Physics News

Sugar, salt, alcohol and a little serendipity led Northwestern University researchers to discover a new class of nanostructures that could be used for gas storage and food and medical technologies. And the compounds are edible. The porous crystals are the first known all-natural metal-organic frameworks (MOFs) that are simple to make. Most other MOFs are made from petroleum-based ingredients, but the Northwestern MOFs you can pop into your mouth and eat, and the researchers have.

"They taste kind of bitter, like a Saltine cracker, starchy and bland," said Ronald A. Smaldone, a postdoctoral fellow at Northwestern. "But the beauty is that all the starting materials are nontoxic, biorenewable and widely available, offering a green approach to storing hydrogen to power vehicles."
"With our accidental discovery, chemistry in the kitchen has taken on a whole new meaning," said Sir Fraser Stoddart, Board of Trustees Professor of Chemistry in the Weinberg College of Arts and Sciences at Northwestern.
"Using natural products as building blocks provides a new direction for an old technology," said Jeremiah J. Gassensmith, a postdoctoral fellow in Stoddart's lab and an author of the paper.
"The metal-organic framework technology has been around since 1999 and relies on chemicals that come from crude oil," explained Ross S. Forgan, also a postdoctoral fellow in Stoddart's lab and co-first author of the paper. "Our main constituent is a starch molecule that is a leftover from corn production."
"Symmetry is very important in metal-organic frameworks," Stoddart said. "The problem is that natural building blocks are generally not symmetrical, which seems to prevent them from crystallizing as highly ordered, porous frameworks."
"We achieved this level of porosity quickly and using simple ingredients," Smaldone said. "Creating metal-organic frameworks using petroleum-based materials, on the other hand, can be expensive and very time consuming."