Shortening Droplet Contact Time over a Wider Impact Velocity Range by Molding Flexible Nanohairs and Substrates AITranslate

Basic Information:

DOI：https://doi.org/10.1021/acsapm.1c01000

Chinese Library Classification Number:

Citation Information:

A promising and industrial strategy is proposed for molding flexible nanohairs and substrates to promote the rebound of an impact droplet and shorten its contact time. Replicas are molded for the flexible polypropylene/poly(ethylene-co-octene) [PP/POE; 75/25 and 50/50 (w/w)] blends and the quasi-rigid PP in one step employing injection compression molding with a prepared anodic stainless steel template. The results demonstrate that nanohairs with sharp tips and high aspect ratios are developed on the replica surfaces. The blend replicas exhibit obvious superhydrophobicity (with contact angles of 158–160°), extremely low solid–liquid adhesion, and higher static and dynamic superhydrophobic stability. In a lower impact velocity range, the droplet can early bounce off both blend replica surfaces, stemming from the conversion of stored elastic energy within the flexible nanohairs to the droplet. The contact times on both blend replicas are shortened by ∼21–26% at a 0.44 m/s velocity compared with that on the PP replica. More interestingly, in a higher velocity range, droplet rebound can also be promoted on the blend replicas arranged under cantilever mode, resulting from both elastic-to-kinetic energy conversion and substrate springboard effect. The contact time on the 75/25 PP/POE blend replica is shortened by ∼24% at 2.03 m/s compared with that on the PP replica. This work seems to be the first report of promoting the rebound of impact droplets and shortening their contact times over a wider range of impact velocities via molding a flexible nanostructure on elastic polymer surfaces, which is favorable for various industrial applications, such as anti-icing/frosting, anti-fouling, self-cleaning, and frictional drag reduction.