Researchers have developed new edible nanostructures which could be used to store gases such as hydrogen to power our cars.
Using sugar, salt and alcohol, a team of scientists at Northwestern University, Illinois, have managed to construct crystals which could store gases needed as fuel or for use within the medical and food technology sectors.
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, just as 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.”
Smaldone is co-first author of a paper about the edible MOFs published by Angewandte Chemie. The study is slated to appear on the cover of one of the journal’s November issues.
Metal-organic frameworks are well-ordered, lattice-like crystals. The nodes of the lattices are metals (such as copper, zinc, nickel or cobalt), and organic molecules connect the nodes. Within their very roomy pores, MOFs can effectively store gases such as hydrogen or carbon dioxide, making the nanostructures of special interest to engineers as well as scientists.
Of course the scientists did not use ordinary sugar you might find at home but gamma-cyclodextrin, an eight-membered sugar ring produced from biorenewable cornstarch. The salts can be potassium chloride, a common salt substitute, or potassium benzoate, a commercial food preservative, and the alcohol is the grain spirit Everclear.
With these ingredients in hand, the researchers actually had set out to make new molecular architectures based on gamma-cyclodextrin. Their work produced crystals. Upon examining the crystals’ structures using X-rays, the researchers were surprised to discover they had created metal-organic frameworks — not an easy feat using natural products.
The results of the research are published in a paper entitled ‘Metal–Organic Frameworks from Edible Natural Products’.
