A comparative study of the icephobic and self-cleaning properties of Teflon materials having different surface morphologies

Materials having fluorocarbon bonds are among the best candidates for the fabrication of superhydrophobic surfaces. Here, we describe two facile, non-expensive, and industrialized approaches to produce superhydrophobic Teflon materials having ultra-water repellency, icephobic, and self-cleaning properties. Direct replication and plasma-treatment approaches produced Teflon sheets having very different surface patterns, i.e. microstructures and micro- nanostructures. Neither approach altered the chemical composition of the original Teflon surfaces. Rice leaf–like microstructures were produced on the replicated surface, whereas lotus leaf–like hierarchical micro-nanostructures characterized the plasma-treated surface. Water droplets rolled off the micro-nanostructured surfaces ~10% faster than off the microstructured surfaces. The micro-nanostructured surface also produced more rebounds for a water droplet during the impact test. Although both surfaces possessed similar self-cleaning properties, the micro-nanostructured surface reduced ice adhesion to a greater degree than the microstructured surface. The more effective ice repellency of the micro-nanostructured surface was due to its surface morphology that reduced the interlocking of ice inside the surface asperities. However, the microstructured surface delayed considerably the onset of freezing of a water droplet due to the larger micro-air pockets trapped within its surface asperities.