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Topic: Copper Colloidal Suspension  (Read 4006 times)

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Offline poe et tree

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Copper Colloidal Suspension
« on: December 31, 2007, 09:05:33 AM »
Hi.  I've been working on a project to find more modern and efficient ways to produce colloids for use in nanotechnology as well as medicine.  My main preoccupation has been with hydrogen peroxide and its varied reactions with certain metals and metal salts to produce more long lasting suspensions.  However, with recent experiments I found that a partially oxidized solution of copper particles in such a solution of hydrogen peroxide, will react with sodium bicarbonate to form a colorless solution.  I have been unable to fully grasp what is occurring here, and so I ask, if anyone may have insight on the matter, to please enlighten me as to what is happening.

Offline Borek

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Re: Copper Colloidal Suspension
« Reply #1 on: December 31, 2007, 09:17:24 AM »
What do you mean by "partially oxidized"? How much H2O2 in the solution? What pH of the solution?

Not that I have any ideas.
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Offline poe et tree

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Re: Copper Colloidal Suspension
« Reply #2 on: December 31, 2007, 10:00:46 AM »
The method I used to suspend the copper particles caused some to oxidize, as was evident by a minute quantity of settled material which subsided after being stirred thereafter.

I used a 3% solution of hydrogen peroxide, since it's readily available and contains a sufficient amount of ions to conduct the needed charge.

I'm sorry, but I did not consider the pH, and thus I didn't take any readings.

Offline IITian

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Re: Copper Colloidal Suspension
« Reply #3 on: December 31, 2007, 12:12:23 PM »
pH of the suspension is fairly important. It dictates the stability of a suspension. Moreover, the stability of the oxide formed (if any) will also depend on the pH.

Offline poe et tree

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Re: Copper Colloidal Suspension
« Reply #4 on: December 31, 2007, 05:40:15 PM »
Yes, I understand.  So I would like to retry the experiment again, this time with a series of readings.  For now I guess we can just leave it alone, but I would like to resume eventually in the near future.

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