(322i) Investigation of a Simultaneously Hydrophilic and Oleophobic Ionic Liquid Coating

Surfaces that are more wettable to water than to oils are highly desired in a range of applications such as oil/water separation enhancement, detergent-free cleaning, and anti-fogging coatings. Unfortunately, such surfaces are rare, and the underlying mechanism of their wetting behavior remains unclear. Moreover, the reported surfaces are usually short-lived or only mildly effective. The tunable nature of ionic liquids (ILs) makes them an attractive coating material, offering endless possibilities for customization and optimization. Here we demonstrate the successful development of a novel functionalized ionic liquid coating with highly fluorinated alkyl segments. This nanometer-thick coating promotes a high degree of oleophobicity on Si substrates due to the high fluorination, while maintaining a water contact angle (WCA) below 10^o and is observed to be stable over at least 48 hours. These results indicate that the development of functionalized ionic liquid coatings with highly fluorinated segments holds great potential for addressing the challenges of creating surfaces that are simultaneously hydrophilic and oleophobic. Further investigation into the underlying mechanism and optimization of these coatings could lead to their widespread use in a variety of applications that require surfaces with controlled wettability.