molecular sieve

American  

noun

Chemistry.

1. a compound with molecule-size pores, as some sodium aluminum silicates, that chemically locks molecules in them: used in purification and separation processes.

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molecular sieve British  

noun

1. chem a material that can absorb large amounts of certain compounds while not absorbing others and is thus suitable for use in separating mixtures

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Etymology

Origin of molecular sieve

First recorded in 1925–30