Are there any practical uses of liquid nitrogen?
We use liquid nitrogen on a regular basis in our laboratories, (other than freezing objects with water content or rubbers to their glass transition point and smashing them like a scene out of Terminator 2) Its especially good at trapping hot solvent vapors such that they don’t contaminate/damage lab equipment such as pump, manifolds etc. It is also used to degas (remove oxygen, nitrogen etc.) from solvents, this is knows as the freeze-pump-thaw technique. Its last and probably most important role in our department is to turn relatively insignificant materials into super conductors. These super conductors help power our NMR machines (Nuclear Magnetic Resonance) these are like an MRI at hospitals, however we put molecules inside, instead of whole organisms such as humans, to determine their structure. All made possible with liquid nitrogen! Forgot to mention, liquid nitrogen also used to cool detectors to improve their sensitivity in infrared spectrometers.
