Australian researchers have developed a new way to control chemical reactions that could be cleaner industry and cheaper nanotechnology.
Modern chemistry, and indeed life as we know it, would be unthinkable without catalysts that make targeted reactions possible.
The ultimate examples are nature's enzymes, which can vary reaction rates by 14 orders of magnitude and thus control vital processes in our cells.
In standard chemical reactions, catalysts are usually compounds that are added to a reaction mix to facilitate a reaction without becoming part of the product. But they are often expensive and can create unwanted by-products or contaminate the final products.
Desribed in a paper in Nature, a team of researchers associated with the ARC Centre of Excellence for Electromaterials Science (ACES) have shown that static electricity can be used to control chemical reactions.
The researchers from the Australian National University, the University of Wollongong and Universitat de Barcelona (Spain) used an electric field as a catalyst for a Diels-Alder reaction - a common reaction that is used to make a range of chemicals from self-healing materials to the drug cortisone.
Not only were they able to improve the reaction rate by a factor of five, but as electric fields can be turned on and off very quickly from outside the test-tube, the new approach provided them with a remote control over the chemical process.
While standard chemical reactions take place with molecules oriented in random directions in a gas or liquid, nature's enzymes work with carefully oriented charged functional groups, held in precise orientations, effectively generating an oriented field within the active site.
In a similar fashion, the researchers oriented all the substrate molecules in the same direction by attaching them to a surface. They then used the probe of the electron microscope to test each molecule as they applied an electric field of changing strength and polarity.
This enabled the team to vary the rate of the Diels-Alder reaction, in which a conjugated diene and a substituted diene form a cyclohexene system, by a factor of five.
According to lead researcher Professor Michelle Coote from the ANU, who had predicted that electric fields could strongly affect reaction rates, the result will help research understand a lot of natural biochemical reactions.