By modifying the underlying network of cellulose fibers, etching off surface “fluff” and applying a thin chemical coating, researchers at Georgia Institute of Technology, Atlanta, have created a new type of paper that repels a wide variety of liquids, including water and oil.
The paper uses the same technique used naturally by leaves of the lotus plant to repel liquids by creating surface patterns at two different size scales plus the application of a chemical coating. The material, developed at Georgia Tech, uses nanometer- and micron-scale structures, plus a surface fluorocarbon, to turn old-fashioned paper into an advanced material.
The modified paper could be used as the foundation for a new generation of inexpensive biomedical diagnostics in which liquid samples would flow along patterns printed on the paper using special hydrophobic ink and an ordinary desktop printer. This paper could also provide an improved packaging material that would be less expensive than other oil- and water-repelling materials, while being both recyclable and sustainable.
The researchers have printed patterns onto their paper using a hydrophobic ink and a desktop printer. Droplets applied to the pattern remain on the ink pattern, repelled by the adjacent superamphiphobic surface.
