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 Perovskite-silicon solar cell research collaboration hits 25.2% efficiency
15.06.2018 | Helmholtz-Zentrum Berlin für Materialien und Energie GmbH

nachricht Second heat source optimises heat pump system
12.06.2018 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

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: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Carbon nanotube optics provide optical-based quantum cryptography and quantum computing

19.06.2018 | Physics and Astronomy

How to track and trace a protein: Nanosensors monitor intracellular deliveries

19.06.2018 | Life Sciences

New material for splitting water

19.06.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>