The team's solution-based technique, published in the peer-reviewed journal Proceedings of National Academy of Sciences, was discovered serendipitously when a transparent film of polymer spread up the walls of a container while nanofibers in water were being purified with chloroform.
"What drew me in immediately was the eerie phenomenon of what appeared to be self-propelled fluid flow," said Julio M. D'Arcy, lead author on the PNAS paper and a senior graduate student in the Kaner's UCLA lab.
"Now I can tell people that I make films in L.A.," he joked.
When water and oil are mixed, a blend of droplets is formed, creating a wateroil interface that serves as an entry point for trapping polymer nanofibers at liquidliquid interfaces. As droplets unite, a change in the concentration of blended solids at the wateroil interface leads to a difference in surface tension. Spreading up a glass wall occurs as result of an attempt to reduce the surface-tension difference. Directional fluid flow leads to a continuously conductive thin film comprised of a single monolayer of polymer nanofibers. The uniformity of the film surface is due to the particles being drawn out of the wateroil interface, sandwiched between two fluids of opposing surface tensions.
Development of the technology is occurring in collaboration with Fibron Technologies Inc., with support from the National Science Foundation through a Small Business Technology Transfer grant. Fibron is a small company that has licensed the technology from UCLA. It was founded by Kaner, who serves as chief scientific adviser, and two of his former Ph.D. students Christina Baker and Henry Tran, who have gone on to take leadership roles in the company.
Fibron's CEO, Christian Behrenbruch, said "working with UCLA to develop this
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