Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Photochemistry research could lead to cleaner environment, new sensors

21.11.2003


Alistair Lees spends much of his research time hoping to see the light.




Using tools that improve by several orders of magnitude on the accuracy of microscopes and stopwatches, Lees is working at the molecular level to explore the effect of light on chemical systems. The field is called photochemistry and Lees’ efforts could help to find less-expensive ways to produce gasoline, make the environment cleaner and safer, and enhance the quality of microcircuitry and the equipment that relies on it.

While most chemists work with molecules in their ground or normal states, Lees has spent the past two decades working with "excited" molecules, a state attained when molecules absorb light, known as second chemistry.


The reactions that occur during these excited states are incredibly fast - typically about one tenth of one quadrillionth of a second. To be studied, they must be slowed or in some other way inhibited and Lees has developed a unique approach.

Excited state molecules generally emit light, give off heat or break into fragments as they return to the ground state. Relying on this, many chemists - like forensic experts who determine the nature of an explosion by studying resulting debris - use a technique called matrix isolation to study the fragments produced immediately after a molecule emits light.

Lees has instead synthesized entire new molecules, which do not fragment in their excited states. When cooled, his creations remain intact and display luminescence, giving him an unprecedented chance to study the second chemistry involved - an approach, which has opened the door to the development of several promising applications.

Working with $1.2 million in grants from the U.S. Department of Energy and the American Chemical Society, Lees is studying hydrocarbon activation, particularly how some new rhodium and iridium chemical compounds act as catalysts to break apart the bonds of methane.

The reaction suggests the possibility that the small methane molecule could be built up to the size of the larger oil molecule. Methane, or natural gas, usually does not react with other compounds, but because it is both abundant and recyclable, it is an attractive alternative to oil.

Lees’ preliminary research indicates it might someday be able to replace oil in the production of many fuels, as well as a host of other products, including plastics and pharmaceuticals.

Lees’ research is also likely to help manufacturers of a wide range of products. Supported by a grant from IBM, Lees is incorporating some of his light-emitting molecules into adhesive polymers. As the adhesive sets, its luminescence changes from red to orange to yellow, signaling appropriate curing and an optimal bond.

The microelectronics industry is interested in this research. If adhesives aren’t completely set during the assembly process, machines fail, parts break and production costs soar. The aerospace and automobile industries are also interested, Lees said. "Clearly, it’s important, when you’re riding in a car or a plane that it not fall apart," he said Photoinitiators is another application of Lees’ work. "We found that some of our organometallic compounds actually initiate polymerizations reactions when exposed to light," he said. Lees is collaborating with General Electric and IBM to research how this technique could be used to enhance microcircuitry production.

Another application of Lees’ work is likely to stem from the arena known as supramolecular chemistry. Lees is finding ways to insert luminescent compounds into the cavities of some large molecules. Because the luminescence of such molecules changes substantially in reaction to their environment, they make excellent sensors.

Recently, Lees and his team found a compound that is a good sensor for cyanide. Others, he said, are sensitive to hydrocarbon vapors, which may help detect pollutants, another important application in today’s industrial world.


Susan E. Barker | Binghamton University
Further information:
http://research.binghamton.edu/discovere/november2003/TopStories/Lees.htm

More articles from Power and Electrical Engineering:

nachricht Cooling buildings with solar heat
26.09.2016 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

nachricht Philippines’ microsatellite captures best-in-class high-resolution images
22.09.2016 | Hokkaido University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Stronger turbine blades with molybdenum silicides

26.09.2016 | Materials Sciences

Scientists Find Twisting 3-D Raceway for Electrons in Nanoscale Crystal Slices

26.09.2016 | Materials Sciences

Lowering the Heat Makes New Materials Possible While Saving Energy

26.09.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>