Nanoporous materials have crystallographically defined pores that fall within the nanometer size range. The best known family of nanoporous materials are the aluminosilicate zeolites, discovered in 1756 by the Swedish mineralogist and chemist Axel Cronstedt. Natural zeolites typically form inside aqueous inclusions within an igneous rock matrix, from mineral rich solutions at elevated temperatures. Hydrothermal synthesis methods mimic the conditions involved in the crystallization of zeolite minerals.
Synthetic zeolites exhibit unique adsorption, ion-exchange and catalytic properties.
Industrially, they are employed in gas separation, petrochemical production and wastewater treatment. This system is studied in our undergraduate Advanced Inorganic Laboratory, CHEM400B. Many synthetic zeolites , such as ZSM-5, are prepared in the presence of structure directing template species. These are typically quaternary alkylammonium compounds. Many frameworks have been prepared that have no naturally occurring analogue. In 1989, Bedard et al ., applied zeolite synthesis techniques to new compositional domains.