Definition of molecular sieve in US English:

molecular sieve


  • A crystalline substance (especially a zeolite) with pores of molecular dimensions which permit the passage of molecules below a certain size.

    • ‘Since DNA molecules have much higher molecular weights than proteins, the molecular sieve used in electrophoresis of DNA must be different as well.’
    • ‘Butylated hydroxytoluene was added to the reaction mixture to prevent oxidation, and molecular sieves were added to keep the solvent dry.’
    • ‘Various jelly-like substances can act as molecular sieves.’
    • ‘Zeolite molecular sieves can also segregate molecules of the same size but different electrical characteristics.’
    • ‘They have anchored bimetallic catalysts to the insides of such molecular sieves and have found that they can selectively hydrogenate cyclic polyenes.’