It’s one thing to start a chemical reaction and get a result, but it’s quite another thing to watch it in progress. Rice University chemist Matt Jones wants to see it happen.
Jones has won a prestigious Packard Fellowship for Science and Engineering, a five-year, $875,000 grant to pursue research that stretches his lab’s abilities. The grant is awarded to only 18 early career faculty members a year and is intended to promote new frontiers in their research.
Jones will use the grant to develop techniques in the relatively new field of liquid cell transmission electron microscopy (TEM) to view chemical processes in real time at the atomic scale. The field was the subject of a recent review paper by Jones in ACS Energy Letters.
“TEM is a tried-and-true characterization tool that has been developed for decades and is extremely useful for looking at all kind of things,” said Jones, the Norman and Gene Hackerman Assistant Professor of Chemistry. “It has very high resolution. We can see individual columns of atoms in these images.
“But in order to collect them, the instrument is under high vacuum,” he said. “If you put a liquid in a vacuum, it evaporates.”
Jones learned during a postdoctoral stint at the University of California, Berkeley, to use hermetically sealed cells that trap minute amounts of liquid in a chamber with micron-sized windows that allow the electron beam to pass through.
“This now lets us use all the technology that’s been developed for TEM and leverage it to watch dynamic processes over time in a liquid,” he said.
Better yet, the cells allow liquid to flow into the chamber on demand so reactions can be captured from the start. He said the cells can also be heated or incorporate electrodes for the study of batteries or other electrochemical processes.
Jones’ pitch to the Packard Foundation was to focus the technique on surface reactions, a critical factor in catalysis and other industrial processes. The lab’s initial goals are to capture video of nanocrystal synthesis, protein biofouling of medical devices and catalysis itself.
“I think there’s interesting fundamental scientific questions to pursue in each of those categories, but all three of them have potentially important application ramifications as well,” he said.
The properties of nanocrystals made by the Jones lab are determined by their sizes and shapes, so seeing them form will be a revelation, he said.
“These particles are going to be important for technological applications,” Jones said. “There are now televisions that have quantum dots, so nanocrystals are reaching the stage of commercialization. But fundamentally, we have very little understanding of how they grow.”
The biofouling study will view what happens to medical and other devices “when you put them in a solution with a bunch of proteins, like blood or plasma,” Jones said.
“Whatever the solution, all kinds of things start to stick to the surface and proteins can denature,” he said. “That can elicit an immune response if it’s in your body. If we can watch the process happen, there will be no indirect interpretation of the data. You’ll see exactly what it does.”
Jones called his third area of interest, catalysis, “the quintessential surface science process.”
“There’s been a lot of good, fundamental work in this field, but watching reactions happen to see how individual molecules or particles behave is a piece of information that is unavailable to science at the moment,” he said. “Once we understand how a catalyst works, we can potentially make it more efficient or find materials that accomplish the same reaction that are more abundant and cheaper, use less energy or emit less carbon dioxide.”
Jones said part of the draw to Rice was the suite of advanced electron microscopes installed in 2015 at Brockman Hall. “We have one of the most powerful transmission electron microscopes in North America, and it’s outfitted with spectroscopy equipment,” he said. “Connecting liquid-cell TEM to spectroscopy hasn’t really been done yet, but it’s in our future. It will be neat if we can get spectroscopic information from dynamic processes.”
He expects all the new skills to boost his lab’s primary mission: the bottom-up assembly of nanoparticles into useful inorganic materials, including adaptive materials with unique optical and mechanical properties for metamaterials, energy storage and biological applications.
“We had planned to do all this work regardless, but getting the Packard is the cherry on top,” he said.