The mechanisms of anti-icing properties degradation for slippery liquid-infused porous surfaces under shear stresses

Abstract

Hypothesis: Loss of anti-icing properties of slippery liquid-infused porous surfaces (SLIPS) in conditions of repetitive shear stresses is the intrinsic process related to peculiarities of SLIPS structure.

Experiments: The study of the evolution of the ice adhesion strength to superhydrophobic surfaces (SHS) and SLIPS during repetitive icing/de-icing cycles measured by a centrifugal method was supplemented with the estimation of change in capillary pressure inside the pores, and SEM analysis of the effect of multiple ice detachments on surface morphology.

Findings: Obtained data indicated that although for freshly prepared SLIPS, the ice shear adhesion strength at -25 °C was several times lower than for SHS, repetitive icing-deicing cycles resulted in dramatic SLIPS degradation. In contrast, SHS showed weak degradation at least during 50 cycles. Additional to the depletion of an impregnating oil layer, other mechanisms of SLIPS degradation were hypothesized and tested. It was shown that lower capillary pressure required to displace air by water from the surface texture for SLIPSs compared to SHSs resulted in deeper water/ice penetration inside the grooves. The accelerated destruction of the mechanical texture caused by the Rehbinder effect constitutes another mechanism of SLIPSs degradation.

Keywords: Adhesion strength; Anti-icing properties degradation; Ice adhesion; Rehbinder effect; Shear stress; Silicone oil; Slippery liquid-infused porous surface; Superhydrophobicity; Wettability.