Table of Contents
Acid boiling
Diamond is incredibly chemically stable and inert, which allows us to clean dirt off the surface using dangerously strong chemicals. A three-acid mix is effective at cleaning off the surface.
Chemicals
- Sulfuric acid 98%
- Perchloric acid 70-72%
- Nitric acid 65%
- Acetone
Dangers
- Causes severe skin burns and eye damage.
- May cause fire or explosion; strong oxidiser.
- If the temperature is too high, toxic, brown nitrous gases are produced.
Before using chemicals, they are obliged to read the safety data sheets. see MSDS material safety data sheet
FAQ
Can I raise the temperature for better or faster cleaning?
Raising the temperature does increase the reaction speed, and should make it faster to clean a diamond. However, this effect is non-linear and difficult to predict. When the strong acids are boiled at too high a temperature they can produce highly toxic gases such as NOx.
In short, do not set the temperature above 130 degrees celsius for the heat block and 170 degrees celsius for the sand bath.
Step by step
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Mount condenser
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mount Teflon sleeve
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connect water tubings on condenser
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Place the diamond sample in the flask
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Safety equipment for strong acids
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Take sulfuric acid, nitric acid and perchloric acid from the safety cabinet
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Provide acids, 3 pipette tips 5 ml, pipette, beaker with wash water and flask on pulp, Check if the fume is on
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Pipet 3 ml of sulfuric acid into the flask, rinse the pipette tip in the beaker glass and repel, pipet 3 ml of perchloric acid into the flask and gently mix, rinse the pipette tip in the beaker glass and repel, pipette 3 ml of salic acid into the flask and gently mix, rinse the pipette tip in the beaker glass and repel
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Connect the flask free of stress to the condenser, ensure that the flask is in good contact with the heat block or the sand bath, Acid bottles (clean?) place in the safety cabinet, if necessary fill up
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Attach cut fuses
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Connect the appliance to the gas washing bottles
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Get the acid waste canister from the safety cabinet, add the rinse water to the acid waste canister, check that the acid residues are outside the canister and clean it, place the acid waste canister in the safety cabinet
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Clean the beaker and place in the dishwasher, Do not touch water taps with acid on the gloves.
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Place a filter paper with “acid cleaning”, your name, date and time nearby
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Turn on the water cooling and check the tightness
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Set the max. Temperature (heat block max 130°C, sand bath max 170°C) and activate the heating
Es dürfen keine giftigen, braune nitrose Gase entstehe. In diesem Fall ist die Temperatur zu reduzieren.
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Close the fume and wait for the apparatus to reach the final temperature
Check that no toxic, brown nitrous gases may be produced. In this case, reduce the temperature.
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Switch off the heating after the necessary cleaning time (2 - 24 h) and wait until the acid mixture has room temperature. Set everything up in the picture.
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Disassemble the condensor and clean it with water.
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Pour the acid mixture in the flask into a beaker containing at least 50 ml of water. Rinse the flask with water. Remove the diamond sample with tweezers. Rinse the diamond with ultrapure water until it is pH 7.
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Rinse the diamond sample with acetone and gently dry it over a filter paper. Place the diamond sample in a suitable transport vessel, e.g. Eppendorf reactor.
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Put the collected acidic washing water into the acid waste canister.
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Dry the cleaned cooler with acetone and compressed air and place it in the cabinet.
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Dispose of the collected organic solvent residues.
Reinige den gesamten Arbeitsbereich. Es darf nirgends Chemikalienreste geben.
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Replace the water in the gas wash bottle. Place all pre-cleaned glasses in the dishwasher.
Clean the entire working area. There must be no chemical residue anywhere.
