Air Force funds research into oil repellent surfaces Published Jan. 23, 2008 By Maria Callier Air Force Office of Scientific Research Public Affairs ARLINGTON, Va. -- The Air Force Office of Scientific Research is funding investigations into super oil repellent surfaces because of their potential utility in cleaning up jet fuel spills and protecting aircraft or rocket parts from fuel absorption. Drs. Gareth H. McKinley and Robert E. Cohen, professors of engineering at the Massachusetts Institute of Technology, are exploring man-made and natural surfaces that keep gasoline and oil from soaking in and spreading out over a surface. The challenge is the low value of the surface tension of many oils, which makes them spread over surfaces very easily. Surface tension is a measure of the attraction between molecules of the same composition. The researchers' goal is to design new solid surfaces with very low interfacial energies that can repel oily liquids. In an MIT news article by Anne Trafton, Dr. McKinley noted that "Nature has developed a lot of methods for waterproofing, but not so much oil-proofing. The conventional wisdom was that it couldn't be done on a large scale without very special lithographic processes, which duplicate micro-components." After studying the water repellent surfaces of lotus leaves, Drs. McKinley and Cohen created a microfiber fabric that can be deposited onto aircraft surfaces via a process known as electrospinning. The microfibers contain fluorinated nanoparticles, FluoroPOSS, which are synthesized by Dr. Joe Mabry and colleagues at Edwards Air Force Base, Calif. "It's the combination of chemistry on the nanoscale level and fiber structure on the micrometer scale that gives rise to our materials' oil-repelling nature," said Dr. McKinley in the article. According to Dr. Charles Lee, AFOSR program manager for the project, "Many people are addressing materials that repel water, but not too many are researching oil repellents, a research topic which is important for many Air Force systems. This collaborative research involving scientists at MIT, and Edwards Air Force Base will be important for making future systems more maintenance free." The scientists' work may lead to protective coatings for airplane parts, which are vulnerable to fuel leaks. The researchers may also create fuel-line gaskets with the new technology because gaskets typically swell substantially when they absorb gasoline. Air Force officials say they hope that such materials will significantly address the effects of fuel spills, making clean-up of fuel or oil-soaked equipment far easier.