Silver spray

Fig. 1. Lacquer-coated optical readout laser disk master. Plating by (a) electroless silver spray coating and by (b) vacuum evaporation. Scale bar, cm.

Surfaces. Essentially any electrically conductive surface can be electroplated, although special techniques may be required to make the surface electrically conductive. Many techniques ate used to metalline nonconductive surfaces. These are weU-covered ia the Hterature (3) and can range from coating with metallic-loaded paints or reduced-silver spray, to autocatalytic processes on tin—palladium activated surfaces or vapor-deposited metals. Preparation steps must be optimized and closely controlled for each substrate being electroplated. 

Inhalant is a term applied to an estimated 1,000 to 1,400 legal products used in households, industry, businesses, and medical settings. These products are as common as a felt-tip marker, a bottle of correction fluid or nail polish remover, a tank of gasoline, a tube of model airplane glue, air freshener or vegetable cooking spray, or a can of silver spray paint. 

Over 1,000 products are abused as inhalants. Users may initially choose an inhalant because of its availability, but most indicate individual preferences for certain chemicals. Sniffers will often choose a specific product to abuse, be it a brand of glue, correction fluid, gold or silver spray paint, or whippets. In some regional areas toluene is the most popular inhalant in others, gasoline and Freon. 

Gold and silver spray paints are preferred by some users for the solvents that keep the metallic particles suspended in the spray. 

Silver-spray process sinter coating Solution coating... 

Silver-spray process n. A metallizing process based on glass-mirror art. The plastic article is first cleaned and lacquered as in vacuum metallizing, then the lacquer is sensitized in an oxidizing aqueous solution of sulfuric acid and potassium dichromate. A silver-forming solution, e.g., silver nitrate and an aldehyde, is sprayed on the article with a two-nozzle spray gun so that the components mix at the surface. After rinsing and drying a final topcoat of lacquer is applied over the silver. 

Fig. 8.18 (a) Anodic stripping voltaimnograms for the oxidation of silver nanoparticles contained in a commercially available colloidal silver spray cleaning product that had become adhered to a screen-printed carbon electrode in authentic seawater media after 0 min (black line), 15 min (green line), 30 min (pink line), 45 min (blue line) and 60 min (red line), (b) A plot of the stripping charge for the silver nanoparticle stripping peaks vs. time. Reproduced from reference (74)... 

Hydantoin itself can be detected ia small concentrations ia the presence of other NH-containing compounds by paper chromatography followed by detection with a mercury acetate—diphenylcarba2one spray reagent. A variety of analytical reactions has been developed for 5,5-disubstituted hydantoias, due to their medicinal iaterest. These reactions are best exemplified by reference to the assays used for 5,5-diphenylhydantoiQ (73—78), most of which are based on their cycHc ureide stmcture. Identity tests iaclude the foUowiag (/) the Zwikker reaction, consisting of the formation of a colored complex on treatment with cobalt(II) salts ia the presence of an amine (2) formation of colored copper complexes and (3) precipitation on addition of silver(I) species, due to formation of iasoluble salts at N. ... 

This conversion is normally accompHshed by immersion, but spraying, swabbing, bmshing, and electrolytic methods are also employed (178) (see Metal SURFACE treatments). The metals that benefit from chromium surface conversion are aluminum, cadmium, copper, magnesium, silver, and 2inc. Zinc is the largest consumer of chromium conversion baths, and more formulations are developed for 2inc than for any other metal. 

Note Rhodamine B is a universal reagent that can be used on silica gel, talc, starch [5] and cellulose layers, just as on urea [1] or silver nitrate-impregnated [7] phases. Liquid paraffin-impregnated silica gel and RP layers are less suitable, since the background to the chromatographic zones is also intensely colored. It is often possible to increase the detection sensitivity by placing the plate in an atmosphere of ammonia after it has been sprayed or dipped, alternatively it can be oversprayed with sodium or potassium hydroxide solution. 

Thermal conductivity can be as low as one-eighth that of solid metal in the case of steel 7 W/m°C. The electrical resistance (specific) of copper, zinc and silver is about twice that of the cast metal, and of aluminium as much as five times, depending on spraying conditions. Adhesion in tension should... 

Silver Highly conductive (0.1 ohm per square foot or less) applied by conventional spray equipment easy application electrically stable (minimal change in resistance with environmental cycling) easily applied to selected area field repairable. High cost... 

Armstrong, B., 1977, Chemical spray silvering, Appl. Optics 16, 2785 Burge, J. H., Anderson, D. S., 1994, Full-aperture interferometric test of convex secondary mirrors using holographic test plates, SPIE 2199, 181 U.S. Patent 5,737,079. 

Reagent 2 Spray solution 2 Ammoniacal silver nitrate solution (precise composi-... 

Spray solution Dissolve 1 g potassium peroxodisulfate and 17-34 mg silver nitrate in a mixture of 1 ml acetone and 99 ml water [1,2] or in pure water [3]. 

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