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 Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

nachricht The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

Construction of practical quantum computers radically simplified

05.12.2016 | Information Technology

NASA's AIM observes early noctilucent ice clouds over Antarctica

05.12.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>