Droplets wetting and evaporating on ethanol-philic micro-structured surfaces

摘要

Highlights•Droplet evaporating on micro-structured ethanol-philic surfaces are studies.•Water and ethanol droplets show different wetting states on the structured surfaces.•Four evaporation stages are captured, the duration and transition differ with surface structure.•Evaporation critical time is defined, which increases with structure height.AbstractFour hydrophobic micro-structured surfaces and a polished silicon wafer were tested. First, wettability on different surface morphologies was evaluated. Initial and temporal contact angles were measured. Then, the droplet geometry evolution was monitored. Four evaporation stages were identified. Besides, an evaporation critical time (ECT) was defined. The effects of surface morphology and surface temperature on droplet wetting and evaporating were discussed.