One-Step Fabrication of Flexible Bioinspired Superomniphobic Surfaces

Abstract

Flexible superomniphobic doubly re-entrant (Dual-T) microstructures inspired by springtails have attracted growing attention due to their excellent liquid-repellent properties. However, the simple and practical manufacturing processes of the flexible Dual-T microstructures are urgently needed. Here, we proposed a one-step molding process coupled with the lithography technique to fabricate the elastomeric polydimethylsiloxane (PDMS) Dual-T microstructure surfaces with high uniformity. The angle between the downward overhang and the horizontal direction could reach 90° (vertical overhang). The flexible superomniphobic Dual-T microstructure surfaces, without fluorination treatment and physical treatments, could repel liquids with a surface tension lower than 20 mN m–1 in the Cassie–Baxter state. Owing to the excellent robustness of the one-step molding downward overhanging, the max breakthrough pressure of this surface could reach up to 164.3 Pa for ethanol droplets. Furthermore, the flexible superomniphobic Dual-T surface allowed impinging ethanol droplets to completely rebound at the Weber number up to 7.1 with an impact velocity of ∼0.32 m s–1. The Dual-T microstructure surface maintained excellent superomniphobicity even after surface oxygen plasma treatment and exhibited excellent structural robustness and recoverability to various large mechanical deformations.

Corrosion-Resistant Organic Superamphiphobic Coatings

“…Moreover, on account of its liquid-repellent properties, water or oil droplets can be carried away as they roll, reducing the residence time of pollutants on the coating surface [62]. Zhang et al [63] utilized photolithography to prepare a highly uniform polydimethylsiloxane (PDMS) Dual-T microstructured surface with a downward suspension angle of up to 90 • in the horizontal direction. This flexible superhydrophobic Dual-T microstructure surface, without fluorination treatment, is capable of repelling liquids with a surface tension lower than 20 mN m −1 in the Cassie-Baxter state.…”

Springtail-Inspired Hierarchically Structured Polymer Films as Omniphobic Coatings for Directional Transportation of Liquids

“…To maintain the function of cutaneous respiration, the cuticles of these microparticles are covered with hexagonally arranged nanoscale protrusions and directional microscale ridges. The hierarchical structures have been demonstrated to behave remarkable water/organic liquid-repellent properties and anisotropic self-cleaning capabilities. , Inspired by the springtails, numerous top-down fabrication methodologies are introduced to biomimic the surface morphology of springtail cuticles. − Unfortunately, most of the current photolithography-based technologies are costly, and the as-fabricated nanoscale features seriously suffer from low resolutions. Although electron beam lithography has been exploited to address the issues, the technology is still restricted by the low throughput of products and high-priced commercial masks.…”

Highly selective hydrogen peroxide electrosynthesis on copper phthalocyanine: interface engineering with an azo-polymer

“…Moreover, the catalyst with strong hydrophobicity can suppress the ooding effect of the electrolyte, ensuring a wide oxygen transport channel, which is benecial for maintaining the long-term life of the cathode solid-liquid interface. [62][63][64][65] Fig. 4 (a-c In addition to enhancing the oxygen adsorption capacity by adjusting the hydrophobicity of the electrode surface, the timely desorption of HO 2 − to avoid over-reduction (4e − ORR) (step 2) is also the key for a highly selective H 2 O 2 electrosynthesis.…”