The working principle of the glove box is that the working gas inside the glove box is circulated in a closed manner through pipelines, circulating fans, etc. between the glove box body and the purification column under the control and monitoring of PLC. The working gas circulates through the purification column and then returns to the glove box. As the circulation time passes, the water and oxygen content in the working gas inside the glove box will gradually decrease, eventually reaching the target of less than 1ppm.
Purification columns are generally filled with molecular sieves and copper catalysts, which have strong adsorption capabilities and can absorb and remove moisture and oxygen from glove boxes. When the gas inside the glove box passes through these purification materials, water and oxygen molecules are captured by the adsorbent, thereby maintaining a dry and oxygen free environment inside the glove box.
Do you know what materials can be used to adsorb oxygen in glove boxes?
Copper catalyst
Copper catalyst is an efficient deoxygenation material that can react chemically with oxygen at lower temperatures to produce copper oxide, thereby removing oxygen from the gas inside the glove box. Copper catalysts have regenerative properties and can restore their deoxygenation ability through reaction with hydrogen gas.
Activated carbon
Activated carbon is a carbon material with a highly developed pore structure. Its pores include micropores, mesopores, and macropores, and this porous structure gives it a large specific surface area, which can effectively adsorb oxygen. The adsorption of oxygen by activated carbon is mainly based on the principle of physical adsorption, which adsorbs oxygen molecules on its surface and pores through van der Waals forces between molecules.
The advantages are relatively low cost, easy access, and adsorption capacity for various gases. However, its adsorption selectivity is not as good as molecular sieves. While adsorbing oxygen, it also adsorbs a large amount of other gases such as carbon dioxide and water vapor. Therefore, in some glove box application scenarios that require precise gas composition, it may be necessary to use it in conjunction with other adsorbents.
calcium oxide
Calcium oxide can undergo chemical reactions with oxygen, thereby playing a role in deoxygenation. The main principle of its reaction is that calcium oxide can react with oxygen under certain conditions to form calcium oxide. However, this reaction is relatively complex, and in practical glove box applications, calcium oxide may also react with other components such as water vapor, so the overall environment inside the glove box needs to be considered when using it.
Its advantage is that it can serve as a chemical adsorbent, effectively removing oxygen under specific conditions, and is relatively inexpensive. However, due to its active chemical properties, it may have an impact on other components in the environment and should be used with caution.
It should be noted that the choice of adsorbent depends on the specific application requirements, usage environment, and cost considerations of the glove box. At the same time, the adsorption capacity of the adsorbent will gradually decrease with increasing use time, so it needs to be replaced or regenerated regularly to ensure that the anaerobic or low oxygen environment inside the glove box is maintained.
In addition, the anaerobic environment in the glove box not only relies on adsorbents, but also requires other measures such as material selection of glove box gloves, design and operation of gas purification systems, etc. Only by considering these factors comprehensively can we ensure that the anaerobic or low oxygen environment inside the glove box achieves the expected effect.
