phlogiston
International Hazard
Posts: 1378
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline
Mood: pyrophoric
|
|
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]
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer
|
|
weiming1998
National Hazard
Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline
Mood: Amphoteric
|
|
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.
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
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.
|
It's quicker with glycose syrup and even better is sodium fomate, acc. Fleaker.
|
|