Solvent-Free Syntheses of Silver Products Produced Thereby
AssigneeCorning Incorporated
InventorsBenedict Yorke Johnson, Samuel Odei Owusu
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Abstract
Described herein are methods of making metallic or elemental silver in the solid state. These methods generally include a step of forming an at least substantially solvent-free solid state reaction mixture that includes a silver-containing compound and an organic acid, followed by heating the reaction mixture at a temperature and for a time effective to form metallic silver from a cationic silver species of the silver-containing compound. Also described herein are metallic or elemental silver produced by these methods.
Claims20
A method for making metallic silver, the method comprising:
- contacting a silver-containing compound with an organic acid to form an at least substantially solvent-free solid state reaction mixture, wherein a concentration of the organic acid is equimolar to or in a stoichiometric excess of a concentration of a cationic silver species in the silver-containing compound;
- and
- heating the at least substantially solvent-free solid state reaction mixture to a temperature less than a melting temperature of the organic acid for a time effective to produce a reaction product comprising metallic silver from the cationic silver species of the silver-containing compound.
The method of any of the preceding Claims, wherein the organic acid comprises lactic acid, citric acid, oxalic acid, ascorbic acid, fumaric acid, maleic acid, or a mixture thereof.
The method of any of the preceding Claims, wherein the contacting is performed in a presence of a catalyst, and the at least substantially solvent-free solid state reaction mixture comprises a catalytically effective amount of the catalyst.
The method of any of the preceding Claims, wherein the temperature of the heating is at least about 50 degrees Celsius.
The method of any of the preceding Claims, wherein the temperature of the heating is about 100 degrees Celsius to about 150 degrees Celsius.
The method of any of the preceding Claims, wherein the time of the heating is about 10 minutes to about 24 hours.
The method of any of the preceding Claims, wherein the time of the heating is about 15 minutes to about 5 hours.
The method of any of the preceding Claims, further comprising recovering the metallic silver from the reaction product.
The method of any of the preceding Claims, wherein the metallic silver is produced in a fractional yield of greater than 90 percent.
The metallic silver product of any of the preceding Claims, wherein the metallic silver product comprises an average particle size of less than or equal to about 1 micrometer.
A method for making metallic silver, the method comprising:
- contacting a silver-containing compound with an organic acid in a presence of a catalytically effective amount of a catalyst comprising an alkali metal-containing compound to form an at least substantially solvent-free solid state reaction mixture, wherein a concentration of the organic acid is equimolar to or in a stoichiometric excess of a concentration of a cationic silver species in the silver-containing compound;
- heating the at least substantially solvent-free solid state reaction mixture to a temperature less than a melting temperature of the organic acid for about 10 minutes to about 24 hours to produce a reaction product comprising metallic silver from the cationic silver species of the silver-containing compound;
- cooling the reaction product;
- disposing the cooled reaction product in a solvent, wherein the metallic silver is dispersed in the solvent and a remaining portion of the cooled reaction product is dissolved in the solvent;
- and
- separating the metallic silver from the solvent with the remaining portion of the reaction product dissolved therein.
Dependencies are inferred from the claim text.