Nano-porous Crystals — the zeolites

To understand natural crystals, to duplicate them, and then to do better . . . the art of synthesis!

The stone that boils: an amazing crystal

In 1756, Cronstedt made an astonishing dicovery: while heating a sample of the mineral stilbite, it became covered in bubbles at around 150 °C, as if the stone were boiling. Hence the name given to this mineral: "zeolite", from the Greek zeo (to boil) and lithos (stone).

X-rays provide evidence of the nano-porous structure of this crystal

In 1930, Taylor and Pauling used X-ray diffraction to study the first zeolite crystals and revealed that, at an atomic level, these minerals are made up of a nano-porous matrix. Stilbite is a sodium calcium aluminium silicate that can hydrate or dehydrate in a reversible manner, according to the temperature. Water is trapped within the cavities of the structure.
There are around 50 natural zeolites and more than 500 articifial zeolites have now been synthesized . . .

By using the crystallographic approach scientists were able to "visualize" the different atomic arrangements and cavities, enabling them to understand and then create new zeolites.
Zeolites are widely used in industry for water purification, as catalysts, for the preparation of advanced materials and in nuclear reprocessing. They are used to extract nitrogen from air to increase oxygen content for both industrial and medical purposes. Their biggest use is in the production of laundry detergents. They are also used in medicine, in agriculture and in the oil industry.