Printer Friendly

Serendipity yields buckyball trap for gases.

The word serendipity often pops up when scientists talk about buckyballs. In fact, chance has proven almost as important as planning in many recent experiments involving these soccerball-shaped, 60-carbon molecules of the fullerene family.

For example, chemist Douglas A. Loy at the Sandia National Laboratories in Albuquerque, N.M., says he and his co-workers were inspired to make the first buckyball polymer (SN: 12/14/91, p.391) only after Loy happened to catch a remark made at a conference.

Now a different group at Sandia reports another lucky bucky discovery. Chemist Roger A. Assink and colleagues were studying a pure, buckyball crystal with nuclear magnetic resonance (NMR) spectroscopy when they saw something odd: two lines in the spectrum. Since one spectral line normally indicates a pure buckyball crystal, two lines baffled Assink and his team at first. "We were quite concerned about what we really had," he says.

Later, however, the researchers found their sample wasn't pure after all. The extra line showed up in the crystal's spectrum because oxygen molecules had sneaked into gaps between the buckyballs in the crystal. Moreover, when Assink's team exposed another buckyball crystal to pressurized oxygen, they found that the crystal's NMR spectrum showed not one, but six lines, indicating that as many as six oxygen molecules had squeezed into the spaces around individual buckyballs. The group's findings will appear in an upcoming JOURNAL OF MATERIALS RESEARCH.

Interestingly, when the researchers exposed the buckyball crystal to gases other than oxygen, they discovered that the sample absorbed only certain ones. "Getting in and out of these crystals seems to depend on how big the gas molecule is," Assink says. For example, the sample could absorb molecular hydrogen but not methane, a much larger molecule.

A discriminating crystal could prove useful to industry, the scientists say. For instance, commercial natural gas, or methane, often contains impurities, such as nitrogen, which must be removed before the gas can be used as a fuel, Assink notes. A thin film containing buckyball crystals might act to filter out any contaminating gas, he adds.

Assink's group also found that soon after entering the crystal, the gas molecules begin to vacate it, although at a much slower pace. "If you put in a lot of oxygen, even after 25 days approximately half of the oxygen is left," Assink reports. The crystal's ability to release trapped gas over time might also lend itself to industrial applications, the researchers assert.

The scientists believe that manipulating either the buckyball molecule or its crystal geometry might also allow them to vary how many and what kinds of gas molecules a crystal will hold, as well as the release rate of those gases.

The Sandia team's findings have implications for future buckyball research as well, Assink says. Some supposedly pure buckyball crystals might actually contain enough gas molecules to throw an experiment off. "No matter how tight you pack the buckyballs, there are going to be vacancies --holes -- within the crystals," he notes.

Both Assink and Loy assert that for chemists and materials scientists, the buckyball bonanza is still going strong. "In the fullerene business, it's pretty much open season," Loy says. Moreover, "a lot of the serendipitous stuff that's been falling out may surprise the devil out of you."
COPYRIGHT 1992 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1992, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:chance occurrences
Author:Stroh, Michael
Publication:Science News
Date:May 30, 1992
Previous Article:Squeezing light for precision, speed.
Next Article:Cells melt mouse tumors.

Related Articles
Profile emerges of well-rounded molecule.
Buckyballs' supercool spring surprise.
Buckyball superconductors get warmer.
Hot times for buckyball superconductors.
Buckyballs still charm; scientists ponder the surprising properties of C60 and its siblings.
Sparking buckyball diamonds.
Atoms in buckyball cages.
In the lab, fullerenes gobble gases.
Fullerenes from space?
Buckyballs at bat: toxic nanomaterials get a tune-up.

Terms of use | Copyright © 2017 Farlex, Inc. | Feedback | For webmasters