Non-Fluorinated Flexible Superhydrophobic Surface with Excellent Mechanical Durability and Self-Cleaning Performance

ACS Appl Mater Interfaces. 2022 Jan 26;14(3):4750-4758. doi: 10.1021/acsami.1c21840. Epub 2022 Jan 14.

Abstract

Although plenty of superhydrophobic surfaces have been developed owing to their tremendous potential applications, it is still a great challenge for the superhydrophobic surfaces to possess environmental friendliness, biocompatibility, and mechanical durability simultaneously. Herein, a non-fluorinated flexible superhydrophobic surface was designed by constructing a film-substrate system with labyrinth-like wrinkles combining an intrinsically hydrophobic Zn film and a polydimethylsiloxane (PDMS) substrate. Excellent superhydrophobicity with a contact angle up to 168.5° and a slide angle as low as 0° has been achieved on the Zn/PDMS surface, which is attributed to the micro-/nano-textured structures of the labyrinth-like wrinkles, providing sufficient air pockets to form a stable Cassie-Baxter state. Furthermore, the Zn/PDMS surface retains excellent superhydrophobicity under stretching, bending, and twisting mechanical deformation up to 500 cycles due to the stability of the micro-/nano-textured structures of the labyrinth-like wrinkles protected by the fantastic self-healing ability of the micro-cracks. Additionally, the Zn/PDMS superhydrophobic surface possesses an outstanding self-cleaning performance for various contaminants. The present work provides a valuable routine to design non-fluorinated flexible superhydrophobic surfaces with superb mechanical durability and self-cleaning property as promising functional layers for flexible electronics, wearable devices, biomedical engineering, and so forth.

Keywords: flexible surface; mechanical stability; self-cleaning property; superhydrophobic surface; wrinkled pattern.