ScienceDaily (Sep. 25, 2006) — The National Institute of Standards and Technology (NIST) has issued three new reference materials to support researchers studying the properties of commercially important zeolites.

First described in the 18th century, zeolites have seen increasing use in industry and commerce from cat litter to industrial catalysts and "molecular sieves." Zeolites belong to class of materials called alumino-silicates whose crystal structures form highly porous, nanoscale "cages" that can filter and trap small molecules. Naturally occurring zeolites are mined and widely used as absorbents in products such as cat litter. Tailored synthetic zeolites have a wide variety of more specialized applications, such as in laundry detergents (where they replace pollution-causing phosphates), and as catalysts in oil refineries. Because they can be designed with pores that pass only molecules of a certain size and shape, zeolites have excited considerable interest as molecular sieves for chemical separations--they are used in oxygen generation systems for medical oxygen, for example.

It is often extremely difficult to make precision measurements of key chemical characteristics for zeolites because they are ferociously hygroscopic. Humidity must be precisely controlled--and specified--to make meaningful measurements of the elemental content, for example. This has made it difficult to compare experimental results between different labs.

To provide a common basis for research on three widely used industrial zeolites, NIST has issued reference materials for Zeolite Y (RM 8850), Zeolite A (RM 8851) and Ammonium ZSM-5 Zeolite (RM 8852). While these materials do not come with the certified property values and uncertainty estimates furnished with NIST Standard Reference Materials (SRMs), these RMs do provide a common source of zeolite materials for measurement comparisons. Reference and information values are provided for major and trace element content, key atomic ratios, enthalpy of formation, unit cell parameters and particle size distributions.

For technical details, see https://srmors.nist.gov/tables/view_table.cfm?table=106-7.htm.

Story Source:

Adapted from materials provided by National Institute of Standards and Technology.

Zeolite Y, here magnified with dark field scanning transmission electron microscopy, is used to increase the yields in petroleum refinery catalytic cracking units. Scale of the image is approximately 7 micrometers across. (Image courtesy of National Institute of Standards and Technology)

Related Stories

Researchers Hunt For New Zeolites (Nov. 10, 2009) — In all the world, there are about 200 types of zeolite, a compound of silicon, aluminum and oxygen that gives civilization such things as laundry detergent, kitty litter and gasoline. But thanks to ...  > read more

Growing Catalysts: Research Sheds New Light On How Zeolites Organize Themselves (Dec. 12, 2006) — Porous materials are involved in many chemical reactions that affect our daily lives. Despite their wide use, there is little knowledge about them. An international team of researchers have just shed ...  > read more

New Whiter-Than-White Technology For Laundry Detergents (Sep. 5, 2006) — Laundry detergents that give new meaning to that old advertising cliché, "whiter than white," may emerge from a controlled-release technology scheduled to be described in the Aug. 22 issue of ...  > read more

Crystal Sieves, Born Anew: Hard Data Resolves Decades-Old Mystery Of How Certain Zeolites Form (Apr. 18, 2006) — The porous, sieve-like minerals known as zeolites have been used for decades in purifiers, filters and other devices. Yet creating and refining a new type of zeolite is still a matter of ...  > read more

Search ScienceDaily

Cars of the Future: Plastic Makes Perfect?