A world record for highest-surface-area materials
September 13, 2012
The internal surface area of just one gram (1/28 of an oz.) of NU-110 (model shown here) would cover one-and-a-half football fields, making it ideal for natural-gas and hydrogen storage (credit: Northwestern University)
Northwestern University researchers have broken a world record by creating two new synthetic materials with the greatest amount of surface areas reported to date.
Named NU-109 and NU-110, the materials belong to a class of crystalline nanostructure known as metal-organic frameworks (MOFs) that are promising vessels for natural-gas and hydrogen storage for vehicles, and for catalysts, chemical sensing, light harvesting, drug delivery, and other uses requiring a large surface area per unit weight.
The materials’ promise lies in their vast internal surface area. If the internal surface area of one NU-110 crystal the size of a grain of salt could be unfolded, the surface area would cover a desktop.
Put another way, the internal surface area of just one gram (1/28 of an oz.) of NU-110 would cover one-and-a-half football fields.
Closeup of one NU-100 cage design (gray: carbon; red: oxygen; teal: copper; purple: size of the largest sphere that can fit with the cage (credit: Northwestern University)
The extremely high surface area was achieved using a carbon dioxide activation technique. As opposed to heating, which can remove the solvent but also damage the MOF material, the carbon dioxide-based technique removes the solvent gently and leaves the pores completely intact.
MOFs are composed of organic linkers held together by metal atoms, resulting in a molecular cage-like structure. The researchers believe they may be able to more than double the surface area of the materials by using less bulky linker units in the materials’ design.
The researchers also showed that the theoretical upper limit for MOF surface areas is 14600 m2/g (one gram of material would cover 2.7 American football fields), possibly higher.
The two MOFs display the highest experimental Brunauer-Emmett-Teller surface areas of any porous material on record, 7,000 m2/g; that is, one kilogram of the material contains an internal surface area that could cover seven square kilometers. (Brunauer-Emmett-Teller, or BET, is an analysis technique for measuring the surface area of a material.)
The MOF’s designing and synthesizing technology is being commercialized by NuMat Technologies, a Northwestern startup.
UPDATE 9/13/2012: added video and mention of storing hydrogen.
Comments (16)
by Felipe
Hmm. Ok, but it should be a struggle to filter the crystals in case of energy storage, mainly because you want to work with high pressures. Also in drug delivery you should be very cautious in case the crystals spread. MOFs are ok, but the “powder” state constrains the uses.
by NakedApe
I wonder if it would be useful to use an evolutionary algorithm to ‘breed’ new materials. Evolution has a way of finding counter-intuitive, but highly successful solutions.
by Cybernettr
This was one of the best, most well-produced, clearest video demonstrations I’ve ever seen!
by Editor
Agreed
by Guillermo
+1!
by Espen
This is great news. I see that it says one kilogram (kg) would cover seven square kilometres. Wouldn’t that be one gram would cover seven square kilometres? (1,000 m2 = 1 km2). In that case one kilogram would cover 7,000 square kilometres…. or an area a little bit bigger than Delaware :) http://www.enchantedlearning.com/usa/states/area.shtml
And according to wikipedia it should be perfect for Hydrogen storage: http://en.wikipedia.org/wiki/Metal-organic_framework
by Editor
Espen, it’s a tricky calculation. As I understand it: 7000m² = 0.0070km² so with kg, the area would be 1000 times 0.0070, or 7 km²
by Espen
Doh. Of course you are right. A little early in the morning in my part of the world when I wrote that. Anyway, just enthusiastic about progress :)
None the less, still amazing!
by Qwerty Jones
@Espen A square kilometer is a square with each side measuring 1000 meters. Therefore 1km2=1000×1000
(1,000 000 m2 = 1 km2). – yes, a million sq. meters.
1kg per 7 square kilometers sounds amazingly efficient.
by Christopher Wilmer
Hi, I am one of the co-authors of this research. More information about our MOFs can be found in this video:
http://www.youtube.com/watch?v=QaKSekjAnqY
by Editor
Hi, Christopher. Awesome video! Just added to the post.
by Christopher Wilmer
My research finally makes it onto Kurzweilai.net … awesome!
by Editor
So what are the hot products we can expect from NuMat? Will you enable hydrogen and methane cars?
by Gorden Russell
As good as it is to run a vehicle on natural gas, hydrogen will be the only fuel someday.
by Bri
If I’m not mistaken it could be used with hydrogen for hydrogen powered vehicles.
by Editor
Hydrogen storage: right, thanks. Added.