(214b) Two-Step Process to Create “Roll-Off” Superamphiphobic Paper Surfaces

The fabrication of anti-wetting surfaces has gained increased attention during recent years; of particular interest is the achievement of superamphiphobic (superhydrophobic and superoleophobic) materials. For anti-wetting applications such as disposable non-stain clothes, low cost medical testing strips or packages for liquids and food, paper has many merits over polymeric or glass containers such as breathability, low cost, recyclability and texture. In this study, the fabrication of paper which repels organic liquids with a surface tension as low as 27.5 mN/m (n-hexadecane) is reported. Paper was exposed to a 30 minute oxygen plasma followed by a 15 minute vapor-phase silanization with fluoroalkyl trichlorosilane. The resulting surfaces cause all test liquids (water, diiodomethane, motor oil and hexadecane) to â??bead upâ? and readily roll off the treated surface. Unlike the widely used approach that relies on the deposition of nanoparticles to achieve superamphiphobic surfaces, this method results in good adhesion between coating and the paper substrate. Anti-wetting behavior and surface stability were determined by contact angle measurements and surface XPS analysis after dynamic impact tests. The surface modification process is simple and does not produce any waste liquid. Furthermore, the superamphiphobic paper has high gas permeability due to pore volume enhancement by plasma etching, but maintains the mechanical flexibility and strength of untreated paper.