Microstructure and Volta-potential analyses were conducted to characterise intermetallic-particles (IMPs) in AA7075-T5. EIS and AFM were applied under operando-conditions to investigate anodisation processes. IMPs have pronounced influence on the growth of anodic aluminium oxide (AAO) films resulting in low charge-transfer resistance. Cu-bearing constituents show cathodic-character, whereas Mg2Si and MgZn2 particles show anodic-character. During anodisation, Al7Cu2Fe remain stable with peripheral-dissolution around boundary. De-alloying of S-phase particles leads to the detachment. Mg2Si undergoes de-alloying at low potential, and re-passivation at high potential. MgZn2 dissolves entirely upon anodization. Localised-dissolution in large-IMPs boundaries or nanometre-sized IMPs facilitates bubble evolution, confirming local breakdown of barrier-layer.

A new strategy was proposed to prepare a composite film using mussel adhesive protein Mefp-1 and graphene to achieve corrosion protection and surface lubrication on carbon steel. The dispersibility of graphene in Mefp-1 solution was firstly investigated and deposition methods of Mefp-1/graphene film were proposed. In-situ confocal Raman micro-spectroscopy and electrochemical impedance spectroscopy measurements were utilized to study the corrosion inhibition effect in NaCl solution. Friction tests were conducted to study the tribological properties. Results show that the Mefp-1/graphene film exhibits strong adhesion to carbon steel, provides improved corrosion- and wear-resistance, and a significantly increased lubricity on carbon steel.

A range of ex situ and in situ analytical techniques were applied to gain insights into the formation and properties of the pre-formed Mefp-1 film on magnesium-1.0 wt.% calcium (Mg-1.0Ca) alloy. The results revealed that the Mefp-1 film pre-formed at pH 4.6 shows a net-like structure, whereas it is more packed at pH 8.5. in situ scanning micro-reference electrode technique results demonstrated the Mefp-1 films formed at both pH can effectively inhibit the localised corrosion of Mg-1.0Ca alloy. Moreover, the film pre-formed at pH 4.6 provides an increasing corrosion inhibition to Mg-1.0Ca alloy during 7 days of exposure.

An imidazolium-based ionic liquid, i.e., 1-Hexadecyl-3-methylimidazolium Bromide (HMIBr), was investigated as a corrosion inhibitor candidate for mild steel in 1 M HCl medium using combined electrochemical and molecular simulation methods. Potentiodynamic polarization results show that HMIBr is a mixed-type inhibitor and suppresses the corrosion process effectively at optimum concentration 10(-3) M with 96.9% inhibition efficiency. Electrochemical impedance spectroscopy (EIS) analysis indicated an increase in the charge transfer resistance with enhance of inhibitor concentration, and confirmed the adsorption of HMIBr on the iron surface. Moreover, density functional theory (DFT) calculations, Monte Carlo as well as molecular dynamics simulations were employed to obtain further insights into the antiseptic mechanism. Our findings have important guiding significance for understanding the corrosion inhibition mechanism and designing new ionic liquid-based inhibitor molecules.

In this work, a novel in-situ grown layered double hydroxide (LDH) film co-intercalated with inhibitors (vanadates) and low surface energy substance (laurates) was immobilized on Al substrates. A long-term monitoring of electrochemical impedance spectra (EIS) of the various samples in 3.5 wt.% NaCl solution demonstrated the synergetic protection of the intercalated two functional species. Meanwhile, the X-ray diffraction (XRD) result of the samples after immersion in NaCl solution for a long time presented the anion-exchange process between vanadates/laurates and chlorides. The synergetic effect of the two species loaded film significantly contributed to the enhanced long-term corrosion protection of aluminum.

3,3-Dithiodipropionic acid (DDA) as a potential corrosion inhibitor for Q235 steel in 0.5 M H2SO4 solution was examined. A variety of research approaches including electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM), atomic force microscopy (AFM), and computational techniques were employed. The toxicity and solubility of DAA were reasonably assessed. Its inhibition efficiency can reach approximately 93% when the optimal concentration is 5 mM. The results of PDP curves manifest that DDA is a mixed type corrosion inhibitor. EIS data indicate that the charge transfer resistance increases with increasing concentration of DDA. Gibbs free energy obtained from the Langmuir isotherm model suggests that DDA molecules hinder the acid attack mainly by chemisorption. Surface topography analysis strongly confirmed the electrochemical findings. Moreover, the simulation results based on density functional theory (DFT) calculation and molecular dynamics (MD) simulations supported the successful interfacial adsorption of DDA on Fe(1 1 0) surface.

