*2.2. SLIPS Characterization*

The wetting behavior of SLIPS was determined by measuring the Advancing (ACA) and Receding Contact Angles (RCA) with water and n-hexadecane drops to calculate Contact Angle Hysteresis (CAH) as the difference between the two. Advancing and receding contact angles and contact angle hysteresis with water and n-hexadecane are labeled as ACAW, RCAW, CAHW, ACAH, RCAH, and CAHH in the text. We chose not to measure "static" contact angles, which are commonly reported in most papers about liquidrepellent surfaces, as they do not adequately describe the behavior of liquid drops on SLIPS. Indeed, static contact angles rarely exceed 120◦ on SLIPS, while the low CAH well shows the little adhesion of drops on the surface. Contact angle measurements were performed with an optical contact angle system (DSA 30S, Krüss GmbH, Hamburg, Germany). For all contact angle measurements, 5 μL drops were first dispensed with a software-controlled syringe and gently deposited on the surface. Then, 5 μL were added to the drop and the ACA measured during drop expansion. Finally, 5 μL were removed from the drop and the RCA measured to calculate CAH as the difference between ACA and RCA. For each surface, at least five different points were characterized to calculate average ACA, RCA, and CAH with related standard deviations.

The evolution of chemical composition of coated surfaces was monitored via Fourier Transform Infrared spectroscopy (FTIR) using a Nicolet IS5 spectrophotometer (ThermoFisher Scientific, Waltham, MA, USA) in the Attenuated Total Reflection mode. A diamond crystal was pressed against the samples; each spectrum was collected in the 4000–550 cm−<sup>1</sup> range with a resolution of 4 cm−<sup>1</sup> and averaged over 16 scans. For all spectra, the non-infused face of the pristine sample was used as background to obtain the spectrum of the infused liquid phase.
