The influence of Methionine (MTI) on corrosion behavior of Twinning induced plastic (TWIP) steel in 3.5wt.% NaCl solutions was investigated using electrochemical techniques, scanning electron microscopy (SEM), white light interferometer (WLI) analyses and Raman spectra. With increasing inhibitor concentration, the corrosion inhibition rate first increased and then decreased, and the maximum inhibitor efficiency was found to be 30 mg l⁻¹ MTI. MTI was acting as a mixed-type inhibitor. The inhibition effect of MTI could also be evaluated by SEM and WLI results, and the trend was the same as that obtained by electrochemistry. At the same time, Raman spectra results showed that MTI was adsorbed on the surface of the steel.

Three thiophenol derivatives with different substituent groups, 2-Naphthalenethiol (2-NT), 4-Chlorothiophenol (4-Cl) and p-Toluenethiol (4-MT) were selected to study the corrosion inhibition performance for copper in saline medium. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) measurements, and weight loss tests were performed to compare the effect of different concentrations and various types of thiophenol derivatives on corrosion inhibition performances. Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and Surface-enhanced Raman spectroscopy (SERS) were utilized to characterize surface morphology and molecular structures of copper samples after corrosion in saline medium or electrochemical tests. Quantum chemical calculations were applied to further investigate the microscopic mechanism of the interaction between thiophenol derivative inhibitor molecules and copper surface. XPS, SERS, and theoretical calculations results indicate that thiophenol derivative inhibitors were adsorbed on Cu surface by Cu–S chemical bond. It was also found that these thiophenol derivative inhibitors could effectively inhibit the corrosion of copper by chemisorption and the efficiency follows the order of 2-NT >4-Cl >4-MT. The larger conjugated aromatic structure in 2-NT may be responsible for the measured higher inhibition efficiency of 2-NT.

Organic/inorganic hybrid perovskite materials, such as CH₃NH₃PbX₃ (X = I, Br), have attracted the attention of the scientific community due to their excellent properties such as a widely tunable bandgap, high optical absorption coefficient, excellent power conversion efficiency, etc. The exposure of perovskite solar cells and photovoltaic devices to heat can significantly degrade their performance. Therefore, elucidating their temperature-dependent optical properties is essential for performance optimization of perovskite solar cells. We synthesized CH₃NH₃PbBr₃ (MAPbBr₃) single crystals through the polymer-controlled nucleation route and investigated the optical properties and molecular structure evolution of them with temperature. Through temperature evolution photoluminescence (PL) spectroscopy, we found that the fluorescence intensity was greatly affected by increasing the temperature, with an asymmetric PL profile suggesting that more captured excitons undergo radiative complexation. The optical photographs showed that the color of MAPbBr₃ single crystals faded. Raman spectroscopy revealed that during the heating process, the structure of MAPbBr₃ was still preserved at 90 °C since all of the Raman bands were very clear. When the temperature increased to 120 °C, the Raman bands of the internal modes became very weak. On further heating, the inorganic framework on sample’s surface started to disintegrate above 210 °C. During the heating process, the PL spectra exhibited significant changes in spectral intensity, peak position and Full Width Half Maximum (FWHM). The PL spectral intensity decreased abruptly with increasing temperature. The peak position was blue shifted with increasing temperature, and the peak shape showed an obvious asymmetry. The FMWH of the PL spectra was gradually broadened with the increase in the temperature, and there was a sharp increase from 270 °C to 300 °C. These variations in the PL spectra with temperature indicate that the optical properties of MAPbBr₃ are greatly affected by temperature, which in turn affects the application of MAPbBr₃ in fields such as optical devices. These results may be instructive for the application of MAPbBr₃.

The long-period stacking ordered (LPSO) structure, functioning as a strengthening phase in magnesium alloys, plays a pivotal role in compensating for inherent performance limitations. In this study, an as-cast Mg-Gd-Ni-Y alloy, including the LPSO phase, was initially obtained through an ingot metallurgy process. Subsequently, the alloy underwent distinct thermal treatments: annealing at 500 °C for 10 h, and extrusion using an extrusion ratio of 10 at a speed of 5 mm/s. Comparative analysis of the microstructure and corrosion characteristics was performed across these three alloy states. Comprising primarily of α-Mg, LPSO phase, and eutectic structures (ES), the alloy exhibited distinctive microstructural features. Immersion experiments conducted in a 3.5% NaCl solution revealed that the as-cast alloy displayed the highest dissolution rate at various temperatures, from room temperature, to 50 °C, and 70 °C. Following annealing, a reduction in the second phase content within the alloy significantly contributed to the observed decrease in its dissolution rate. Extrusion processes resulted in a denser network structure within the microarchitecture, to some extent impeding the spread of corrosion to some extent. By emloying scanning Kelvin probe force microscopy (SKPFM) and micro-electrochemical testing, it was discerned that predominantly the electrochemical system involving α-Mg and the second phases predominantly dictated the heightened dissolution rate of the alloy. This study presents valuable insights into understanding the dissolution mechanisms and potential strategies for controlling the dissolution performance of magnesium alloys containing the LPSO phase.

The corrosion of steel reinforcements substantially degrades the longevity of reinforced concrete structures, particularly in marine settings. This investigation introduces a comprehensive model that simulates the processes involved in moisture and chloride ion transport, rebar corrosion, and the consequent cracking of concrete. The model reveals that the transport dynamics of chloride ions are primarily dictated by their penetration rates through the solution. The sensitivity of the steel to corrosion is a function of the concentrations of water and chloride ions, whereas the rate of corrosion predominantly depends on the availability of oxygen at the corrosive site. Oxygen diffusion is the rate-limiting step in the entire process of the electrochemical reactions of the rebar. And the peak corrosion rates are observed at the interface between the solution and the gas phase. The model calculates the stress and strain in the concrete resulting from volumetric expansion due to oxidization of the steel bars. By accurately reproducing the progression of corrosion-related damage, this model provides crucial insights for predicting the service life of offshore concrete structures and enhancing durability against aggressive environmental conditions.

Calibration is one of the most important factors affecting the measurement accuracy of X-ray energy/wavelength-dispersive spectrometers (EDS/WDSs). In this work, three Cu content reference materials used in AlCu films for X-ray EDS/WDS calibration are prepared using magnetron sputtering deposition. The Cu content standard values of the three reference materials are determined using an inductively coupled plasma optical emission spectrometer (ICP-OES) and the uncertainties of the reference materials are evaluated. The results show that the homogeneity and stability of the three Cu content reference materials used in AlCu films meet the requirements. The Cu content standard values of the three reference materials are 2.56%, 14.64%, and 49.46% (mass fraction), respectively. Their extended uncertainties are 0.14%, 0.42%, and 0.98% (k = 2), respectively. Using quantitative analysis, it was determined that the three developed reference materials meet the calibration requirements of X-ray EDS/WDS, thus guaranteeing the accuracy and consistency of the measurement results.