Silver acetylide is a very dangerous, very sensitive, and very costly impact explosive. Silver acetylide (Ag2C2) is a hobbyists alternative to working with even more dangerous materials like Armstrong's mixture and fulminates. Caps, booby traps, and those little snap pops use extremely dangerous impact sensitive explosives. Hobbyists attempting to recreate or invent new impact sensitive devices like the ones listed above would be better off using Ag2C2 rather than other more sensitive mixtures. The process described in this howto is a safe and easy way to create silver acetylide without expensive lab glassware.
There are several ways to make silver acetylide. I find that the method outlined here is the most suitable for hobbyists because it uses easy to obtain materials and does not require complicated processes.
Silver acetylide is formed when acetylene is bubbled through a silver nitrate solution. Calcium carbide will donate the acetylene the following way: CaC2 + H2O --> C2H2 + CaO. 300 ccs of acetylene are produced from every gram of calcium carbide. When the acetylene is bubbled through the silver nitrate solution, the following reaction occurs: C2H2 + AgNO3 --> Ag2C2 + HNO3.
After the reaction is finished, we will filter the goop we've created and let dry.
If you have access to lab glassware, I recommend using it. If you don't have access to this glassware, use the following: A balloon, a straw, and a glass flask (a glass cup will work). You will need ethanol, distilled water, silver nitrate, calcium carbide, a razor blade, and a filter (a coffee filter will work, but lab grade membranes are better).
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First prepare the silver nitrate solution. It will need to be 3% AgNO3 mixed with distilled water. Be sure to wear gloves and protective clothing, silver nitrate stains everything it comes in contact with. Mix the AgNO3 and H2O in a flask until the crystals are completely dissolved. | |||
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Next pour the solution into your flask, leaving a lot of empty room so that it does not bubble over when you are bubbling the acetylene through it. | |||
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Insert the straw into the flask, the straw should touch the bottom of the flask, but still hang outside of the flask enough to comfortably attach the balloon. | |||
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Insert a few grams of calcium carbide into the balloon. Quickly pour water into the balloon and pinch it shut. The calcium carbide will react with the water creating acetylene and heat. The balloon will heat up; you can hold it under running water to cool it down if necessary. | |||
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Insert the straw into the balloon's orifice, and pinch the balloon so it is tight around the straw. bubble the acetylene through the solution. White junk will form in the solution. This is the silver acetylide. This reaction produces hydrogen and acetylene gas that must be properly vented. |
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Remove the straw from the container, shaking off any sediment that may be attached into the solution. Put your filter over a cup and decant the solution into the filter. | |||
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Rinse the material in the filter with the distilled water, and then with the ethanol. Dispose of the liquid that falls through the filter. | |||
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Allow the sediment to dry until all the moisture is gone, this should be done in a dark place because the silver acetylide is photoreactive. This will take a few days. Once the silver acetylide dries, it becomes VERY sensitive to impact and heat. It must now be treated with the utmost care and caution. | |||
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Very carefully cut the silver acetylide into a powder with the razorblade. The method is similar to how cocaine is separated in movies (slicing), but not how cocaine is separated in real life (crushing). It is much safer to perform this process when the crystals are still retaining a little moisture. | |||
Store the finished product in a containers containing a very small amount of the powder. These containers should be covered with padding (like a paper towel or opaque foam). I would recommend storing it outside in a safe dark place where it is in no danger of falling.
There are many applications for silver acetylide. One can make globe torpedoes or those little snap and pops. In fact, a wide variety of novelty impact explosives can be made with this substance. Silver acetylide, unlike many other pyrotechnic compositions, detonates freely in air. This property creates the possibility of using it in a wide variety of applications. A bit of adhesive and a grain of silver acetylide placed on the end of a pool cue might be funny. A very small amount of the powder sprinkled on the inside of an ashtray makes for a very funny practical joke which causes cigarettes to explode. One might even go one step further and insert a small grain (no larger than a grain of salt) into the end of a cigarette, causing a mild pop when it is lit, damaging the cigarette. Care should be taken not to use to much, or the previous gag could turn dangerous.
