NOV 07, 2017 6:00 AM PST

New Era of Isotope Separation: From Quantum Sieving To Supersonic Gas Beam

WRITTEN BY: Daniel Duan

The past October marked an exciting time for those in the field of isotopic science. Two brand new approaches to isolate and enrich light elements have been reported.

Isotopes are variants of a particular chemical element which differ in neutron number. For example, hydrogen (1H), deuterium (2H) and tritium (3H) are three isotopes of the same element. Isotope separation is a process of separating isotopes from one another or changing their relative abundances. The variance in a few neutrons can often create a vast difference in term of the usefulness of an isotope.

Although a variety of elements are purified for all kinds of purposes, nowadays the most common isotopes of interest are uranium for manufacturing nuclear fuel and several radioisotopes for medical treatments. The enrichment of silicon is also increasingly of interest in the electronics world, because pure silicon makes transistors of higher efficiency and improved thermal conductivity, and holds significant promise for quantum computing.

Several sophisticated techniques of physical separation have been developed over the years since the famous Manhattan project, mostly centering on the purification of uranium. Centrifugation was the first method invented to separate chemical isotopes by Jesse Beams of the University of Virginia to separate chlorine-35 from chlorine-37 in the 1930s. A decade later it became the most popular large-scale approach for uranium enrichment. The electromagnetic method uses a mass spectrometer, or spectrograph, to send a stream of charged elemental particles through a strong magnetic field and allow the separation of isotope by mass. In gaseous diffusion molecules of a lighter isotope would pass through a porous barrier, and become isolated from those of a heavier isotope.

The first publication was presented by an international team of researchers affiliated with South Korea’s Ulsan National Institute of Science and Technology (UNIST). They have developed a novel deuterium enrichment system based on a porous metal-organic framework (MOF) that employs quantum sieving effects.

Quantum sieving is a promising technique for isotope separations; heavier isotopes induce favorable adsorption in nanoscale pores in the MOF due to the difference in zero-point energy of isotopes. Deuterium plays a pivotal role in industrial and scientific applications (e.g., isotope tracing, neutron moderation, and neutron scattering), but its purification poses quite a challenge in modern separation technology.

The metal-organic framework developed by the Korean researchers. Credit: UNIST.

This breakthrough was featured on the cover of the Journal of the American Chemical Society in October. “Although the idea of separating deuterium using quantum sieving effects already exists, this work is not only the first attempt to implement two quantum sieving effects, KQS and CAQS, in one system, but also provides experimental validation of the utility of this system for practical industrial usage by isolating high-purity deuterium. We anticipate that this strategy can provide new opportunities for the intelligent design of porous materials leading to the development of other highly efficient isotope and gas separation systems,” said Hoi Ri Moon, the corresponding author of the paper. She adds, "We anticipate that this strategy can provide new opportunities for the intelligent design of porous materials leading to the development of other highly efficient isotope and gas separation systems."

In a paper on the journal Physical Review Letters, a team of researchers at the University of Chicago described their novel technique that can separate isotopes of neon using a beam of gas and unique silicon lattice.

Neon atoms directed at a specially crafted atomic lattice. Credit: Arin R. Greenwood, Federico Giberti, and Kevin J. Nihill.

A supersonic beam of neon, in which all atoms have been accelerated to the same high speed, slams into a silicon crystalline surface whose atoms are arranged in a particular pattern. As a result, atoms are flung off at slightly different angles depending on their isotopic composition. The method could be used for lighter elements on the periodic table, up to about atomic mass 40, as well as small molecules.

"This is a wonderful and very precise demonstration study, and we are very pleased with the results," said Steve J Sibener, a Professor of Chemistry and the supervisory author of the study. "One can think about it like separating the various colors of light into a rainbow using a prism."

What are isotopes? Credit: FuseSchool

Source: JACS/Physical Review Letters

 

About the Author
Graduated with a bachelor degree in Pharmaceutical Science and a master degree in neuropharmacology, Daniel is a radiopharmaceutical and radiobiology expert based in Ottawa, Canada. With years of experience in biomedical R&D, Daniel is very into writing. He is constantly fascinated by what's happening in the world of science. He hopes to capture the public's interest and promote scientific literacy with his trending news articles. The recurring topics in his Chemistry & Physics trending news section include alternative energy, material science, theoretical physics, medical imaging, and green chemistry.
You May Also Like
MAR 14, 2022
Space & Astronomy
2022 NASA Airborne Astronomy Ambassadors Selectees
MAR 14, 2022
2022 NASA Airborne Astronomy Ambassadors Selectees
NASA’s SETI Institute has selected a total of 24 teachers from 13 states as 2022 NASA Airborne Astronomy Ambassado ...
MAY 06, 2022
Space & Astronomy
Two Largest Marsquakes Recorded to Date FTW!
MAY 06, 2022
Two Largest Marsquakes Recorded to Date FTW!
On November 26, 2018, NASA’s InSight Mars Lander touched down on the Red Planet with the purpose of studying the i ...
MAY 01, 2022
Earth & The Environment
Plastic-eating enzyme could prevent plastic waste world domination
MAY 01, 2022
Plastic-eating enzyme could prevent plastic waste world domination
Plastics are a part of our everyday lives, from food containers to soda bottles to soap dispensers to the life-saving ve ...
MAY 06, 2022
Chemistry & Physics
Earth's Atmosphere: A Possible Contributor to the Water on the Moon?
MAY 06, 2022
Earth's Atmosphere: A Possible Contributor to the Water on the Moon?
NASA is working towards landing humans on the Moon in 2024, the first visit in the 21st century. This time the crew ...
MAY 16, 2022
Chemistry & Physics
A Strange 'Black Widow' Pulsar Candidate in Our Galaxy
MAY 16, 2022
A Strange 'Black Widow' Pulsar Candidate in Our Galaxy
Pulsars are remnants of dead stars that die by the process of supernova explosion. These explosions often leave either a ...
MAY 20, 2022
Chemistry & Physics
Mars Rover InSight to End Mission In July
MAY 20, 2022
Mars Rover InSight to End Mission In July
InSight has been on the red planet for over three years, collecting data on its seismic events. However, a layer of dust ...
Loading Comments...