1,721,044 research outputs found
Electrodeposition of indium from a deep eutectic solvent
Full text linkIn this work the suitability of 1:2 choline chloride/urea deep eutectic solvent (DES) for the electrodeposition of indium has
been studied. During deposition, temperature was kept constant at 80°C in favor of mass transfer rate and to lower the
viscosity of the solution as well. Voltammetric experiments showed typical overpotential governed nucleation of indium. It
was also found with chronoamperometry that electrodeposition of indium at molybdenum electrode proceeds via
instantaneous nucleation with diffusion controlled growth, while at gold electrode the deposition proceeds via progressive
nucleation with diffusion-controlled growth. EDX analysis and XRD patterns revealed that the deposits were pure crystalline
indium for all the cases. The deposits exhibited polygonal shaped grains at low current density and nodular morphology with
rounded grains at higher current density
Fundamentals and application of electrowetting on dielectrics
Full text linkA review of the electrowetting EW phenomenon and its applications is provided. The state of the art includes already implemented technologies like EW displays or variable focus lenses but also laboratory level researches in the lab-on-chip and fluid manipulation field. In the second part of the work some preliminary experimental results are provided for the electrowetting on fluoropolymer coated anodized aluminum, as example of EWOD electrowetting on dielectrics. Anodization was performed in weakly acidic or neutral 2% wt. boric acid solution in water with an applied voltage range between 10 and 40 V, then coating the surface with AF 1600. Experimental electrowetting data fit with the Young-Lippmann relation, confirming aluminum as a promising material for electrowetting applications
Electrodeposition of indium phosphide from an ionic liquid for photovoltaics
Full text linkIn this study the suitability of 1:2 choline chloride/urea Deep Eutectic Solvent (DES) for the electrodeposition of indium
phosphide (InP) has been investigated. Deposition temperature was kept constant at 80°C to favor mass transfer rate and
to lower viscosity of the solution. XRD patterns demonstrated presence of indium (In) only. On the contrary, EDX analyses
revealed presence of indium (In) along with very small amount of phosphorous (P) from some deposits. An alternative way
of producing InP was also examined in this study. That was electrodeposition of pure In from 1:2 choline chloride/urea Deep
Eutectic Solvent (DES) and subsequent phosphorization in phosphine (PH3) gas. The XRD patterns confirmed the formation
of InP. Optical characterizations of the phosphorized sample (Photoluminescence (PL) and Time-Resolved
Photoluminescence (TRPL)) showed promising results for its use as photovoltaic (PV) application
Electrodeposition of supersaturated CuAg alloys in pyrophosphate-iodide electrolytes
Full text linkA novel electrolyte based on CuSO4 complexed by K4P2O7 and AgNO3 complexed by KI is studied for the deposition of CuAg alloys having a range of Ag compositions between 3 %at. and 16 %at. The deposition occurred in non stirred conditions at 50°C. A characterization of the coatings is presented with a focus on the properties of the supersaturated alloy and the demonstration of its metastable behavior. The electrochemical characterization of the solution is also reported
Copper electrodeposition from a chloride free deep eutectic solvent
Full text linkThe possibility of substituting choline chloride in the well-known choline chloride/ethylene glycol deep eutectic solvent is studied in the article. The substitution with choline dihydrogencitrate gives the possibility tomaintain the choline moiety and to obtain an electrolyte free of chloride ions. Different ratios between choline dihydrogencitrate and ethylene glycol are tested to analyze the effect of this parameter on the behavior of the solution. Physical characterization and electrochemical investigation of the pure and the copper supplemented electrolytes are provided to properly link the chemistry of the electrolytes with their physical properties and their influence onmetal electroreduction. Fromthis point of view viscosity and conductivity of the new solutions are analyzed, highlighting a strong influence of the first on the possibility of good quality metal plating. Copper deposition is successfully attempted on nickel and the resulting coatings are analyzed bymean of SEM, hardness measurements, XRD and microprofilometry. Good quality coatings can be easily obtained from a choline dihydrogencitrate/ethylene glycol deep eutectic solvent presenting the ratio 1:4 between the two chemicals. The coatings produced are compared aswellwith their homologues obtained fromthe well characterized choline chloride/ethylene glycol system, showing equivalent quality
Electrodeposition of nickel from DES on aluminium for corrosion protection
No full textIn the present study, the possibility of nickel deposition from a deep eutectic solvent on a water-sensitive substrate like aluminium was investigated. The electrolyte used was based on a 1:2 molar mixture of choline chloride and urea with the addition of nickel chloride to provide nickel ions and ethylendiammine (ED) to complex. The deposition from the solution described having 1:2 as a Ni/ED molar ratio gave interesting results in terms of adhesion to aluminium and uniformity of the deposition. The electrochemical study of the solution is provided. Application of electrodeposited Watt’s nickel and electroless NiP was also attempted on the layers from ionic liquid. The morphological characterisation proved the quality of the layers, while a corrosion study demonstrated the protective properties of the coatings obtained
Inkjet assisted electroforming and collective actuation of disk-shaped magnetic micromotors
No full textISSN:2352-940
Electroless plating of PLA and PETG for 3D printed flexible substrates
Full text linkThe NiP and Cu electroless metallization of 3D printed polymers is
presented. The plating process is tested on suitable samples, which
reproduce the printing morphologies used in the 3d printing of
objects. An alkaline etching is used for both the polymers in order
to modify the surface properties and enhance the adhesion and
uniformity of the metallic coating. For the activation of the surface
a tin free process involving an immersion in palladium and
subsequent reduction to form metallic nuclei is employed. The Cu
and NiP bath are selected to operate in temperature ranges
comparable to the glass transition temperatures of the polymers.
Adherent and uniform layers of NiP (3-4 % P wt.) and Cu can be
easily obtained for esthetic and functional applications
A review of reverse pulse plating techniques in the electrodeposition of magnetic alloys – Part 1
Full text linkMagnetic materials always arouse interest due to their unique properties. Both soft and hard magnetic materials are exploited for energy harvesting application, magnetic recording and in MEMS. To boost the applicability of these materials, more versatile fabrication techniques must be developed. Even though the rare earth permanent magnets produced through powder metallurgy can guarantee the highest magnetic performance, this fabrication technique is not practical for the MEMS industry. Moreover, rare earths are very expensive elements. Electrodeposition seems a preferable alternative to chemical or physical vapour deposition techniques to produce both thin and thick magnetic deposits based on transition metal alloys. Among electrodeposition techniques, reverse pulse plating (RPP) guarantees improved mechanical properties and has been found to be beneficial for reducing internal stresses and modifying the internal microstructure and surface morphology as well as for producing thicker layers without observing cracks. Part 1 of the review focuses on how RPP can be used to tailor mechanical properties and morphology to achieve miniaturisation compared to other techniques, particularly in application fields that can benefit from it, such as the microelectronics industry. RPP also modifies magnetic properties by inducing changes in the microstructure. In Part 2 of this review, the state-of-the-art of hard and soft magnetic alloys deposited through RPP will be discussed, examining how this technique can tailor the crystalline structure to influence the coercivity of soft magnetic materials and the magnetic anisotropy of hard magnetic materials
- …
