is spontaneous and mixed type adsorption in its nature that obeys Freundlich isotherm for Cefz while Temkin isotherm is the best-fitted one for Cefx. Surface analysis and wettability measurements imply that Cefx and Cefz shield the Al against corrosion by surface adsorption and generating a protective hydrophobic film. Thermodynamic activation parameters in the absence and presence of 300 ppm of the studied drugs are calculated and discussed. The energies of the border molecular orbitals and computed molecular parameters for the investigated drugs revealed that anionic Cefx is more readily adsorbed on the Al surface than Cefz. This finding is validated further using MC and MD simulations. Overall, the proposed cephalosporin drugs delivered a cost-effective and facile approach for boosting the efficiency of corrosion inhibitors for Al under aggressive conditions.

Effect of amorphous carbon coating on the formation of solid electrolyte interphase and electrochemical properties of a graphite electrode

Coating graphite negative electrodes of lithium-ion batteries with amorphous carbon layer can significantly improve the battery performance. We investigated the effect of amorphous carbon coating on the formation of a solid electrolyte interphase (SEI) on the graphite surface by performing gas adsorption measurements, surface analysis, and electrochemical impedance measurements. The specific surface area of graphite particles uniformly coated with amorphous carbon is reduced by almost a factor of two, and the irreversible capacity at the first charge/discharge cycle significantly decreases. The SEI film consists of LiF in particulate and O-based coating uniformly distributed at the edges. Hence, the amorphous carbon coating increases the amounts of F and O atoms on the SEI surface and reduces capacitance C′ and the Faraday current at high temperatures. Although the C′ value decreases by approximately 80% after SEI formation, the graphite electrode with an amorphous carbon coating exhibits enhanced C’ retention properties. Because the frequency and temperature dependences of the electrode capacitance are strongly affected by the amorphous carbon coating, an electric double layer is likely formed at the graphite/SEI interface. The difference in capacitive behavior can be attributed to the activity of Li insertion/desorption reaction and capacity fading during storage at elevated temperatures.

Crevice corrosion of X80 carbon steel induced by sulfate reducing bacteria in simulated seawater

Crevice corrosion of X80 carbon steel in simulated seawater with the presence of SRB was studied by surface analysis and electrochemical measurements. The electrode inside crevice was seriously corroded. Large amount of corrosion products accumulated along the crevice mouth. Galvanic current densities measurements confirmed that there was a galvanic effect between the carbon steel at the crevice interior and exterior during the crevice corrosion. The difference in the sessile SRB cells quantities and SRB biofilms developments inside and outside crevice caused the galvanic effect between the carbon steel inside and outside the crevice, which further induced crevice corrosion. Increased crevice width reduced the galvanic effect, resulting in less crevice corrosion in wider crevice.

Optimization of Pickling Solution for Improving the Phosphatability of Advanced High-Strength Steels.

This study investigated the optimum pickling conditions for improving the phosphatability of advanced high-strength steel (AHSS) using surface analysis and electrochemical measurements. To remove the SiO2 that forms on the surface of AHSS, 30 wt.% NH4HF2 was added to the pickling solution, resulting in a significant reduction in the amount of SiO2 remaining on the surface of the AHSS. The phosphatability was improved remarkably using HNO3 concentrations higher than 13% in the pickling solution. Furthermore, phosphate crystals became finer after pickling with a HNO3-based solution rather than a HCl-based solution. Electrochemical impedance spectroscopy (EIS) data indicated that the corrosion resistance of AHSS subjected to HNO3-based pickling was higher than that of AHSS subjected to HCl-based pickling. Fluorine compounds, which were involved in the phosphate treatment process, were only formed on the surface of steel in HNO3-based solutions. The F compounds reacted with the phosphate solution to increase the pH of the bulk solution, which greatly improved the phosphatability. The phosphatability was better under HNO3-based conditions than a HCl-based condition due to the fineness of the phosphate structure and the increased surface roughness.

The Zn2+ Destabilized Surface Film and Accelerated Corrosion of Magnesium

The effect of Zn2+ ions on the corrosion of pure magnesium (Mg) in NaCl solutions was systematically investigated by means of hydrogen evolution, weight loss, surface analysis, polarization curve and solution pH measurements. It was found that the presence of Zn2+ ions in the solution could significantly accelerate the dissolution of Mg. A new mechanism of surface film destabilization was proposed for the detrimental effect of Zn2+ on Mg corrosion, aiming to provide insight into the corrosion behavior of Zn-containing Mg alloys and the galvanic corrosion of Mg alloys coupled by Zn alloys.

Ce addition enhances the microbially induced corrosion resistance of Cu-bearing 2205 duplex stainless steel in presence of sulfate reducing bacteria

Influences of Ce additions (0.08, 0.18 and 0.30 wt.%) on microbiologically influenced corrosion of Cu-bearing 2205 duplex stainless steel (DSS) were investigated through surface analysis and electrochemical measurements during 14-day exposure to a strain of corrosive sulfate reducing bacterium, Desulfovibrio desulfuricans. Results demonstrate the addition of Ce over 0.18 wt.% effectively inhibited the formation of SRB biofilm on surface of 2205-Cu-Ce DSS, and decreased the corrosion tendency to a great degree, indicating that Ce addition over a critical value can significantly enhance antibacterial effect of Cu-bearing 2205 DSS against SRB induced corrosion.