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Three species of diamond-like carbon (DLC) film were systematically examined in NaCl solution for their anticorrosion properties. Si&N&H-DLC has better electrochemical characteristics and salt spray corrosion testing results than the substrate and two species DLC films in NaCl solution. Due to the successive growth of Si, N, and H-DLC, there is a well-bonded Si–N interface and the formation of Si oxides. The Si&N&H-DLC film exhibits extremely high charge transfer resistance, exceeding 106 Ω/cm2. A salt spray test shows that the Si&N&H-DLC film presents a lower rate in NaCl solution in comparison to the substrate and the other two species of DLC films. As a result, the Si&N&H-DLC film significantly improved the corrosion performance of the substrate. [ABSTRACT FROM AUTHOR]

In this study, the superhydrophobic epoxy resin coating with siloxane-modified carbon nanotubes was prepared. Hydroxylated multi-walled carbon nanotubes (HMWCNTs) were modified with siloxane to make them superhydrophobic, which were mixed with epoxy resin to prepare an excellent superhydrophobic coating on the surface of AH36 carbon steel. Highly silanized HMWCNTs (HSHMWCNTs) were added to hydrophobic isobutyl groups and amino groups that can bond with epoxy resin. The results show that the water contact angle (WCA) of HSHMWCNTs is >170°. The coating has a WCA of 157.2° and a water sliding angle of 6° when the addition of the HSHMWCNTs reaches 70 %. The coating has excellent self-cleaning properties and remains superhydrophobicity under tape-peeling for 90 times. When the coating has a superhydrophobic effect, there is an air layer on the surface, improving the corrosion resistance of the coating. [Display omitted] • Groups bonding to the coating are attached on CNTs to improve durability. • Stirring or ultrasonic superhydrophobic coatings are characterized. • They remained superhydrophobicity under tape-peeling for 90 times. • Fluoride use was eliminated. [ABSTRACT FROM AUTHOR]

The corrosion behavior of a medium-Mn steel in a simulated marine splash zone was studied by a dry–wet cyclic corrosion experiment and electrochemical experiment. The corrosion products were characterized by corrosion rate calculation, composition detection, morphology observation, element distribution detection, valence analysis, polarization curve, and electrochemical impedance test. The results show that the corrosion products of the sample mainly include γ-FeOOH, FexOy, MnxOy, and a small amount of (Fe,Mn)xOy, and the valence state of iron compounds and manganese compounds in different corrosion stages changed obviously. In the initial corrosion products, Mn is enriched significantly and facilitates the electrochemical reaction of corrosion process. The content of Ni in the inner rust layer is high. The semi-quantitative analysis of the corrosion product elements shows that the atomic concentrations of Cr and Mo increase significantly in later corrosion products, indicating that the dense isolation layer formed by alloy element compounds in the corroded layer is the main factor to improve the protection ability of the rust layer at the end corrosion stage of the sample. With the corrosion durations, the corrosion current density of the sample with the corrosion product film first increases and then decreases, and the corrosion potential first moves negative and then shifts in a positive direction subsequently, indicating that the protective effect of the corrosion product film is gradually significant. [ABSTRACT FROM AUTHOR]

Mechanical properties of Q370qE carbon steel can be improved by cladding it with 316L stainless steel. After rolling these materials together, microstructure, hardness, shear strength, and corrosion properties of the cladded metals were evaluated. Hardness and shear tests were performed according to appropriate standards to evaluate the bonds. The results show that the remarkable diffusion of Ni and Cr formed a hard transition zone. The width of this diffusion zone increases with increasing temperature. The shear strength of the clad interface reached a minimum of 385 MPa. In addition, the surfaces of samples were examined by neutral salt spray (NSS) tests and potentiodynamic polarization tests to examine corrosion behavior. The 316L side primarily exhibited pitting corrosion, while the Q370qE side was dominated by uniform corrosion. [ABSTRACT FROM AUTHOR]

For degradable magnesium alloy stents, excellent corrosion resistance and rapid endothelialization are two essential properties. In this paper, we plan to use a copper-loaded chitosan coating to accelerate the endothelialization process of the stent, which not only improves the biocompatibility of the magnesium alloy stent, but also its corrosion resistance by improving the service environment in vivo. Copper is an impurity in magnesium alloys, so how copper-containing coatings affect the corrosion resistance of magnesium alloy stents is the focus of this paper. The corrosion properties of the material were characterized by electrochemical experiments, immersion experiments, and in vitro cellular experiments characterized the effect of the copper-loaded coating on endothelial cells. The results showed that the I corr of the copper-loaded chitosan coated sample and the I corr of the unloaded copper chitosan coated sample were both in the order of 10−8, and the decrease of the corrosion resistance of the magnesium alloy by the copper-containing chitosan composite coating was not significant, and it still had a protective effect on the magnesium alloy substrate. During the immersion process, magnesium and copper ions were slowly released, followed by the hydrogen released. In addition, the weight loss rate of different coated samples presented the tendency of slower at inital, faster at last, and the weight loss rate of 0.041% for the copper-loaded chitosan coated sample was not significantly different from that of 0.035% for the unloaded copper coating group, after 28 days of immersion. The in vitro degradation products of the copper-loaded composite coating on the surface of magnesium alloy were also analyzed by XRD and EPMA, which included M g (O H) 2 , M g 3 (P O 4) 2 and C a 3 (P O 4) 2 ; in addition the degradation process was analyzed. The cellular experiments results showed that the copper-loaded magnesium alloy had a proliferation rate of 243.0% for endothelial cells, which indicated that the copper-loaded coating could endow magnesium alloy stent a good biofunctional properties. • For endowing biofunction to Mg alloy stent, a copper-loaded chitosan coating is prepared on its surface for the first time. • The copper ion loaded to coating does not effect corrosion resistance of magnesium alloys significantly. • It is inferred that copper-loaded coating endows the magnesium alloy material excellent endothelialization potential. • The degradation mechanism of magnesium alloy treated by copper-loaded coating is elucidated. [ABSTRACT FROM AUTHOR]

It is well known that polyaniline is a promising electrode material because of its high capacitance, controllable morphology and fast Faradaic reaction, however, its swelling and shrinking behavior during charge/discharge processes may cause structure collapse, leading to the poor cycling stability. In this article, a series of polyaniline/Fe(OH)3/graphene (PFG) nanocomposites were synthesized using a facile interfacial polymerization method under acid condition by adjusting the polymerization time. During the interfacial polymerization process, graphene oxide and ferric chloride acted as oxidants, while aniline acted as reducing agent. The results indicated that the PFG nanocomposite polymerized at 48 h (PFG48) demonstrated the highest specific capacitance of 417 F·g-1 at 1 A·g-1, and a good stability with 71.2% capacitance retention after 5000 cycles. The excellent electrochemical properties can be ascribed to the optimal microstructure and morphology of PFG48 prepared at the suitable polymerization time. [ABSTRACT FROM AUTHOR]