Drop impact dynamics on slippery liquid-infused porous surfaces: influence of oil thickness

TL;DR

This study experimentally examines how oil thickness affects the wetting properties and impact dynamics of SLIPS, revealing that thicker oil layers improve homogeneity and influence drop spreading and rebound behavior.

Contribution

It demonstrates the importance of oil layer thickness in optimizing SLIPS performance and impact response, providing new insights into their design.

Findings

Thicker oil layers prevent dewetting spots and improve homogeneity.

Oil thickness significantly influences drop spreading and rebound dynamics.

Optimal oil thickness enhances SLIPS stability and impact behavior.

Abstract

Slippery liquid-infused porous surfaces (SLIPS) are porous nanostructures impregnated with a low surface tension lubricant. They have recently shown great promise in various applications that require non-wettable superhydrophobic surfaces. In this paper, we investigate experimentally the influence of the oil thickness on the wetting properties and drop impact dynamics of new SLIPS. By tuning the thickness of the oil layer deposited through spin-coating, we show that a sufficiently thick layer of oil is necessary to avoid dewetting spots on the porous nanostructure and thus increasing the homogeneity of the liquid distribution. Drop impact on these surfaces is investigated with a particular emphasis on the spreading and rebound dynamics when varying the oil thickness and the Weber number.