Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Synthetic molecular sieve binds water better than zeolites

24.09.2002


Zeolites are an extremely important class of inorganic materials that can separate gases or liquids on the basis of molecular size and shape. The backbone of a billion-dollar-a-year industry, these molecular sieves are used in numerous applications, from the production of biodegradable detergents, to the removal of moisture from natural gas pipelines, to the catalytic cracking of heavy petroleum distillates into gasoline.



Now, chemist Kenneth S. Suslick and colleagues at the University of Illinois at Urbana-Champaign have created a new class of materials that are like zeolites in many ways. These new molecular solids are more than 50 percent empty space ­ space that can trap molecules of the right size and shape, including water. The scientists report their discovery in a paper that has been accepted for publication in the journal Nature Materials, and posted on its Web site www.nature.com/materials.

"This organic zeolite analogue binds water faster and more strongly than the best drying agents and has a higher capacity for storing water," said Suslick, a William H. and Janet Lycan Professor of Chemistry at Illinois. "The material also shows shape selectivity, permitting only a narrow range of molecules to enter."


A naturally occurring mineral consisting of aluminum and silicon, zeolites were discovered in the Middle Ages. At the time, the properties of a material were tested by heating it with a blowpipe. When this material was heated, boiling water was released. The name zeolite is derived from Greek words meaning "boiling stone."

The ability to make other kinds of molecular sieves has been a major goal in materials chemistry. That goal has been frustrated, however, because most solids are not porous to begin with, and the process of generating pores causes most materials to collapse.

To build robust nanoporous solids that are not based on silica and alumina, the researchers used much larger molecular building blocks called metalloporphyrins ­ doughnut-shaped molecules that bind metal atoms in the middle hole. Metalloporphyrins are closely related to hemoglobin (the red pigment in blood) and chlorophyll (the green pigment in plants).

By heating a mixture of a special porphyrin acid and cobalt chloride to 200 degrees Celsius, Suslick and his colleagues created a compound called PIZA-1 (Porphyrinic Illinois Zeolite Analogue #1).

"PIZA-1 demonstrated remarkable properties as a synthetic molecular sieve for removing water from common organic solvents," Suslick said. "In addition, because the metalloporphyrin has a metal in the middle that can be catalytically active, the potential exists to make shape-selective catalysts for specific purposes. Not only can we selectively absorb molecules into the solid, we can also make the trapped molecules undergo chemical reactions ­ such as the catalytic oxidation of fuels."

Catalytic reactions that would convert the hydrocarbons in gasoline into the chemicals that react to make polymers such as nylon are not yet possible to achieve, Suslick said. "But the ability to use fossil fuels as chemical feedstocks, rather than just burning them, is a technology that will become very important this century."

Collaborators on the project were graduate student Margaret Kosal (now at Chem Sensing), postdoctoral researcher Jun-Hong Chou (now at Dupont), and X-ray crystallographer Scott Wilson. The National Institutes of Health and the U.S. Department of Energy funded the work.

James E. Kloeppel | News Bureau, UIUC
Further information:
http://www.news.uiuc.edu/scitips/02/0923sieve.html

More articles from Life Sciences:

nachricht Molecular microscopy illuminates molecular motor motion
26.07.2017 | Penn State

nachricht New virus discovered in migratory bird in Rio Grande do Sul, Brazil
26.07.2017 | Fundação de Amparo à Pesquisa do Estado de São Paulo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>