Press releases are typically rather dry material and not exactly prone to humor, but researchers at Savannah Research National Laboratory (SRNL) preface the news release for their impactful glass microsphere breakthrough, with a riddle. "What looks like a fertilized egg, flows like water, gets stuffed with catalysts and exotic nanostructures and may have the potential of making the current retail gasoline infrastructure compatible with hydrogen-based vehicles of the future – not to mention also contributing to arenas such as nuclear proliferation and global warming?"

The Bulletin, the monthly magazine of The American Ceramic Society, carries their answer (PDF).  Unlike many press releases, their work is truly very different than other existing research in that it represents a whole new class of materials that can be used for diverse storage purposes, by having properties similar to both a liquid and being solid in form.  The new material consists of tiny hollow spheres, known formally as Porous Wall-Hollow Glass Microspheres (PW-HGM). 

The spheres measure a scant 2-100 microns in diameter.  This puts them at smaller than the width of a human hair.  The key asset of the spheres are tiny pores which adorn their surface.  These pores can be controlled by processing to measure from 100 to 3,000 Angstroms and they form full tunnels between the inner and outer wall, through which chemicals of controlled sizes can pass.

SRNL Researchers G.G. Wicks, L.K. Heung, and R.F. Schumacher led the project.  In it they showed hydrogen and other gas adsorbents, as well as other chemicals, could be pumped in through the pores.  This allows for relatively safe solid-state storage of hydrogen or other reactive gas by limiting their exposure to the atmosphere, with which they would react.

The new research treads on foreign ground, as the tiny nanoscale pores have never been seen before.  The tiny structures were photographed in a series of images taken by the researchers. 

A major application of the new material is gas streaming filtering.  By adjusting the porosity, the material will act as a filter, absorbing one type of gas and letting the others pass.

Most promising yet, the microballoons can have their mechanical properties tweaked to act like a fluid, including flowing along pipes.  This means that current gas distribution infrastructures could be modified to transport solid hydrogen, with little change.  This in turn would amount in savings of money and effort spent.  The hardy little microballoons are also easily recycled and reused, thanks to their strength.

The research is not going unnoticed.  Toyota is sponsoring the SRNL to bring the technology to market to help it with its hydrogen vehicles.  Gas purification and separation companies are also making deals with SRNL.  And the Medical College of Georgia is working closely with SRNL researchers to apply a modified version of the microballons for drug delivery.  In total the Lab has over a dozen partnerships or collaborations.

The research is truly quite exciting and unique, it’s good to see it getting such attention from big names in commerce and academia.  With this new class of materials, scientist will have an entirely new material, which treads the solid-liquid barrier offering many unique properties that are the best of both worlds.