I wrote the piece below for Australasian Science a few months ago. I had too many stories for my nine pages of Browse that month and it didn’t run, nor the next two months. But last month I was a few stories short and Guy went through those that had missed the cut in previous months and used them. This one wasn’t included. I asked him about it, and he told me he thought it was “too dense” and anyway it was not too old to run. Personally I think it’s an interesting topic. I also like it because one of the researchers is the wife of my best friend (something I only found out after I had nearly finished it) and it was published in Nature (well Nature Communications). Also the title reminds me of Neil Stephenson’s The Diamond Age. Obviously running it here doesn’t make up for it missing the cut in Australasian Science, but it’s the best I can do.
A better way to produce crystals with enormous surface areas could unlock the path to the practical storage of hydrogen and diverse other uses.
A lattice structure means single gram of Metal Organic Framework (MOF) crystals can have a surface area of more than 4500 m2. The size of the pores in the lattice, determines the molecules that can be stored inside.
Although MOFs are relatively new structures, but they have aroused great excitement. Possible uses include the delivery of drugs to appropriate parts of the human body and the detection of low doses of toxins.
Most excitement has focussed on the possibility that the large surface areas could be used to hold huge quantities of gasses, particularly hydrogen, in small volumes. Gases in MOFs have higher densities than when squashed at pressure.
Reduced pressures can be used to release the gasses when they are needed. MOFs might also be useful for capturing carbon dioxide, although the gas would need to be extracted for long-term storage.
Commercial viability is hindered by slow growth and difficulties in controlling MOF shapes. However, researchers from CSIRO Future Manufacturing believe work published Nature Communications will make the production of MOFs far easier and more effective.
“To address these problems, we have developed a new technique known as seeding which allows the user to have complete control over where and how the MOF crystals grow. Additionally the seeding technique greatly speeds up the growth process,” says Dr Dario Buso. ““We have discovered that the MOF crystals grow in a completely ordered and predictable way once we introduce ceramic spherical microparticles – known as seeds – into the MOF solution.”
The zinc phosphate microparticles can be adjusted to alter MOF specifications. Previously specification required the use of chemical vapour deposition after the framework was formed, which reduced the capacity to select pore sizes for a particular molecule.
“By controlling the placement of the seeds we can control how and where the MOFs grow – even on complex three-dimensional surfaces,” says Buso.
“To fully exploit the flexibility of MOFs we wanted to see if we could give the material additional properties using our new technique,” says lead author Dr Paolo Falcaro. “We were excited to find that it was relatively straightforward to embed active nanoparticles into the seed and then embed the seed inside the MOF.
Team member Dr Kate Nairn adds that MOF’s may also be used to surround catalysts so that only certain chemicals in a solution can reach it, preventing the catalyst from becoming poisoned.