Interfacial assistant role of amine additives on zinc electrodeposition from deep eutectic solvents: an in situ X-ray imaging investigation

Effect of Pulse Frequency on the Microstructure and the Degradation of Pulse Electroformed Zinc for Fabricating the Shell of Biodegradable Dosing Pump

In this work, we applied single-pulse electrodeposition method to prepare biodegradable zinc coating for the shell of an implantable dosing pump, and explored the effect of pulse frequency on microstructures and degradation behavior of electroformed zinc. Samples were produced by single-pulse electro-deposition technique with different pulse frequencies (50 Hz, 100 Hz, and 1000 Hz). By controlling the pulse frequency, the thickness of the zinc coating can be adjusted. The 50 Hz produced zinc film possesses strong (11.0) grain orientation, 100 Hz produced zinc film possesses clear ((11.0) and (10.0)) grain orientations, yet 1000 Hz produced zinc film shows more random grain orientations of (10.0), (10.1), and (11.0), which provides a possible way to design a controllable nanometer surface microtopography. Although thermodynamic degradation tendency implied from open current corrosion voltage were similar, the kinetic corrosion rate showed a clear increasing trend as pulse frequency increased from 50 Hz to 1000 Hz, which corresponded with the electrochemical impedance spectroscopy and long-term soaking test in hanks solution. According to ISO 10993-5:2009 and ISO 10993-4:2002, electrodeposited zinc materials produced in this study showed a benign hemolysis ratio and no toxicity for cell growth. Zinc prepared under 50 Hz shows the best blood compatibility. Electrodeposited zinc materials are expected to be used for the shell of a degradable dosing pump.

A novel viewpoint of an imidazole derivative ionic liquid as an additive for cobalt and nickel electrodeposition

Thin films of Co and Ni electroplated onto a copper electrode from acidic sulfate and Watts baths, respectively, were investigated. The use of an ionic liquid additive in the electrolyte is widespread for producing thin films by electrodeposition. In the present work, the influence of a new ionic liquid, namely, 1-methyl-3-((2-oxo-2-(2,4,5-trifluorophenyl)amino)ethyl)-1H-imidazol-3-ium iodide (Im-IL), in the electrodeposition of two metals was investigated using cathodic polarization (CP), cyclic voltammetry (CV), and anodic linear stripping voltammetry (ALSV) measurements and cathodic current efficiency (CCE%). The surface morphology of the Co- and Ni-coated samples was examined using Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and atomic force microscopy (AFM). The corrosion protection of the Co and Ni samples in a marine environment (3.5% NaCl solution) was studied by the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results show that the addition of Im-IL inhibits Co²⁺ and Ni²⁺ deposition, which leads to more fine-grained deposits, especially at low Im-IL concentrations. The inhibition of Co²⁺ and Ni²⁺ reduction in the presence of Im-IL ions occurs via adsorption, which obeys the Langmuir adsorption isotherm. The CCE% is higher in the presence of Im-IL. SEM images show smoother deposits of Co and Ni in 1 × 10^-5 M and 1 × 10^-4 M Im-IL solution respectively. The results prove that Im-IL acts as an efficient additive for electroplating soft Co and Ni films.

Tailoring of Versatile Surface Morphologies on Hot Dip Galvanized Steel in Wet CO2: Aspects on Formation, Barrier Properties, and Utilization as a Substrate for Coatings

Zinc carbonate and a mixed-phase zinc carbonate were precipitated selectively on hot dip galvanized steel in the presence of CO₂ and water. The zinc carbonate was precipitated as a uniform layer with cubic superficial appearance, while the mixed-phase zinc carbonate was precipitated as nanowires. The distinct structures could be formed separately or as a dual structure with nanowires on the outermost surface. The barrier properties were improved by the both patina forms; a significant increase in surface hydrophobicity was obtained. The dual patina structure was successfully coated with an organic coating, and the intact wet CO₂-induced patina with both structures was confirmed within the coating. The formed carbonates can be further converted to zinc oxide by calcination, preserving the delicate structures, which opens a wide range of potential applications for the nanostructured ZnO in a variety of future electronic and optoelectronic devices.