Featured Research

from universities, journals, and other organizations

Mechanoluminescence Event Yields Novel Emissions, Reactions

Date:
May 9, 2007
Source:
University of Illinois at Urbana-Champaign
Summary:
A new study of mechanoluminescence revealed extensive atomic and molecular spectral emission not previously seen in 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.

The phenomenon of mechanoluminescence was first discovered in 1605 by Sir Frances Bacon from scratching sugar with a knife. The top image is a photograph of the mechanoluminescence of N-acetylanthranilic acid crystals crushed between two transparent windows.
Credit: N. C. Eddingsaas & K. S. Suslick

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.”


Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University of Illinois at Urbana-Champaign. "Mechanoluminescence Event Yields Novel Emissions, Reactions." ScienceDaily. ScienceDaily, 9 May 2007. <www.sciencedaily.com/releases/2007/05/070508190022.htm>.
University of Illinois at Urbana-Champaign. (2007, May 9). Mechanoluminescence Event Yields Novel Emissions, Reactions. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2007/05/070508190022.htm
University of Illinois at Urbana-Champaign. "Mechanoluminescence Event Yields Novel Emissions, Reactions." ScienceDaily. www.sciencedaily.com/releases/2007/05/070508190022.htm (accessed September 18, 2014).

Share This



More Matter & Energy News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Stocks Hit All-Time High as Fed Holds Steady

Stocks Hit All-Time High as Fed Holds Steady

AP (Sep. 17, 2014) The Federal Reserve signaled Wednesday that it plans to keep a key interest rate at a record low because a broad range of U.S. economic measures remain subpar. Stocks hit an all-time high on the news. (Sept. 17) Video provided by AP
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

Newsy (Sep. 16, 2014) MIT developed a robot modeled after a cheetah. It can run up to speeds of 10 mph, though researchers estimate it will eventually reach 30 mph. Video provided by Newsy
Powered by NewsLook.com
Manufacturer Prints 3-D Car In Record Time

Manufacturer Prints 3-D Car In Record Time

Newsy (Sep. 15, 2014) Automobile manufacturer Local Motors created a drivable electric car using a 3-D printer. Printing the body only took 44 hours. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins