Liquid spreading is of significant interest in science and technology. Although surface topography engineering and liquid surface-tension regulating can facilitate spreading, the spreading layers in these strategies are inevitably inhomogeneous or contaminated with surfactants. Herein, we show a general strategy to realize the superspreading of liquids on mutually soluble gel surfaces. The cooperation of the hydraulic pressure under liquid phase and liquid-like property of gel surfaces can dramatically eliminate the local pinning effect and enhance the advancement of three-phase contact line, thus forming stable and homogeneous superspreading liquid layers. Such liquid layers can be converted into various functional thin polymer films with controlled thicknesses (nm- to µm-scale) through one-step polymerization of the reactants. Our strategy offers opportunities for large-scale synthesis of versatile functional thin films for various applications. 

Angewandte Chemie, 2016 

Spontaneous liquid superspreading on gel surfaces in a liquid/liquid/gel tri-phase system. a) Illustration and images of the superspreading processes of a water droplet (5 μL) achieves on PAAm hydrogel surfaces. b) Illustration and images of the superspreading processes of a chloroform droplet (5 μL) rapidly and completely spreading and forming an oil layer on the chloroform-swollen P(BMA-co-LMA) organogel surface. Illustrations of the spreading coefficient S of liquid droplets spreading on gels c) in air, d) under oil, and e) under water.