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Specialty Chemistry Forums => Citizen Chemist => Topic started by: Gigi on May 17, 2005, 09:04:48 PM

Title: a coating question
Post by: Gigi on May 17, 2005, 09:04:48 PM
i have to plan and design a lab on this hypothesis: Graphite conducts electricity. Leather does not. Use this information to design 'a chemical method' for coating a leather article with gold'

i know i have do elctroplating for the last part and that i have to coat the leather with graphite(since eletroplating is done best when the article is coated with an other metal) but i don't know how to coat the leather with graphite. *delete me* ???this lab is due thursday and we only got it today. :-\
Title: Re:a coating question
Post by: limpet chicken on May 17, 2005, 10:34:25 PM
You could perhaps use a reducing agent and a solution of an easily reduced gold salt.

Hydrazine hydrate is used in a reaction to prepare ultrathin mirror and resistant surfaces on the insides of glassware from washing with a metal salt solution and the hydrazine hydrate.

Alternatively, you could attempt using ascorbic acid, as it is somewhat of a decent reducing agent, it will reduce copper salts, and less reactive metals, in aqueous solution, to the finely devided metal, so I would not be surprised at all if you could adapt the process to produce a fine layer of metallic gold upon a nonconductive surface.
Title: Re:a coating question
Post by: Donaldson Tan on May 18, 2005, 12:55:02 AM
hmm.. vapour deposition of carbon (soot) on the belt?
Title: Re:a coating question
Post by: billnotgatez on May 18, 2005, 05:39:28 AM
I think we discussed this before
use the search engine on this site with the key word leather
Title: Re:a coating question
Post by: Gigi on May 18, 2005, 07:01:22 PM
i know but that thread didn't help. what i really need is a way to coat leather with graphite.
Title: Re:a coating question
Post by: Donaldson Tan on May 18, 2005, 09:59:03 PM
when u put a piece of white paper above a flame, it turns black because soot from the flame deposits on the paper. I am not sure if this method will work for the belt. you could try.

Title: Re:a coating question
Post by: constant thinker on May 19, 2005, 08:44:10 PM
Epoxy is a very nice glue. Crazy glue is also. I'm sure those will stick to leather and graphite. Glues are a chemical way of sticking graphite to leather. You just need to find a glue that'll attach itself to both the leather and whatever your using for electroplating.
Title: Re:a coating question
Post by: limpet chicken on May 20, 2005, 12:25:12 PM
What about, impregnating the glue with PbO2, to act as a conductive electrode for electroplating?
Title: Re:a coating question
Post by: Grumples on May 23, 2005, 08:21:16 PM
you could probably coat something in a very thin layer of gold without electrolysis, and therefore without needing graphite.  I know that you can do it for silver: just last week, I silver plated a bottle (a standard high school demonstration) by coating the inside with sugar water, then adding a solution of Ag(NH3)2+.  The silver complex ion takes an electron from the sugar, and becomes silver metal on the side of the bottle.  I don't know if the exact reagents would work for you, but I'd be very surprised if you couldn't do something similar (coat with an easily oxidized sobstance, add gold ion to precipitate metallic gold).