Continuous Fabrication of Slippery Liquid-Infused Coatings on Rolls of Flexible Materials

We report continuous, spray-based methods for the fabrication of antifouling “slippery” liquid-infused porous surfaces (SLIPS) on rolls or sheets of thin, flexible materials relevant in a broad range of consumer and industrial applications. Our approach is based on the simultaneous spraying of two reactive polymers and leads to uniform and conformal coatings with (i) useful levels of nano- and microscale porosity and (ii) levels of residual azlactone reactivity that enable the facile introduction of hydrophobic character needed to infuse and retain lubricating oils. This approach can be used to fabricate transparent and mechanically robust SLIPS-based materials that resist fouling by a broad range of fluids and gels, including food-based substances, on rolls of polymer films and foils commonly used to design consumer packaging. These spray-on methods are compatible with continuous (e.g., roll-to-roll) processing approaches used in many commercial and industrial settings. We demonstrate proof of concept of this continuous approach to SLIPS fabrication using a benchtop roll-to-roll setup to coat meter-scale lengths of flexible plastic film. SLIPS-coated film produced using this roll-to-roll approach was then used to design models of flexible food packaging (e.g., transparent bags or sachets), containers, and adhesive “SLIPS-strips” that can be affixed manually to secondary surfaces to impart temporary nonadhesive properties. The approaches reported here enable fabrication of antifouling materials on scales and in forms that would be difficult to achieve using many existing methods for the design of SLIPS and open the door to additional potential practical applications of liquid-infused materials.