*Article* **Evaluation of the Durability of Slippery, Liquid-Infused Porous Surfaces in Different Aggressive Environments: Influence of the Chemical-Physical Properties of Lubricants**

**Federico Veronesi \*, Guia Guarini, Alessandro Corozzi and Mariarosa Raimondo**

National Research Council—Institute of Science and Technology for Ceramics CNR-ISTEC, 48022 Faenza, Italy; istec@istec.cnr.it (G.G.); alessandro.corozzi@istec.cnr.it (A.C.); mariarosa.raimondo@istec.cnr.it (M.R.) **\*** Correspondence: federico.veronesi@istec.cnr.it; Tel.: +39-054-669-9727

**Abstract:** Liquid-repellent surfaces have been extensively investigated due to their potential application in several fields. Superhydrophobic surfaces achieve outstanding water repellence, however their limited durability in severe operational conditions hinders their large-scale application. The Slippery, Liquid-Infused Porous Surface (SLIPS) approach solves many of the durability problems shown by superhydrophobic surfaces due to the presence of an infused liquid layer. Moreover, SLIPS show enhanced repellence towards low surface tension liquids that superhydrophobic surfaces cannot repel. In this perspective, SLIPS assume significant potential for application in harsh environments; however, a systematic evaluation of their durability in different conditions is still lacking in the literature. In this work, we report the fabrication of SLIPS based on a ceramic porous layer infused with different lubricants, namely perfluoropolyethers with variable viscosity and n-hexadecane; we investigate the durability of these surfaces by monitoring the evolution of their wetting behavior after exposure to severe environmental conditions like UV irradiation, chemically aggressive solutions (acidic, alkaline, and saline), and abrasion. Chemical composition and viscosity of the infused liquids prove decisive in determining SLIPS durability; especially highly viscous infused liquids deliver enhanced resistance to abrasion stress and chemical attack, making them candidates for applicable, long-lasting liquid-repellent surfaces.

**Keywords:** liquid-infused surfaces; durability; lubricants; wetting; liquid-repellent coatings
