Slippery liquid-infused substrates: A versatile preparation, unique anti-wetting and drag-reduction effect on water

Newly developed slippery liquid-infused porous surfaces (SLIPSs) are highly promising for a broad range of applications. However, a major challenge remains in developing generalized methods to manufacture SLIPSs on versatile substrates. Herein, we report a simple and inexpensive method for forming SLIPSs by infusing a lubricating liquid into a nanoparticle-polymer film. We show that a stable liquid interface can repel various liquids (e.g., water, oil and ethanol) and maintain low contact angle hysteresis (<5°). The resulting gel-like porous film is mechanically robust. The repellency of the as-prepared SLIPSs is maintained even after exposure to continuous flow for several hours. By comparing the friction on a normal surface and on the SLIPSs at different flow velocities, we demonstrate that the as-prepared SLIPSs exhibited a drag reduction of ∼7% at a low wall shear rate. This study not only presents a convenient approach to create SLIPSs on arbitrary materials but also shows a drag-reducing effect and self-cleaning properties. We envision that our findings will be helpful in designing SLIPSs for broad applications, such as low-cost water transportation and oil pipelines.