Anti-smudge behavior of facilely fabricated liquid-infused surfaces with extremely low contact angle hysteresis property

Slippery liquid-infused porous surfaces (SLIPS) possess excellent liquid-repellency and have been applied for anti-icing and anti-fouling. Following the concept of SLIPS, a liquid-infused surface is facilely fabricated by a stretched polytetrafluoroethylene (PTFE) thread seal tape infused with perfluoropolyether fluorinated lubricant. Owing to the thin thickness of the PTFE film, this surface can be transparent and flexible. The nearly hysteresis-free property of SLIPS is manifested by the absence of hysteresis loops in the plot of contact angle (or base diameter) versus drop volume for both water and hexadecane. The anti-smudge behavior of the surface is first examined by the removal of stains by sliding drops at an inclined plane. Secondly, the anti-smudge behavior of the surface is demonstrated by the wetting competition of a hexadecane drop between SLIPS and fluorinated polyvinyl alcohol surface which is lipophobic and superhydrophobic. Because of the negligible contact angle hysteresis, almost no liquid (only 3.9%) is seized by the SLIPS after rupture. A Surface Evolver simulation is performed to understand the mechanism of the wetting competition and the result is in a good agreement with that of the experiment. Our tests indicate that the liquid-infused surface exhibits excellent anti-smudge properties.