Dilute nitric or nitrous acid solution containing halide ions as effective media for pure gold dissolution

2015 ◽  
Vol 17 (30) ◽  
pp. 19948-19956 ◽  
Author(s):  
Masashi Hojo ◽  
Masahiko Yamamoto ◽  
Kei Okamura
Keyword(s):  
Acid Solution ◽  
Nitrous Acid ◽  
Gold Wire ◽  
Pure Gold ◽  
Halide Ions ◽  
Gold Dissolution ◽  
Effective Media ◽  
Dissolution Rate Constant ◽  
Chloride Salts ◽  
Aqueous Nitric Acid

Bromide salts are more effective than chloride salts in gaining the ability of dissolving gold in dilute aqueous nitric acid solution. At 60 °C, a piece of gold-wire (ca. 20 mg) is dissolved in 20 mL of as low as 0.10 mol L−1 HNO3 solution containing 1.0–5.0 mol L−1 NaBr and the dissolution rate constant, log(k/s−1), increases linearly with increasing NaBr concentration.

Pure gold dissolution in dilute chloric, bromic or iodic acid solution containing abundant halide ions

2017 ◽  
Vol 227 ◽  
pp. 295-302 ◽  
Author(s):  
Masashi Hojo ◽  
Masahiko Yamamoto ◽  
Tetsuya Maeda ◽  
Hiroki Kawano ◽  
Kei Okamura
Keyword(s):  
Acid Solution ◽  
Pure Gold ◽  
Halide Ions ◽  
Gold Dissolution ◽  
Iodic Acid

THE CHEMISTRY OF ETHYLENE OXIDE: V. THE REACTION OF ETHYLENE OXIDE WITH HALIDE IONS IN NEUTRAL AND ACID SOLUTION

1952 ◽  
Vol 30 (3) ◽  
pp. 169-176 ◽  
Author(s):  
A. M. Eastham ◽  
G. A. Latremouille
Keyword(s):  
Aqueous Solution ◽  
Ethylene Oxide ◽  
Acid Solution ◽  
Activation Energies ◽  
Hydrogen Halide ◽  
Halide Ions ◽  
Neutral Aqueous Solution ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Hydrolysis Of

The rates of reaction of halide ions with ethylene oxide in neutral aqueous solution and the rate of hydrolysis of ethylene oxide in acid solution have been measured and the activation energies determined. From these data and from the ratio of glycol to chlorohydrin formed when ethylene oxide reacts with excess aqueous hydrogen halide, the rates of the acid-catalyzed addition of halide ions to ethylene oxide at 25 °C. have been estimated.

Chemical selective coating of nickel / palladium / gold metallization on screen-printed thick film on LTCC and Al2O3 ceramic for high temperature applications

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000334-000338
Author(s):  
Jens Müller ◽  
Thomas Mache ◽  
Torsten Thelemann
Keyword(s):  
High Temperature ◽  
Thick Film ◽  
Low Cost ◽  
Gold Wire ◽  
Wire Bonding ◽  
Pure Gold ◽  
Al2o3 Ceramic ◽  
Selective Coating ◽  
Silver Palladium ◽  
Silver Silver

Electroless plating on silver is a low cost alternative to printing of mixed metals or pure gold paste systems on LTCC. It overcomes the necessity to have material transitions from inner to outer layers or from conductor lines to wire bonding- or solder-pads. Since no commercial process and material set for silver thick film conductors has been available on the market a proprietary Ni/Pd/Au coating technology was developed for the use on silver inks for LTCC and Al2O3-ceramic as a base for both soldering and wire bonding. The work included the screening of different chemicals as well as several silver paste systems from two commercial vendors. Conductor adhesion, plating layer thicknesses, plating accuracy, (lead free) solderability and gold wire-bondability were assessed to optimize the process. Layers of about 5 microns Ni, (0.1 to 0.3) microns Pd and (0.05 to 0.15) microns Au were electrolessly deposited. The developed Ni-Pd-Au finish is an economical alternative with only about a quarter of the cost compared to the conventional use of silver, silver / palladium and gold compounds for ceramic substrates. This technology allows coating of the structures down to a fine pad size of 200×200 microns and a minimum line width of 100 microns, without reducing the adhesion mechanism between thick-film metallization and ceramic substrate. By covering of pure conductors with high temperature glass or dielectrics, further material saving is possible. Besides, the process offers also very good coating of structures in cavities.

scholarly journals A method of drawing extremely fine wires

1832 ◽  
Vol 1 ◽  
pp. 455-456 ◽  
Keyword(s):  
General Principle ◽  
Nitrous Acid ◽  
Gold Wire ◽  
Distilled Water ◽  
Common Mode ◽  
The Common

The author refers to Musschenbroek for an instance of a gold wire, recorded to have been drawn by an artist at Augsburg so fine, that one grain of it would have the length of 500 feet. It is not said how this was effected, and some doubt has been entertained of the possibility of it ; but the author of this paper shows how gold may be drawn to the same degree of fineness, and also that platina may be made with great facility much finer than is above described. The general principle of the method is the same for both. The metal intended to be drawn is first reduced, in the common mode, to a wire of about the of an inch in diameter; and it is then coated with silver, so as to form a rod of considerable thickness. The rod is then drawn, as usual, till it is reduced to a slender wire, and it is presumed that the gold or platina contained in it is reduced in the same proportion as the silver. By steeping for a few minutes, in nitrous acid the silver is then dissolved; hut the gold or platina remain unaffected, and require merely to be washed in distilled water in order to free them from any portion of the solution or other little impurities that may adhere during the solution.

scholarly journals AMINOACRIDINE DYES AND THE SECONDARY STRUCTURE OF DNA IN SITU

1971 ◽  
Vol 19 (12) ◽  
pp. 761-765 ◽  
Author(s):  
MANUEL DIAZ ◽  
JOSE HIERRO ◽  
GRACIELA DEMICHELI DE DIAZ
Keyword(s):  
Secondary Structure ◽  
Acid Solution ◽  
Nitrous Acid ◽  
Deoxyribonucleic Acid ◽  
New Method ◽  
Green Fluorescence ◽  
Double Stranded Dna

A new method is proposed to study the secondary structure of deoxyribonucleic acid (DNA) in situ in fixed chromatin. It is based on acriflavine staining and on differentiation with a nitrous acid solution of the fixed cytologic preparation. The presence of green fluorescence after this treatment is regarded as indicative of double stranded DNA. Experiments are described with DNA-acriflavine mixtures in solution, DNA-agar models and cytologic preparations submitted to different pretreatments. The feasibility and limitations of the method are discussed in the light of the results reported upon.

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