How can I freeze liquid almost instantly?

Question

Let's say I have a plastic container full of liquid, and I want to freeze it instantly or very fast, How can I do this?
I've read that I can do this with nitrogen or CO2. Is this true? Are there laboratories the sell this?
Is this liquid poisonous once it's frozen in CO2 or Nitrogen?

Thanks.

Answer 1

Submerging the liquid in liquid nitrogen or putting it in a tank of dry ice would do it. It would not affect the item chemically, assuming it doesn't react with the nitrogen or CO2 (and, if it's stable in the atmosphere, that's not a problem).

If it's okay to lose some of the liquid by evaporation, you can place it in a near-total vacuum as well. That will force the liquid to evaporate and remove heat, causing it to freeze and boil simultaneously. For water, that happens at about 0.006 atmospheres.

Answer 2

Dry ice should do it. But you have to be careful with it. It can cause blisters when frozen if you don't use gloves and you don't want to breathe it in as it sublimates. Alton Brown used dry ice on his show to freeze berries very quickly. Its not instant but its much faster than your average freezer and probably easier to obtain that liquid nitrogen.