New Trends in Decorative Coatings 2 $ ? 6 ?
ecorative coatings applied with D . . sputter ion plating processes have become a widely accepted application for vacuum technology. Although the deposition itself is only one important step among others, indusmal decorative applications require a reproducible and productive coating system. Leybold, as a system manufacturer, is featuring machines with a high level of up-time as well as an extraordinary sales service. In addition, such equipment is able to control all manufacturing steps including the choice of substrate material, the proper machining of it, the advisable heat treatment, the correct surface machining, the appropriate electroplating and the right precleaning. All these factors have an important influence, since a successful product does not depend solely on film properties. All system features required in the performance portfolio need to be fulfilled. In some circumstances, features required for a satisfactory coating can only be determined in extensive field tests.
Decorative properties and chemical composition of hard coatings
Transition metal compounds (nitrides, carbides, etc.) find increasing use as decorative coatings combining intensive colours, high wear resistance and good corrosion resistance. While golden TiN and dark-grey TiC are limited in their colour variation, the addition of a second metal or a second metalloid widens the spectrum of decorative colours, e.g. to dark blue with (Ti, Al)N. In the search for new colours, a number of nitrides of binary IVa metal-based alloys were deposited by reactive magnetron sputtering. The correlation between colour and stoichiometry was determined by surface analytical methods. Proper selection of the process parameters (target composition, N2 flow rate, etc.) results in coatings with different colours exceeding the conventional spectrum of decorative coatings.
Single step formation of biocompatible bimetallic alloy nanoparticles of gold and silver using isonicotinylhydrazide.
Manufacturing nanoparticles with controlled physicochemical properties using environment-friendly routes have potential to open new prospects for a variety of applications. Accordingly, several approaches have been established for manufacturing metal nanoparticles. Many of these approaches entail the use of hazardous chemicals and could be toxic to the environment, and cannot be used readily for biomedical applications. In the present work, we report a single step bio-friendly approach to formulate gold (Au), silver (Ag), and Au-Ag alloy nanoparticles with desired surface corona and composition using isonicotinylhydrazide (INH) as a reducing agent. INH also functioned as a stabilizing agent by enabling a surface corona around the nanoparticles. Remarkably, within a single step INH could also provide a handle in regulating the composition of Au and Ag in bimetallic systems without any additional chemical modification. The physicochemical and surface properties of the different nanoparticles thus obtained have been examined by analytical, spectroscopic and microscopic techniques. Cell cytotoxicity (release of lactate dehydrogenase), cell viability and intracellular reactive oxygen species (ROS) assays confirmed that the Au, Ag, and Au-Ag bimetallic nanoparticles prepared with INH are biocompatible. Finally, the presence of organic surface corona of INH on the nanoparticles was found to impart nanozyme activity and antimycobacterial sensitivity to the nanoparticles.