Bioinspired Scalable Lubricated Bicontinuous Porous Composites with Self-Recoverability and Exceptional Outdoor Durability

Lubricant-impregnatedsurfaces (LIS) are promising as efficientliquid-repellent surfaces, which comprise a surface lubricant layerstabilized by base solid structures. However, the lubricant layeris susceptible to depletion upon exposure to degrading stimuli, leadingto the loss of functionality. Lubricant depletion becomes even morepronounced in exposed outdoor conditions, restricting LIS to short-termlab-scale applications. Thus, the development of scalable and long-termstable LIS suitable for practical outdoor applications remains challenging.In this work, we designed Lubricated Bicontinuous porous Composites(LuBiCs) by infusing a silicone oil lubricant into a bicontinuousporous composite matrix of tetrapod-shaped zinc oxide microfillersand poly(dimethylsiloxane). LuBiCs are prepared in the meter scaleby a facile drop-casting inspired wet process. The bicontinuous porousfeature of the LuBiCs enables capillarity-driven spontaneous lubricanttransport throughout the surface without any external driving force.Consequently, the LuBiCs can regain liquid-repellent function uponlubricant depletion via capillary replenishment from a small, connectedlubricant reservoir, making them tolerant to lubricant-degrading stimuli(e.g., rain shower, surface wiping, and shearing). As a proof-of-concept,we show that the large-scale LuBiC roof retains slipperybehavior even after more than 9 months of outdoor exposure.

Automated summary

Lubricant-impregnated surfaces (LIS) are efficient liquid-repellent surfaces, but their lubricant layer is susceptible to depletion upon exposure to degrading stimuli. This limits the long-term stability and scalability of LIS. In this work, we developed Lubricated Bicontinuous porous Composites (LuBiCs) by infusing a silicone oil lubricant into a bicontinuous porous composite matrix. LuBiCs can replenish the lubricant via capillary action, allowing them to retain liquid-repellent function even after exposure to degrading stimuli. The large-scale LuBiC roof demonstrated slippery behavior after more than 9 months of outdoor exposure.