Fabrication of Polyethylene Superhydrophobic Surfaces by Stretching-Controlled Micromolding

This paper describes a novel process that is stretching‐controlled thermal micromolding, to fabricate bionic superhydrophobic polyethylene films. Low‐density polyethylene was thermally pressed in a vacuum oven onto PDMS stamps replicated from lotus leaves. After being cooled and peeled off from the stamps, the polyethylene films with superhydrophobic surface were created, exhibiting a water contact angle of 154.1 ± 3.5° and a rolling angle of ≈7°. SEM imaging showed that the superhydrophobic surface had micro‐papillas much higher than those on the lotus leaf, demonstrating the papillas had been stretched longer from the holes on the stamp during the separating process. This study shows that micromolding is a promising technique for large scale production of superhydrophobic films, even if the holes on the mold are not deep enough. A polyethylene superhydrophobic surface with high Cassie's papilla was produced by a stretching‐controlled thermal micromolding process using PDMS stamps. The interaction between the polymer and the stamp holes should be responsible for the stretching. This means that superhydrophobic polymer films would be produced in large scale easily only if a stainless rolling mold with randomly but proportionally spaced microholes was created.