Non-wetting Liquid-Infused Slippery Paper

Abstract

Liquid-infused slippery surfaces have replaced structural superhydrophobic surfaces in a plethora of emerging applications, hallmarked by their favorable self-healing and liquid-repelling characteristics. Their ease of fabrication on different types of materials and increasing demand in various industrial applications have triggered research interests targeted toward developing an environmental-friendly, flexible, and frugal substrate as the underlying structural and functional backbone. Although many expensive polymers such as polytetrafluoroethylene have so far been used for their fabrication, these are constrained by their compromised flexibility and non-ecofriendliness due to the use of fluorine. Here, we explore the development and deployment of a biodegradable, recyclable, flexible, and an economically viable material in the form of a paper matrix for fabricating liquid-infused slippery interfaces for prolonged usage. We show by controlled experiments that a simple silanization followed by an oil infusion protocol imparts an inherent slipperiness (low contact angle hysteresis and low tilting angle for sliding) to the droplet motion on the paper substrate and provides favorable anti-icing characteristics, albeit keeping the paper microstructures unaltered. This ensures concomitant hydrophobicity, water adhesion, and capillarity for low surface tension fluids, such as mustard oil, with an implicit role played by the paper pore size distribution toward retaining a stable layer of the infused oil. With demonstrated supreme anti-icing characteristics, these results open up new possibilities of realizing high-throughput paper-based substrates for a wide variety of applications ranging from biomedical unit operations to droplet-based digital microfluidics.

Water-repelling behavior of the 1-D hematite nano-network

“…Such a surface may behave like an ''adhesive Cassie''-type surface. 68,69 The water contact angle on the irradiated surface was calculated theoretically using the Cassie model by considering the average pore diameter of 50 nm (Fig. 1(c)) and a thickness of 1.01 mm for the nanonetwork, yielding a contact angle of about 921, which is within the range of observed angles in Fig.…”

Engineered Sustainable Omniphobic Coatings to Control Liquid Spreading on Food-Contact Materials

“…Pitcher-plant-inspired SLIPSes have a number of advantages over lotus-leaf-inspired superhydrophobic surfaces. Such surfaces have proven to overcome several technical limitations of substrates with well-established superhydrophobic interfaces . Most of the superhydrophobic surfaces can only effectively repel liquids of high surface tension, such as water, and are fully wetted by liquids of low surface tension, whereas SLIPS materials can better manage the removal of low-surface-tension liquids from the surface.…”

Effect of Lubricant Viscosity on Wetting Behaviors and Durability of Anti-icing Slippery Liquid-Infused Porous Surfaces

“…When the viscosity of silicone oil increased, the sliding time of water droplets on SLIPS increased significantly. This is because, for a higher viscosity oil layer, the lubricating ridge causes greater viscous dissipation [8]. Thus, a higher viscosity silicone oil layer has greater resistance against droplet motion.…”