Zeolite is a kind of aluminosilicate compound with cubic lattice. Molecular sieve has a uniform microporous structure, cavity diameter of its uniform, these holes can than the diameter of small molecules adsorbed to the internal cavity, and has the priority on the adsorption capacity of polar molecules and unsaturated molecules, which can make different degrees of saturation degree, different from different molecular size molecular separation and the boiling point of different, that is "sieving" molecules, called molecular sieve. Molecular sieves are widely used because of their high adsorption capacity, high thermal stability and other advantages of other adsorbents.
In the field of biological macromolecules, conventional Bio-Rad SEC molecular sieves are common.
By adjusting the temperature, American scientists have been able to precisely control the size of a hole in a titanium silicate material and produce a sophisticated new molecular sieve. Some have a large number of microporous crystalline material internal uniform, molecular size than small holes to pass through, while large molecules cannot pass through, so you can play the role of different molecular separation, this kind of material is called molecular sieve.
In fact, in 2001, scientists in the UK "science" magazine reported that they found a substance called ETS4 titanium silicate molecular sieve can be used as good. When the temperature rises, ETS4 will gradually decrease the size of micropores in the dehydration. With this method, the pore size can be finely adjusted in the range of 3 to 4 angstroms (1 is equal to one billionth of a meter). Scientists say that some common elements such as nitrogen, methane, oxygen, argon and water molecules in 3 dimensions to 4 or so, not much difference between each other size can effectively separate them, ETS 4 produced by molecular sieve. Researchers have tried to use ETS4 from the content of nitrogen and methane in the mixture of nitrogen decreased from 18% to 5%, and in the separation of argon and oxygen, nitrogen and oxygen in the experiment is successful. It is believed that this technology will have important commercial applications.