Levitating droplets allow scientists to perform 'touchless' chemical reactions

Levitation has long been a staple of magic tricks and movies. But in the lab, it's no trick. Scientists can levitate droplets of liquid, though mixing them and observing the reactions has been challenging. The pay-off, however, could be big as it would allow researchers to conduct contact-free experiments without containers or handling that might affect the outcome. Now, a team reporting in ACS' Analytical Chemistry has developed a method to do just that.

Scientists have made devices to levitate small objects, but most methods require the object to have certain physical properties, such as electric charge or magnetism. In contrast, acoustic levitation, which uses sound waves to suspend an object in a gas, doesn't rely on such properties.

Yet existing devices for acoustic levitation and mixing of single particles or droplets are complex, and it is difficult to obtain measurements from them as a chemical reaction is happening. Stephen Brotton and Ralf Kaiser wanted to develop a versatile technique for the contactless control of two chemically distinct droplets, with a set of probes to follow the reaction as the droplets merge.

The team made an acoustic levitator and suspended two droplets in it, one above the other. Then, they made the upper droplet oscillate by varying the amplitude of the sound wave. The oscillating upper droplet merged with the lower droplet, and the resulting chemical reaction was monitored with infrared, Raman and ultraviolet-visible spectroscopies.

The researchers tested the technique by combining different droplets. In one experiment, for example, they merged an ionic liquid with nitric acid, causing a tiny explosion. The new levitation method could help scientists study many different types of chemical reactions in areas such as material sciences, medicinal chemistry and planetary science, the researchers say.

Research paper

Related Links
American Chemical Society
Space Technology News - Applications and Research

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Synthetic materials mimic living creatures
Evanston IL (SPX) Jun 23, 2020
Northwestern University researchers have developed a family of soft materials that imitates living creatures. When hit with light, the film-thin materials come alive - bending, rotating and even crawling on surfaces. Called "robotic soft matter by the Northwestern team," the materials move without complex hardware, hydraulics or electricity. The researchers believe the lifelike materials could carry out many tasks, with potential applications in energy, environmental remediation and advanced ... read more