EnlargePosted on 08/15/2013 8:47:20 AM PDT by neverdem
Credit: Simon Ydhag, Uppsala University
Credit: Simon Ydhag, Uppsala University
Researchers in Uppsala, Sweden accidentally left a reaction running over the weekend and ended up resolving a century-old chemistry problem. Their work has led to the development of a new material, dubbed Upsalite, with remarkable water-binding properties. Upsalite promises to find applications in everything from humidity control at home to chemical manufacturing in industry.
Maria Strømme and colleagues at Uppsala University, whose work appears in the journal PLOS ONE, have modified a procedure dating back to 1908 to make a powdered and dry form of magnesium carbonate (MgCO3). The reaction ingredients are all cheaply available: magnesium oxide (MgO) and carbon dioxide (CO2), dissolved in methanol, a common industrial solvent. The result is pure, dry MgCO3.
Dry in this case means very dry. In the chemical sense, it means void of almost any water molecules at all.
Crystalline forms of dry MgCO3, which lack the structure needed to absorb water, are readily synthesised at high temperatures (over 100 °C). As early as 1820, people started to search for lower-temperature routes to make dry MgCO3, but none have successfully yielded pure product until now. This is why Upsalite has been described as an "impossible material".
The key modification was to increase the pressure of CO2 to three times that of normal atmospheric pressure, rather than simply bubbling the gas through a mixture of MgO in methanol. When one mixture was accidentally allowed to react over a long weekend, researchers came back to find a gel. It turns out the gel was formed because methanol molecules had been trapped within the material. When heated to 70 °C, which is above the boiling point of methanol, the gel "solidifies and collapses into a white and coarse powder". Analysis confirmed that the product was just what chemists had been trying to make for more than 100 years – a dry, powdered form of MgCO3.
Upsalite has impressive properties as a desiccant, absorbing water better than the much more expensive materials that are currently used (called zeolites). Most of the absorbed water is retained when Upsalite is transferred from a humid to a very dry environment. The dry form can be regenerated by heating to 95 °C. By contrast, most zeolites need to be heated to over 150 °C in order to dry them. Not only is Upsalite easy to make and reuse, but it is also not toxic to humans, which makes it suitable for humidity control indoors.
The impressive drying property stems from the very large internal surface area of Upsalite. MgCO3 is a common mineral that occurs in a variety of forms, most of which have water bound to their surface and are crystalline. By contrast, Upsalite has no water integrated into its structure and is not crystalline. Instead, it is mesoporous – a structure with pores that are a million times smaller than the width of a human hair – which provide it with a much greater surface area.
The past 20 years have seen a surge of interest in mesoporous materials such as zeolites and carbon nanotubes due to their ability to selectively absorb small molecules, which may enable applications in drug delivery, pollution removal, and the development of new catalysts for chemical reactions. Recognizing these prospects, the researchers have founded a spin-out company called Disruptive Materials to commercialise and apply Upsalite.
More information: Forsgren J, Frykstrand S, Grandfield K, Mihranyan A, Strømme M (2013) A Template-Free, Ultra-Adsorbing, High Surface Area Carbonate Nanostructure. PLoS ONE 8(7): e68486. DOI: 10.1371/journal.pone.0068486
Abstract
We report the template-free, low-temperature synthesis of a stable, amorphous, and anhydrous magnesium carbonate nanostructure with pore sizes below 6 nm and a specific surface area of ~ 800 m2 gm-1, substantially surpassing the surface area of all previously described alkali earth metal carbonates. The moisture sorption of the novel nanostructure is featured by a unique set of properties including an adsorption capacity ~50% larger than that of the hygroscopic zeolite-Y at low relative humidities and with the ability to retain more than 75% of the adsorbed water when the humidity is decreased from 95% to 5% at room temperature. These properties can be regenerated by heat treatment at temperatures below 100°C.The structure is foreseen to become useful in applications such as humidity control, as industrial adsorbents and filters, in drug delivery and catalysis.
Source: The Conversation
This story is published courtesy of The Conversation (under Creative Commons-Attribution/No derivatives).
For those of us who like to keep our powder and irons dry...
The day the ocean disappeared.
Historians trace the disappearance of the Mediterranean Ocean to the sinking of a bulk chemical freighter off the coast of Tunisia. The ship recently came through the Suez Canal and was transporting 750 metric tons of Upsalite when it came under rocket attack by unknown forces. The double hull was breached and sea water rushed into the hold triggering the cataclysmic reaction. It is believed that the disappearance of the weight of the sea water caused an earthquake that sealed the Med off at Gibraltar.
Then they put it in a bottle, shook it all up, and invented upsy-daysyum.
Looks like you beat me to it, in a way.
One of the interesting aspects of nanotechnology is the substantial increase of surface area. Physical grinding wouldn’t approach it, but if it did it would be much more costly.
I think the “discovery” in there is the usage of high pressure to make the manufacturing process much more efficient. This is more a question of thermodynamics than chemistry.
Irony is that this would prove the falsity of fossile fuel equal globla warming because fossile fuels are made in a natural earth high pressure environment difficult to reproduce when using corn to synthesize.
All matter of control and coopting.
About half the time when I run the AC I am not looking for it to be cooler I just want the air a bit drier. When the fish is swimming above his bowl you know it is a bit humid. Open a jar of this stuff and heyo-presto.
With a lifetime supply of survival food from foodinsurance.com kept humidity proof by Upsalite.
I think we are full circle now lol
I can just see the little packets of dessicant made from this in the near future labeled "GO AHEAD AND EAT"
Don't worry - Kurt Vonnegut's "Ice 9" might be an effective antidote if applied immediately, LOL.
Sean is now set for life for advertisers.
Sean, I’ll be waiting for my Ruth’s Criss gift certificate.
Thank me for all my efforts!
Any word on cavorite?
I wonder if you can generate a water supply with this stuff- just run outdoor air throught it, isolate, bake it off with solar heating, condense, repeat. Another technology to live off the grid?
Should they call it Oopsalite?
Ding! Ding! Ding! Winner Post! LOL!
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FReepmail me if you want on or off my health and science ping list.
Good point, but you already have dessicants for that.
Lolz
The possibility of making your own petro just went up.
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