Fabrication of Slippery Liquid-Infused Coatings in Flexible Narrow-Bore Tubing.

We report a layer-by-layer suction-and-flow approach that enables the fabrication of polymer-based "slippery" liquid-infused porous surfaces (SLIPS) in the confined luminal spaces of flexible, narrow-bore tubing. These SLIPS-coated tubes can prevent or strongly reduce surface fouling after prolonged contact, storage, or flow of a broad range of complex fluids and viscoelastic materials, including many that are relevant in the contexts of medical devices (e.g., blood and urine), food processing (beverages and fluids), and other commercial and industrial applications. The robust and mechanically compliant nature of the nanoporous coating used to host the lubricating oil phase allows these coated tubes to be bent, flexed, and coiled repeatedly without affecting their inherent slippery and antifouling behaviors. Our results also show that SLIPS-coated tubes can prevent the formation of bacterial biofilms after prolonged and repeated flow-based exposure to the human pathogen Staphylococcus aureus and that the anti-biofouling properties of these coated tubes can be further improved or prolonged by coupling this approach with strategies that permit the sustained release of broad-spectrum antimicrobial agents. The suction-and-flow approach used here enables the application of slippery coatings in the confined luminal spaces of narrow-bore tubing that are difficult to access using several other methods for the fabrication of liquid-infused coatings and can be applied to tubing of arbitrary length and diameter. We anticipate that the materials and approaches reported here will prove useful for reducing or preventing biofouling, process fouling, and the clogging or occlusion of tubing in a wide range of consumer, industrial, and healthcare-oriented applications.