Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mechanoluminescence event yields novel emissions, reactions

09.05.2007
Researchers at the University of Illinois report that a new study of mechanoluminescence revealed extensive atomic and molecular spectral emission not previously seen in a mechanoluminescence event. The findings, which appear online this month in the Journal of the American Chemical Society, also include the first report of gas phase chemical reactions resulting from a mechanoluminescence event.
Mechanoluminescence is light generated when a crystal, such as sugar or quartz, is fractured by grinding, cleaving or via other mechanical means. Sir Francis Bacon wrote about this phenomenon as early as 1605. Others have used the effect to impress, if not enlighten, others.

"You may, when in the dark frighten simple people only by chewing lumps of sugar, and, in the meantime, keeping your mouth open, which will appear to them as if full of fire," Father Giambattista Beccaria wrote in "A Treatise Upon Artificial Electricity," in 1753.

Scientists believe mechanoluminescence occurs as a result of the generation of opposite charges along the fracture plane of an asymmetrical or impure crystal. When the charges recombine the surrounding gas is ionized and emits light.

Mechanoluminescence that results from simple grinding or cleavage of a crystal can be quite weak and difficult to study. Late last year, U. of I. chemistry professor Kenneth Suslick and graduate student Nathan Eddingsaas reported in the journal Nature that a new technique, the sonication of crystal slurries, produced a much more intense mechanoluminescence than grinding. Sonication, the use of sound energy to agitate particles or other substances, causes high intensity collisions of crystal particles in liquid slurries.

The resulting mechanoluminescence is an order of magnitude brighter than that produced by grinding.

Sonication of liquids causes acoustic cavitation: the formation, growth and implosion of bubbles. This generates tremendous heat, pressure and shockwaves within the liquid that can exceed the speed of sound. Crystal particles suspended in a sonicated liquid collide and fracture, causing intense mechanoluminescence.

The new study involved the sonication of a slurry of recorcinol
(sugar) crystals in the liquid paraffin, dodecane. When nitrogen or oxygen was bubbled through the sonicated slurry, the resulting emission spectrum was more than a thousand time more intense than that produced by grinding. The researchers also saw emission lines not previously reported in a mechanoluminescence event. These peaks on the mechanoluminescence spectra are evidence of gas phase chemical reactions during the event.

"When oxygen is present, chemical reactions take place that are similar to those that occur in the production of diamond films using an electrical discharge," Suslick said. "The intense mechanoluminescence and chemical reactions produced by ultrasound give us a better understanding of mechanoluminescence, mechanochemistry and the effect of ultrasound on solids within a liquid."

Editor's note: To reach Kenneth Suslick, call 217-333-2794; e-mail:
ksuslick@uiuc.edu.

News Bureau | University of Illinois
Further information:
http://www.news.uiuc.edu/news/07/0508sonication.html

Further reports about: Emission chemical reaction mechanoluminescence produced

More articles from Life Sciences:

nachricht Closing in on advanced prostate cancer
13.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Visualizing single molecules in whole cells with a new spin
13.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>