Gel-Infused Slippery Surface with Enhanced Longevity and Thermally Controllable Sliding Properties

Smart surfaces with stimuli responsive wetting behavior can potentially be important materials in a number of applications. Demonstrated here is a novel method to fabricate a gel-infused slippery surface by impregnating a nanostructured surface with a gelator containing lubricant, in this case 12-hydroxystearic acid in mineral oil. The resulting surface exhibits temperature-dependent and gelator-concentration-dependent water drop sliding properties. In some cases, this means temperature-dependent transition from water pinning to water sliding surfaces. These water drop sliding properties are shown to correlate with the temperature sensitive rheology of the gelled oil. The robustness of the lubricant layer against wash, a big concern for slippery liquid-infused surfaces, is proved to be enhanced by the addition of gelator, and an optimal 0.5 wt% concentration of gelator in mineral oil is found to best preserve the surface properties under a moderate shear flow.