phlogiston
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preventing a smooth silver coating
I have a solution containing silver that I got from dissolving old X-ray film in a mixture of bleach and sodium hydroxide. To reduce the silver, I
suspended a copper sheet in the solution.
The sheet quickly gets covered with a beautifully smooth layer of silver. However, it apparently completely covers the copper since the reaction then
stops.
I know there are agents that can be added to electroplating baths that help to obtain a smooth coating (urea for instance). Does anyone know compounds
that are known to do the opposite, i.e. interfere with forming a smooth coating?
[Edited on 21-8-2012 by phlogiston]
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"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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weiming1998
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Quote: Originally posted by phlogiston  | I have a solution containing silver that I got from dissolving old X-ray film in a mixture of bleach and sodium hydroxide. To reduce the silver, I
suspended a copper sheet in the solution.
The sheet quickly gets covered with a beautifully smooth layer of silver. However, it apparently completely covers the copper since the reaction then
stops.
I know there are agents that can be added to electroplating baths that help to obtain a smooth coating (urea for instance). Does anyone know compounds
that are known to do the opposite, i.e. interfere with forming a smooth coating?
[Edited on 21-8-2012 by phlogiston] |
Instead of sticking copper in, reduce the Ag+ ions with a mixture of sugar and NaOH. I obtained almost pure silver powder from reducing AgCl with it.
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blogfast25
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| Quote: Originally posted by weiming1998 |
[Edited on 21-8-2012 by phlogiston][/rquote]
Instead of sticking copper in, reduce the Ag+ ions with a mixture of sugar and NaOH. I obtained almost pure silver powder from reducing AgCl with it.
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It's quicker with glycose syrup and even better is sodium fomate, acc. Fleaker.
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