Selective Electroless Copper Plating of Ink-Jet Printed Textiles Using a Copper-Silver Nanoparticle Catalyst

The electroless copper plating of textiles, which have been previously printed with a catalyst, is a promising method to selectively metallise them to produce high-reliability e-textiles, sensors and wearable electronics with wide-ranging applications in high-value sectors such as healthcare, sport, and the military. In this study, polyester textiles were ink-jet printed using differing numbers of printing cycles and printing directions with a functionalised copper–silver nanoparticle catalyst, followed by electroless copper plating. The catalyst was characterised using Transmission Electron Microscopy (TEM) and Ultraviolet/Visible (UV/Vis) spectroscopy. The electroless copper coatings were characterised by copper mass gain, visual appearance and electrical resistance in addition to their morphology and the plating coverage of the fibres using Scanning Electron Microscopy (SEM). Stiffness, laundering durability and colour fastness of the textiles were also analysed using a stiffness tester and Launder Ometer, respectively. The results indicated that in order to provide a metallised pattern with the desired conductivity, stiffness and laundering durability for e-textiles, the printing design, printing direction and the number of printing cycles of the catalyst should be carefully optimised considering the textile’s structure. Achieving a highly conductive complete copper coating, together with an almost identical and sufficiently low stiffness on both sides of the textile can be considered as useful indicators to judge the suitability of the process

The role of superimposing pulse bias voltage on DC bias on the macroparticle attachment and structure of TiAlN coatings produced with CA-PVD

Our attempts for cathodic arc physical vapor deposition (CA-PVD) of TiAlN coatings with high voltage pulse bias in order to tune their structural properties were not successful. Resulted coatings had an unacceptable rough surface with a large number of macroparticles (MPs). For solving this problem and benefiting from high voltage pulse bias-induced effects on the coatings structure we superimposed high voltage pulse on DC bias. For this purpose, Ti0.5Al0.5N coatings were deposited on HSS substrates using a DC bias voltage of 40 V and superimposed pulse bias voltages of 500, 1000 and 1500 V with a duty cycle of 14%. Structure, chemistry, morphology and mechanical properties of the coatings were determined in order to investigate the differences induced by the application of superimposed bias. Additionally, corrosion protection properties of the coatings were also investigated. According to the obtained results, this mode of application not only produced coatings with a denser and finer columnar structure but also resulted in a substantial reduction in the number of MPs. A decrease (maximum 3 at.%) in the Al content of the coatings was observed with increasing pulse bias magnitude when compared to their DC bias deposited counterpart. Substrate temperature also increased with increasing pulse bias magnitude, however, it did not increase above 460 °C. As a result of the decrease of MP attachment and denser structure of the coatings the corrosion protection properties of the coatings substantially improved. This effect became more pronounced with increasing superimposed voltage magnitude

Synthesis of W-Cu-Ag Nanopowders Produced by A Co-Precipitation Process

A homogeneous precipitation process was employed to prepare nanosized W-10%wtCu-10%wtAg powders using ammonium meta tungstate, copper nitrate and silver nitrate as precursors. The initial precipitates were obtained by reacting ammonium meta tungstate, copper nitrate and silver nitrate solutions under certain PH and temperature. In order to synthesis W-Cu-Ag composite powders, the initial precipitates washed, dried, and then calcined in air in order to prepare CuWO4-x, Ag2W4O13 and WO3 oxide powders for the next step reduction. The reduction was carried out in a hydrogen atmosphere to form the final W-Cu-Ag nanocomposite powders. The powders were characterized by X-ray diffraction (XRD) technique. The morphologies of the powders were observed by scanning electron microscopy (SEM).</jats:p

"Ni-B-based Polyalloy Electrocatalyst Coatings Deposited by MSPVD for Efficient Oxygen Evolution Reaction"

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