When it comes to water, some materials have a split personality - and some of these materials could hold the key to new ways of harnessing solar energy. These small assemblies of organic molecules have parts that are hydrophobic, or water-fearing, while other parts are hydrophilic, or water-loving. Because of their schizoid nature, micelles organize themselves into spheres that have their hydrophilic parts turned out while their hydrophobic parts are shielded inside.

A new study from the U.S. Department of Energy's (DOE's) Argonne National Laboratory has shown water can serve another previously undiscovered role as these micelles coalesce to spontaneously form long fibers.

In a study led by Argonne nanoscientist Subramanian Sankaranarayanan and chemist Christopher Fry, both of Argonne's Center for Nanoscale Materials, supercomputer simulations and as well as lab-based experiments showed that water serves as an invisible cage for the growth of the micelle fiber.

The study could help scientists to understand how light-harvesting molecules are incorporated into the micelle fiber as it assembles, which would be a key step to understanding some forms of artificial photosynthesis.

"Until now, trying to understand where the light-harvesting molecules bind has been like trying to see how a square peg can fit in a round hole," said Sankaranarayanan. "By seeing the way in which the micelle fiber self-assembles, we can get a better understanding of how these kinds of light-harvesting systems are formed."