Contactless Rejuvenation of Slippery Lubricant-Infused Surfaces

Slippery liquid-infused porous surfaces (SLIPSs) have demonstrated immense potential for a plethora of applications. While SLIPSs hold great promise for enhancing energy efficiency in thermoelectric and organic Rankine cycle power generation via improved vapor condensation, their application is hindered by inadequate durability. SLIPSs lose their omniphobicity during steam or hydrocarbon condensation due to the depletion of the infused oil with the condensate shedding from the surface. Although SLIPSs employing high-viscosity lubricants can last longer, the eventual loss of slipperiness is inevitable. Here, we demonstrate a contactless spray method to rejuvenate SLIPSs. We study the degradation of SLIPSs fabricated by infusing different viscosity oils and then replenish degraded samples by spraying the respective oils. By conducting a second round of condensation durability tests and heat transfer performance comparisons of the rejuvenated surfaces, we show similar behavior of the rejuvenated surfaces as the freshly prepared SLIPSs. To demonstrate the feasibility of the spray method in a practical scenario, we study the durability of a prototype heat exchanger and show similar performance of the rejuvenated SLIPS heat exchanger as a fresh SLIPS heat exchanger fabricated using traditional dip-coating methods. Our spraying method is independent of physical contact during replenishment and offers a scalable solution for large industrial applications of SLIPSs.