Scientists Develop All-Natural Sponge That Detects, Captures & Stores Carbon Dioxide

Scientists have developed porous crystals – known as metal-organic frameworks – made from sugar, salt, and alcohol that can efficiently detect, capture, and store carbon dioxide.

AsianScientist (Sep. 28, 2011) – A year ago, Northwestern University chemists published their recipe for a new class of nanostructures made of sugar, salt, and alcohol.

Now, the same team, working in the laboratory of Sir Fraser Stoddart at Northwestern University and with collaborators at KAIST in South Korea, has discovered the edible compounds can efficiently detect, capture, and store carbon dioxide. And the compounds themselves are carbon-neutral.

Their findings are published in the latest issue of the Journal of the American Chemical Society (JACS).

The porous crystals – known as metal-organic frameworks (MOFs) – are made from all-natural ingredients and are simple to prepare, giving them a huge advantage over other MOFs.

Conventional MOFs, which also are effective at adsorbing carbon dioxide, are usually prepared from materials derived from crude oil and often incorporate toxic heavy metals.

“We are able to take molecules that are themselves sourced from atmospheric carbon, through photosynthesis, and use them to capture even more carbon dioxide,” said Dr. Ross Forgan, a co-author of the study.

“By preparing our MOFs from naturally derived ingredients, we are not only making materials that are entirely nontoxic, but we are also cutting down on the carbon dioxide emissions associated with their manufacture.”

The main component, gamma-cyclodextrin, is a naturally occurring biorenewable sugar molecule that is derived from cornstarch and it is the precise arrangement of the sugars in the crystals that is vital to their successful capture of carbon dioxide.

“It turns out that a fairly unexpected event occurs when you put that many sugars next to each other in an alkaline environment — they start reacting with carbon dioxide in a process akin to carbon fixation, which is how sugars are made in the first place,” said lead author Dr. Jeremiah Gassensmith.

The unusual reaction between carbon dioxide and the MOF has led to a simple method of detecting carbon dioxide: the researchers place an indicator molecule, which detects changes in pH by changing its color, inside each crystal. When the yellow crystals of the MOFs are full of carbon dioxide they turn red, and the carbon capture process is reversible.

The simplicity of the new MOFs, allied with their low cost and green credentials, have marked them as candidates for further commercialization.

The article can be found at: Gassensmith JJ et al. (2011) Strong and Reversible Binding of Carbon Dioxide in a Green Metal–Organic Framework.

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Source: Northwestern University.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Anusuya Das received a Ph.D. in Biological Engineering from Massachusetts Institute of Technology (MIT), USA, and a B.A. in Bioelectrical/Cellular-Molecular Engineering from Arizona State University, USA. Anusuya is currently a post-doctoral researcher at the University of Virginia, USA.

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