Corrosion of steel in concrete has resulted in shorter service life of concrete constructions and it may also cause serious safety accident. Chloride attack and carbonation of the concrete are two of the most crucial trigger factors for the initiation of corrosion. In order to protect the reinforced steel in concrete from corrosion, in this work, a composite inhibitor of layered double hydroxides (LDHs) intercalated with organic phthalates (PTL) and hydroxide ions (MgAl-LDHs-OH-PTL) were synthesized by calcination-reconstruction methods in ambient atmosphere. The structure, composition and morphology of the prepared MgAl-LDHs-OH-PTL were obtained by X-ray diffraction, Fourier transform infrared spectroscopy and Scanning Electron Microscopy, respectively. The electrochemical measurements indicated that the inhibition efficiency of MgAl-LDHs-OH-PTL for carbon steel in the simulated carbonated concrete pore (SCCP) solutions reached more than 90% when its concentration was 20 g/L. It was found that the MgAl-LDHs-OH-PTL possessed multifunctional protection roles for the carbon steel in concrete, which mainly included decrease of aggressive Cl-ions, increase of the pH of SCCP solutions and release of PTL anions to the solution gradually. The work indicated the promising potential of LDHs compounds as effective multifunctional inhibitors in the field of corrosion protection of reinforced concrete.

With the increase in applications of protein-based medicines approved and developed, downstream manufacturing of biopharmaceuticals has challenges of finding cost-effective and reliable routes. Biocrystallization and centrifugation have both been used to isolate and purify macromolecules, such as therapeutic protein and other functional proteins. However, the centrifugation cannot perfectly separate biomolecules, and the biocrystallization mainly focuses on structure determination on a scale of microliters or below. In this work, protein crystallization of lysozyme, with a concentration of 35-45 mg/mL, and sodium chloride, with a concentration of 45-55 mg/mL in the solution, on a scale of milliliters was performed under centrifugation. Different gravity levels of 1-20000g and centrifugation durations have been investigated during the nucleation and crystal growth process. There were no obvious influences of low gravity (<100g) and short duration (<5 min) of centrifugation on the crystallization process: i.e., on the changes in concentrations. With continuous centrifugation (>30 min), high gravity (>1000g) hindered the nucleation, i.e., it reduced the drop in concentration at the nucleation stage; however, it accelerated the crystal growth process, i.e. enhanced a at the crystal growth stage.

Oxygen evolution potential is the determining factor affecting the anode efficiency of the wastewater treatment process. In this study, we focus on increasing oxygen evolution potential of Cr-SnO2/Ti and Cr-Sb-SnO2/Ti electrodes with the pyrolytic method. XRD, SEM and XPS techniques had been applied to characterize the microstructures and chemical compositions of the samples. Electrochemical measurements had been performed to evaluate the oxygen evolution potential as a criterion of the wastewater treatment efficiency. The results show that co-doping of Sb and Cr improved the crystallinity and grain size of SnO2 coating, and Cr existed in the form of Cr(III) valence states. The Cr doping treatment improved the electronic conductivity and the electrocatalytic activity of the electrodes. DFT calculation of the band-structure indicates Cr doped SnO2 had a superior electrical conductivity, where Cr atom acts as an acceptor providing vacancies for electron transportation. The DOS diagrams reveal the Cr doped SnO2 showing a p-type conductivity which would subsequently influence the built-in potential on metal-semiconductor interface. We proposed the mechanism of the increase of oxygen evolution potential is the doping of Cr expands the built-in potential.

This work provides insight into the fabrication of ZnAl layered double hydroxides (LDHs) intercalated with organic phthalates (PTL) and their corrosion protection of steel reinforced concrete. The structure, composition and morphology of the LDH products prepared by various methods were systematically characterized to find out the relationship of preparation-structure-properties. The ZnAl-LDH-PTL prepared by co-precipitation method presented the best performance of corrosion protection due to its good crystallinity. The corrosion protection mechanism of LDH for steel in concrete system was also discussed.