Potassium Permanganate , Sugar, Lye Electroplating Solution Onto Copper for Making Art.
by SHOE0007 in Workshop > Science
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Potassium Permanganate , Sugar, Lye Electroplating Solution Onto Copper for Making Art.
Did you know that if you combine cold Sugar and Potassium hydroxide to a weak solution of Potassium permanganate and stir well with a stir rod you can plate a green to light green plate Mn+6 ions from the Manganese ions with sugar (oxidizer) with lye onto copper?
A good stir rod is needed with stirring to make the KmnO4 convert into different oxidization states with the sugar and lye.
Here are some theories on the Mechanism behind the KmnO4 reacting with sugar and Lye.
https://chemistry.stackexchange.com/questions/1954...
With Lye and sugar, the Mn is in a +7 state and it gets reduced to +2 state by the sugar and the lye. When a base is added OH- ions and electricity it helps keep the state of the Mn near +6 to +5.
Warning: Lye is corrosive, Potassium Permangate is toxic, irritanting and a strong oxidizer. Never mix Potassium Permangate with Glycerol or other Oils. Combing Potassium Permangate with Hydrochloric acid makes Chlorine gas, Combing it with conc Sulfuric acid makes a Potentially explosive compound Mn2O7 which can burst into flames with Organic Materials.
Supplies
Chemicals:
Potassium Permanganate.
Sugar (White sugar)
Potassium or Sodium hydroxide.
Water.
Citric acid or Tartaric acid.
Supplies:
Copper pipes.
Hotplate and Magnetic stirrer.
1 L beaker.
0-15 volt, 0-2 amp power supply device.
wires for electroplating the materials.
Stir rod.
Preparing the Solution.
Lye, sugar, and Potassium permanganate are required.
Add to 200 ml of water 7 to 8 grams of sugar I used 7.77 g and 8 g of Lye (KOH). Add them to a beaker with 200 ml of water to a small bottle clearly labeled Lye Sugar water.
Add to 600 ml about 10 g of Potassium Permanganate. Note going over 15 g will result in a thick sludge of MnO2 which may interfere with plating methods.
Allow the cold solution to be poured into the beaker directly or add the cold 4 deg C solution to the Potassium Permanganate solution by a 50 ml separatory funnel above. This allows for stirring and constant dripping. If the mixture is not constant at first you may get no green plating but a slight black tinge on the copper.
This would count as a failure and new plating copper crimps or Pipes would be needed.
Electroplating Techniques.
Add 8 to 10 g of Potassium Permanganate to 600 ml of tap water. Then when the solution of Lye and sugar is cold at 4 deg C add it to the separatory funnel with a big funnel. Allow the mixture to stir and mix for at least 30 to 60 minutes. You should add 200 ml slowly and carefully preventing any spills on the hotplate.
The copper crimps or Pipes must be soaked partly by clamps above the beaker. This prevents Manganese dioxide from clumping onto the metal and allows for a more smooth plating experience. I recommend stirring should be on Medium even when electroplating.
The voltage should be around 5-6 volts and current 0.9 to 1 amp this is ideal for plating the KmnO4, sugar, and Lye onto the metal.
The solution must be done and mixed between 2-3 hrs or the plating solution will not work well.
Urethane Coating Methods and Waste.
It is important to coat the plates with urethane paint. It hardens onto the surface and prevents the metal coating from coming off. Add a few tablespoons under a Lid to prevent it from going everywhere.
Under the light, it gives pretty results and appears green to lime green in color.
Finally, you must deal with the waste property by adding citric or tartaric acid (Not Hydrochloric acid it will generate chlorine gas), and not other strong acids! About 10 g of Tartaric acid was added to shift the pH from 14 to 6.0!
Conclusions.
Potassium permanganate plating is tricky I did have some failures you must mix and drip in with a sep funnel the Lye and sugar very slowly while stirring and electroplating the KmnO4. However I got some beautiful results Out of it which is worth sharing.
Always handle the waste as Neurotoxic and dangerous for you and the environment.
Thanks for reading this Instructable.