具有机械稳定性和自修复性能的滑膜在镁合金上具有潜在的应用前景

Slippery liquid-infused surfaces (SLISs) have the same development potential and application prospects as superhydrophobic surfaces (SHSs) in the fields of corrosion resistance, anti-icing, anti-fouling and drag reduction. However, the durability of SLISs is still a challenge because of the migrating, evaporating, or leaking of the infused liquids. Herein, we proposed a durable polydimethylsiloxane/silicone oil (PDMS-oil) system with mechanical robustness and self-replenishing property. As a demonstration of potential application, the PDMS-oil coating was applied on the magnesium alloy for multi-functions. A layer of PDMS cross-linking network was first cured on the magnesium alloy surface, and then a certain amount of low viscosity dimethyl silicone oil was diffused into the PDMS layer to form the final SLIS coatings. It is found that 50 wt% of silicone oil content is more suitable for the PDMS-oil based slippery coating on Mg alloy, which can maintain a low ice shear strength of less than 30 kPa after 20 icing/deicing cycles and a lower sliding angle of about 30° after wear cycles (under a normal pressure of 10 kPa). Significantly, the proposed PDMS-oil based slippery coating possesses good corrosion resistance and self-replenishing ability, which can also withstand hot water, ice water, and corrosive solutions (i.e. acid and alkaline aqueous solutions). The Mg alloy with the PDMS-oil based slippery coating can remain intact in a 3.5 wt% NaCl aqueous solution even after 20 days at room temperature. It is believed that the Mg alloys with the proposed PDMS-oil based slippery coatings would have more potential applications even in severe environments.