Mar. 16, 2016

Berkeley Lab-developed tool could help scientists improve catalysts, liquid-crystal displays, more

Here’s a new technology that’s potentially disruptive precisely because it’s non-disruptive: Scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a device that enables NMR (nuclear magnetic resonance) spectroscopy, coupled with a powerful molecular sensor, to analyze molecular interactions in viscous solutions and fragile materials such as liquid crystals.
In a first, their method allows the sensor, hyperpolarized xenon gas, to be dissolved into minute samples of substances without disrupting their molecular order.

The technique brings the analytic power of hyperpolarized-gas NMR to materials that are too fragile to accept xenon gas through bubbling or shaking, which are the conventional delivery methods. It could help scientists learn more about advanced polymers, filters and catalysts for industrial processes, and liquid-crystal displays, to name a few applications.
The research was performed in the lab of NMR pioneer Alexander Pines, a senior faculty scientist with Berkeley Lab’s Materials Sciences Division and UC Berkeley’s Glenn T. Seaborg Professor of Chemistry. Ashley Truxal and Clancy Slack, who are UC Berkeley graduate students and members of Berkeley Lab’s Materials Sciences Division, conducted the research with several other scientists.

Their work was published online March 8 in the journal Angewandte Chemie.
“Our device provides a new, robust way of introducing hyperpolarized xenon gas into a sample without perturbing the order of its molecules,” says Pines. “It will allow us to use NMR to study new types of viscous and fragile materials, as well as materials that hierarchically aggregate into more complex structures, such as synthetic membranes and biological cells.”

Image: This illustration shows how the new method works. Hyperpolarized xenon-129, which can sense molecular ordering within samples, diffuses through hollow membrane fibers containing viscous liquids. Different chemical environments, including phases (gas, liquid or solid) and types of molecular order, correspond to highly resolved xenon-129 chemical shifts. This is represented by different colors of xenon atoms.