Multi-functional fluorinated ionic liquid infused slippery surfaces with dual-responsive wettability switching and self-repairing

Abstract

Stimuli responsive slippery surfaces with controllable wettability have attracted much attention due to their potential application in many fields. However, most of these surfaces only adopted paraffin as the lubricant oil and achieved wettability transformation just by heating. In addition, the self-repairing properties of smart slippery surfaces have rarely been reported. Hence, challenges still remain in fabricating multiple responsive slippery surfaces based on other lubricants possessing self-repairing properties. Here, a smart slippery surface with controllable wettability was fabricated by using solid/liquid fluorinated ionic liquids (FILs) as lubricants and fluoropolymer films as the underlying substrates. The FIL, a thermo-responsive phase-transition material, was synthesized by ionic exchange and the substrate exhibited good self-repairing properties and magnetic-thermal and photo-thermal responses. By tuning the substrate temperature under light irradiation or magnetic field to change the phase state of the FIL, the surface could realize wettability conversion. Besides, the responsive temperature can be adjusted by tuning the melting temperature (T_m) of the FIL. The FIL was first synthesized and there was no report employing FILs as the lubricants to realize the wettability change of slippery surfaces. This work provided a new type of lubricant to prepare intelligent slippery surfaces, thus advancing the application of slippery surfaces in liquid transport devices.