The characteristics of molecular sieves

Characteristics of Molecular Sieves

Molecular sieves are artificial crystalline aluminosilicates. Depending on the size of the cavities inside their crystals, they can adsorb or repel the molecules of different substances, and thus are vividly called "molecular sieves". They are composed of AlO₄ and SiO₄ tetrahedrons. In the lattice of molecular sieves, metal cations play a role in balancing the excess negative charges in the AlO₄ tetrahedrons. Substances with a molecular diameter smaller than the diameter of the cavities in the molecular sieve crystals can enter the molecular sieve crystals and thus can be adsorbed; otherwise, they will be repelled. Molecular sieves also have a preferential adsorption order according to the polarity or polarizability of different substances. Generally, polar molecules are easily adsorbed. (Molecular Sieves Wholesale)

Molecular sieves have good thermal stability and can withstand a brief high temperature of 600°C - 700°C. Molecular sieves are insoluble in water but soluble in strong acids and strong alkalis. Therefore, they can be used in a medium with a pH value of 5 - 11 and can exchange other cations in a salt solution.

Molecular sieves have the following properties: they have reversible adsorption for water, gases, and liquids; they have the characteristic of cation exchange; the channels of molecular sieves have a very high internal surface area. For these reasons, molecular sieves are suitable for deep drying, selective adsorption, and catalysis. Compared with other adsorbents, molecular sieves have outstanding characteristics: a very high adsorption capacity; selective adsorption and separation; catalytic properties; and ion exchange properties.