Designing Impact Resistance and Robustness into Slippery Lubricant Infused Porous Surfaces.

Slippery lubricant infused porous surfaces (SLIPS) have the potential to address daunting challenges such as undesirable surface fouling/biofouling, icing, etc. However, the depletion of lubricants hampers their practical utility. As a solution, here a rational strategy is introduced that operates synergistically in three parts. First, ultra-high capillary pressure is exploited from the reticular structure of metal-organic frameworks (MOFs) with sub-nanometer pores. Second, the need for geometric compatibility is demonstrated; the lubricant chain diameter must be smaller than the MOF pore to enable lubricant chain intercalation. Lastly, the MOF pore chemistry is tailored to achieve a strong intermolecular interaction for any given MOF/lubricant combination. The strategy is investigated through experiments and quantum/molecular simulations, which show that the approach helps lock the intercalated lubricant chains inside the MOF pores and forms a non-conventional supramolecular structure. The resulting SLIPS (including those with fluorine-free chemistry) not only show typical low wetting hysteresis, friction, and ice adhesion but are uniquely resistant to more stringent tests such as continuous dripping and sliding of water droplets (up to 50 hrs), repeated impacts of high-speed water jets (liquid impact Weber number > 4 × 10) and prevent bacterial biofilm formation even in dynamic flow conditions. The findings may widen the practical applications of SLIPS.