Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemists grow crystals with a twist -- and untwist

19.07.2010
Chemists from New York University and Russia's St. Petersburg State University have created crystals that can twist and untwist, pointing to a much more varied process of crystal growth than previously thought.

Their work, which appears in the latest issue of the Journal of the American Chemical Society, may explain some of the properties of high-polymers, which are used in clothing and liquid crystal displays, among other consumer products.

Crystal growth has traditionally been viewed as a collection of individual atoms, molecules, or small clusters adding to a larger block that remains in a fixed translational relationship to the rest.

But the NYU and St. Petersburg State University chemists discovered a wholly new phenomenon for growth— a crystal that continually changes its shape as it grows.

To do this, the researchers focused on crystals from hippuric acid—a derivative of the amino acid glycine. As molecules were added to the end of fine crystalline needles, stresses built up at the tips of the crystals and resulted in a helical twist—much like DNA's double helix. The process was reversed when crystals thickened from the opposite end of the growing tip—that is, the crystals stiffened, thereby undoing the twisted formations. This is because the elasticity of the crystals decreases as they become thicker, thus "squeezing out" the deformations that were induced at the growing tip.

"This competition between twisting and untwisting creates needles with a rainbow of colors, which is a characteristic of tightly wound helices, as well as ribbons that have become completely untwisted," said Bart Kahr, one of the study's co-authors and a professor in NYU's Department of Chemistry, explaining the crystals' appearance. "This is a very strange and new perspective on crystal growth."

"This dynamic has not been observed before and points to a much more active process of crystal growth than we had anticipated," added Kahr, also part of NYU's Molecular Design Institute.

The work's other co-authors were Alexander Shtukenberg, a senior researcher from Russia's St. Petersburg State University and a visiting scholar at NYU, and John Freudenthal, an NYU doctoral student.

James Devitt | EurekAlert!
Further information:
http://www.nyu.edu

More articles from Life Sciences:

nachricht Individual Receptors Caught at Work
19.10.2017 | Julius-Maximilians-Universität Würzburg

nachricht Rapid environmental change makes species more vulnerable to extinction
19.10.2017 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>