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Gases are removed for various reasons. Chemists remove gases from solvents when the compounds they are working on are possibly air- or oxygen-sensitive (air-free technique), or when bubble formation at solid-liquid interfaces becomes a problem. The formation of gas bubbles when a liquid is frozen can also be undesirable, necessitating degassing ...
Air-free techniques refer to a range of manipulations in the chemistry laboratory for the handling of compounds that are air-sensitive.These techniques prevent the compounds from reacting with components of air, usually water and oxygen; less commonly carbon dioxide and nitrogen.
Liquid nitrogen's efficiency as a coolant is limited by the fact that it boils immediately on contact with a warmer object, enveloping the object in an insulating layer of nitrogen gas bubbles. This effect, known as the Leidenfrost effect , occurs when any liquid comes in contact with a surface which is significantly hotter than its boiling point.
The purge gas is inert, i.e. by definition [1] non-combustible, or more precisely, non-reactive. The most common purge gases commercially available in large quantities are nitrogen and carbon dioxide. Other inert gases, e.g. argon or helium may be used. Nitrogen and carbon dioxide are unsuitable purge gases in some applications, as these gases ...
Sparging introduces a gas that has little or no partial pressure of the gas(es) to be removed, and increases the area of the gas-liquid interface, which encourages some of the dissolved gas(es) to diffuse into the sparging gas before the sparging gas escapes from the liquid. Many sparging processes, such as solvent removal, use air as the ...
Similarly to the nucleophilic carbon center in the carbene, the lone pair on the aluminium center binds to the first azide equivalent. Nitrogen gas is liberated. With the second equivalent of azide, a five-member ring is formed. Aluminium (I) systems undergo reactions with azides in the same fashion as carbenes. [10]
Atomic layer deposition (ALD) is a thin-film deposition technique based on the sequential use of a gas-phase chemical process; it is a subclass of chemical vapour deposition. The majority of ALD reactions use two chemicals called precursors (also called "reactants"). These precursors react with the surface of a material one at a time in a ...
Moisture, sealants, lubricants, and adhesives are the most common sources, but even metals and glasses can release gases from cracks or impurities. The rate of outgassing increases at higher temperatures because the vapor pressure and rate of chemical reaction increases. For most solid materials, the method of manufacture and preparation can ...